!version: $Revision: 1.27 $
!date:                 Tue Nov 09 18:39:15 PST 2004
!saved-by: Katica Ilic
!autogenerated-by: DAG-Edit version 1.418
!
!Gene Ontology definitions
!
term: 10 rosette leaf
goid: TAIR:0000413
definition: stage at which the first 10 leaves have reached  > 1mm length.
definition_reference: PMID:11449047

term: 11 rosette leaf
goid: TAIR:0000414
definition: stage at which the first 11 leaves have reached > 1 mm length.
definition_reference: PMID:11449047

term: 12 rosette stage
goid: TAIR:0000415
definition: stage at which the first 12 leaves have reached > 1mm length.
definition_reference: PMID:11449047

term: 13 rosette leaf
goid: TAIR:0000416
definition: stage at which the first 13 leaves have reached > 1mm length.
definition_reference: PMID:11449047

term: 14 rosette leaf
goid: TAIR:0000417
definition: stage at which the first 14 leaves have reached > 1mm length.
definition_reference: PMID:11449047

term: 2 rosette leaf
goid: TAIR:0000398
definition: stage at which the first two rosette leaves have reached > 1 mm in length.
definition_reference: PMID:11449047

term: 3 rosette leaf
goid: TAIR:0000407
definition: stage at which the first 3 rosette leaves have reached > 1 mm in length.
definition_reference: PMID:11449047

term: 4 rosette leaf
goid: TAIR:0000399
definition: stage at which the first 4 rosette leaves have reached > 1mm in length.
definition_reference: PMID:11449047

term: 5 rosette leaf
goid: TAIR:0000408
definition: stage at which the first 5 leaves have reached > 1 mm length.
definition_reference: PMID:11449047

term: 6 rosette leaf
goid: TAIR:0000409
definition: stage at which the first 6 leaves have reached > 1 mm in length.
definition_reference: PMID:11449047

term: 7 rosette leaf
goid: TAIR:0000410
definition: stage at which the first 7 leaves have reached > 1 mm length.
definition_reference: PMID:11449047

term: 8 rosette leaf
goid: TAIR:0000411
definition: stage at which the first 8 leaves have reached > 1 mm length.
definition_reference: PMID:11449047

term: 9 rosette leaf
goid: TAIR:0000412
definition: stage at which the first  9 leaves have reached > 1 mm length.
definition_reference: PMID:1

term: abaxial axillary meristem
goid: TAIR:0000069
definition: The portion of the axillary meristem that is further away from/directed away from the main shoot axis.
definition_reference: TAIR:tb

term: abscission zone
goid: TAIR:0000146
definition: Zone at base of leaf, flower, fruit, or other plant part that contains an abscission (or separation) layer and a protective layer, both involved in the abscission of the plant part.
definition_reference: ISBN:0471245208

term: adaxial axillary meristem
goid: TAIR:0000068
definition: The region of the axillary meristem that is closer to/directed toward the main shoot axis.
definition_reference: TAIR:tb

term: adult leaf
goid: TAIR:0000118
definition: a leaf with waxes, cell types or other features characteristic of leaves in an adult (reproductive )phase
definition_reference: TAIR:lr

term: aerenchyma
goid: TAIR:0000294
definition: Parenchyma tissue containing particularly large intercellular spaces of schizogenous, lysigenous, or rhexigenous origin.
definition_reference: ISBN:0471245208

term: aleurone layer
goid: TAIR:0000308
definition: Outermost layer of endosperm in cereals and many other taxa that contains protein bodies and enzymes concerned with endosperm digestion.
definition_reference: ISBN:0471245208

term: anther
goid: TAIR:0000155
definition: The pollen-bearing part of the stamen.
definition_reference: ISBN:047125208

term: antipodal cell
goid: TAIR:0000192
definition: cells located at the chalazal end of the mature embryo sac in angiosperms
definition_reference: ISBN:047125208

term: aperture
goid: TAIR:0000299
definition: A depressed region in the pollen wall in which thick intine is covered by thin exine; the pollen grain emerges through the aperture.
definition_reference: ISBN:0471245208

term: apical cell
goid: TAIR:0000099
definition: The single cell that occupies the distal position in an apical meristem of root or shoot and is usually interpreted as the initial cell in the apical meristem.
definition_reference: ISBN:0471245208

term: Arabidopsis anatomy
goid: TAIR:0000111
definition: The structure of an organism, specifically Arabidopsis thaliana
definition_reference: TAIR:KI

term: Arabidopsis growth
goid: TAIR:0000205
definition: Stages of growth and development of Arabidopsis
definition_reference: TAIR:lr

term: atrichoblast
goid: TAIR:0000263
definition: A cell formed after asymmetric division of root epidermal cell that does not give rise to a root hair
definition_reference: ISBN:0387987819

term: axial cell
goid: TAIR:0000081
definition: A secondary vascular cell derived from the fusiform cambial initials and oriented with their longest diameter parallel with the main axis of stem or root. These cells make up the axial system, also known as vertical or longitudinal system.
definition_reference: ISBN:0471245208

term: axillary meristem
goid: TAIR:0000232
definition: Meristems formed along the lateral axis of the shoot.
definition_reference: TAIR:lr

term: axillary shoot
goid: TAIR:0000338
definition: shoot formed axillary to the primary shoot meristem.
definition_reference: TAIR:lr

term: basal cell
goid: TAIR:0000179
definition: the lowermost cell formed after the first division of the zygote.
definition_reference: TAIR:lr

term: basal internode
goid: TAIR:0000073
definition: The internode located closest to the base of the stem.
definition_reference: TAIR:tb

term: body part developmental stages
goid: TAIR:0000022
definition: stages of development of a part or parts of a plant defined by characteristic morphological, structural, histological or other visible features. 
definition_reference: TAIR:lr

term: bulliform cell
goid: TAIR:0000102
definition: An enlarged epidermal cell present, with other similar cells, in longitudinal rows in leaves of grasses. Also called motor cell because of its presumed participation in the mechanism of rolling and unrolling of leaves.
definition_reference: ISBN:0471245208

term: bundle sheath
goid: TAIR:0000023
definition: Layer or layer of cells enclosing the vascular bundle in a leaf; may consist of parenchyma or sclerenchyma.
definition_reference: ISBN:0471245208

term: callus tissue
goid: TAIR:0000038
definition: A tissue composed of large thin-walled cells developing as a result of injury, as in wound healing or grafting,  and in tissue culture.
definition_reference: ISBN:0471245208

term: cambial initial
goid: TAIR:0000295
definition: Cells so localized in the vascular cambium or phellogen that their periclinal divisions can contribute cells either to the outside or to the inside of the axis; in vascular cambium, classified into fusiform initials (source of axial cells of xylem and phloem) and ray initials (source of the ray cells).
definition_reference: ISBN:0471245208

term: carpel
goid: TAIR:0000126
definition: Leaf like organ in angiosperms producing one or more ovules; a constituent of the gynoecium.
definition_reference: ISBN:0471245208

term: casparian strip
goid: TAIR:0000257
definition: A band like wall formation within primary walls that contains suberin and lignin; typical of endodermal cells in roots, in which it occurs in radial and transverse anticlinal walls.
definition_reference: ISBN:0471245208

term: cauline leaf
goid: TAIR:0000090
definition: Stem leaf, produced before the transition to flowering, lacking a petiole.
definition_reference: ISBN:0387940898

term: cellular endosperm
goid: TAIR:0000199
definition: Endosperm in which cell walls have formed around the nuclei of the tissue.
definition_reference: TAIR:tb

term: central cell
goid: TAIR:0000194
definition: cell type containing the two polar nuclei which, after double fertilization, will develop into the endosperm.
definition_reference: TAIR:lr

term: central root cap
goid: TAIR:0000254
definition: The central part of a root cap in which the cells are arranged in longitudinal files.
definition_reference: ISBN:0471245208

term: central zone
goid: TAIR:0000224
definition: An area of densely cytoplasmic cells that divide infrequently. Functions as a population of stem cells that replenishes the meristem.
definition_reference: TAIR:lr
definition_reference: ISBN:0521288959

term: chalaza
goid: TAIR:0000237
definition: Region in the ovule opposite the micropyle where the integuments and the nucellus merge with the funiculus.
definition_reference: ISBN:047125208

term: chalazal endosperm
goid: TAIR:0000201
definition: the portion of the endosperm located nearest the chalazal region of the ovule.
definition_reference: TAIR:lr
definition_reference: ISBN:0471245208

term: chlorenchyma
goid: TAIR:0000241
definition: Parenchyma  containing chloroplasts; a component of leaf mesophyll and other green parenchyma.
definition_reference: ISBN:0471245208

term: chlorenchyma cell
goid: TAIR:0000076
definition: Parenchyma cells containng chloroplasts; a component of leaf mesophyll and other green parenchyma tissue.
definition_reference: ISBN:0471245208

term: collenchyma
goid: TAIR:0000209
definition: A supporting tissue composed of more or less elongated living cells with unevenly thickened nonlignified primary walls. Common in regions of primary growth in stems and leaves.
definition_reference: ISBN:0471245208

term: collenchyma cell
goid: TAIR:0000075
definition: Elongated living cells with unevenly thickened nonlignified primary walls.
definition_reference: ISBN:0471245208

term: companion cell
goid: TAIR:0000071
definition: A specialized parenchyma cell associated with a sieve-tube member in angiosperm phloem and arising from the same mother cell as the sieve-tube member.
definition_reference: ISBN:0879015322

term: complete rosette
goid: TAIR:0000418
definition: stage at which leaf growth has ceased and the rosette no longer increases in size.
definition_reference: PMID:11449047

term: contact cell
goid: TAIR:0000105
definition: An axial parenchyma or a ray cell physiologically associated with a tracheary element. Also a cell next to a stoma.
definition_reference: ISBN:0471245208

term: cork cell
goid: TAIR:0000106
definition: A phellem cell derived from the phellogen, nonliving at maturity, and having suberized walls; protective in function because the walls are highly impervious to water.
definition_reference: ISBN:0471245208

term: cotyledon
goid: TAIR:0000138
definition: Leaf or leaf-like organ formed during embryogenesis. Specialization includes accumulation of storage reserves that are mobilized during seed germination.
definition_reference: TAIR:lr

term: cotyledon abaxial epidermis
goid: TAIR:0000211
definition: epidermal layer of the cotyledon facing away from the axis.
definition_reference: TAIR:lr

term: cotyledon adaxial epidermis
goid: TAIR:0000210
definition: epidermal layer located on the side of the cotyledon facing the axis,
definition_reference: TAIR:lr

term: cotyledon primordium
goid: TAIR:0000365
definition: the earliest differentiated state of a cotyledon.
definition_reference: TAIR:lr
definition_reference: ISBN:047125208

term: cotyledon vascular system
goid: TAIR:0000119
definition: vascular system formed in cotyledons
definition_reference: TAIR:lr

term: curled cotyledon stage
goid: TAIR:0000320
definition: The stage at which the cotyledons curve down towards the suspensor. At this time protein deposition in the cotyledons begins.
definition_reference: ISBN:0387940898

term: degenerate megaspore
goid: TAIR:0000245
definition: in monosporic and bisporic megasporogenesis: the megaspore(s) that do not participate in megagametogenesis.
definition_reference: TAIR:lr

term: dermatogen stage
goid: TAIR:0000369
definition: The stage at which the embryo has undergone three mitotic divisions and contains sixteen cells. The outer protodermal cells will give rise to the epidermis through a series of anticlinal divisions. Development of the suspensor is complete at this stage.
definition_reference: ISBN:0387094898

term: dry seed
goid: TAIR:0000213
definition: Stage during which the seed has attained less than 20% of water content, entering into metabolically inactive or, quiescent state.
definition_reference: TAIR:ki

term: early seed development
goid: TAIR:0000171
definition: Early stage of seed development (commencing with the formation of diploid zygote) during which embryonic organ system is established, i.e., embryo axis and cotyledons. This stage terminates with apical-basal elongation of the embryo resulting in green linear embryo with flattened cotyledons. The seed coat is light green at this stage.
definition_reference: TAIR:ki

term: egg apparatus
goid: TAIR:0000189
definition: The egg cell and two synergids located at the micropylar end of the female gametophyte, or the embryo sac, in angiosperms.
definition_reference: ISBN:047125208

term: egg cell
goid: TAIR:0000190
definition: the female gamete
definition_reference: TAIR:lr

term: eight-celled stage
goid: TAIR:0000180
definition: An embryo comprised of eight cell. The mitotic divisions leading to this stage do not cause a significant increase in size.
definition_reference: ISBN:0387094898

term: elongation zone
goid: TAIR:0000324
definition: the portion of the root that includes small, densely cytoplasmic cells that are dividing and expanding in size.
definition_reference: ISBN:0879694289

term: elongation zone of the internode
goid: TAIR:0000072
definition: The region of the internode that undergoes growth either by cell division or cell expansion.
definition_reference: TAIR:tb

term: embryonic
goid: TAIR:0000374
definition: stages of development that occur after fertilization and before germination.
definition_reference: TAIR:lr

term: embryonic apical cell
goid: TAIR:0000178
definition: the uppermost cell formed after the first division of the zygote.
definition_reference: TAIR:lr

term: embryonic axis
goid: TAIR:0000387
definition: the stem component of the embryo.
definition_reference: TAIR:lr

term: embryonic ground tissue
goid: TAIR:0000367
definition: ground tissue (parenchymatous) layers found in the embryo.
definition_reference: TAIR:lr

term: endocarp
goid: TAIR:0000094
definition: The innermost layer or layers of the pericarp.
definition_reference: ISBN:0471245208

term: endodermis
goid: TAIR:0000003
definition:  It is the innermost layer of the cortex in roots and stems of seed plants.
definition_reference: ISBN:047124520

term: endosperm
goid: TAIR:0000197
definition: The nutritive tissue formed within the embryo sac of angiosperms from the central cell containing the primary endosperm nucleus.
definition_reference: ISBN:047125208

term: endothecium
goid: TAIR:0000158
definition: A wall layer in the anther, usually with secondary wall thickenings.
definition_reference: TAIR:047125208

term: epidermal cell
goid: TAIR:0000100
definition: Cell that constitutes dermal tissue.
definition_reference: TAIR:KI

term: epidermal initial
goid: TAIR:0000349
definition: a relatively unspecialized cell that will give rise to specialized cell types of the epidermis
definition_reference: TAIR:lr

term: epidermis
goid: TAIR:0000202
definition: the outer layer of cells in the plant body, primary in origin. 
definition_reference: ISBN:0471245208

term: epithelium cell
goid: TAIR:0000144
definition: A compact layer of cells, often secretory in function, covering a free\nsurface or lining a cavity.
definition_reference: ISBN:0471245208

term: epithem cell
goid: TAIR:0000066
definition: Cells that constitute the mesophyll of a hydathode and are located between the xylem endings and the epidermis. Proposed to be involved in the retrieval of solutes from the xylem sap.
definition_reference: PMID:12662305
definition_reference: ISBN:0471245208

term: exocarp
goid: TAIR:0000095
definition: The outermost layer or layers of the pericarp.
definition_reference: ISBN:0471245208

term: fascicular cambium
goid: TAIR:0000360
definition: Vascular cambium originating from procambium within a vascular bundle, or fascicle.
definition_reference: ISBN:0471245208

term: fiber tracheid
goid: TAIR:0000355
definition: A fiber like tracheid in the secondary xylem; commonly thick walled, with pointed ends and bordered pits that have lenticular to slit like apertures.
definition_reference: ISBN:0471245208

term: filliform apparatus
goid: TAIR:0000193
definition: A complex of cell wall invaginations in a synergid cell similar to those in transfer cells.
definition_reference: ISBN:0471245208

term: first open flower
goid: TAIR:0000421
definition: whole plant stage at which the first flower has reached stage 13 (fully open, pollen dehiscence).
definition_reference: PMID:11449047

term: floral organ
goid: TAIR:0000122
definition: an organ that is part of the flower: the sexual reproductive structure of Angiosperms.
definition_reference: TAIR:lr

term: flower development
goid: TAIR:0000004
definition: stages of flower development in Arabidopsis
definition_reference: ISBN:0387940898

term: free nuclear endosperm
goid: TAIR:0000198
definition: A multinucleate endosperm.
definition_reference: TAIR:syr

term: fully expanded leaf stage
goid: TAIR:0000053
definition: Stage of leaf development stage where the leaf is fully expanded, no longer increases in size by cell division and/or cell expansion and is metabolically active.
definition_reference: TAIR:tb

term: functional megaspore
goid: TAIR:0000244
definition: in monosporic and bisporic megasporogenesis: the megaspore(s) that will undergo megagametogenesis.
definition_reference: TAIR:lr

term: funiculus
goid: TAIR:0000239
definition: The stalk of the ovule.
definition_reference: ISBN:0471245208

term: fusiform initial
goid: TAIR:0000079
definition: An elongated cell with approximately wedge-shaped ends, found in the vascular cambium, which gives rise to the elements of the axial system in the secondary vascular tissues.
definition_reference: ISBN:0471245208

term: gametophyte
goid: TAIR:0000427
definition: the haploid organism (or phase) which bears (forms)the gametes,
definition_reference: TAIR:lr

term: generative cell
goid: TAIR:0000168
definition: The cell that will give rise to two sperm cells which will participate in double fertilization.
definition_reference: TAIR:KI

term: germinated pollen grain
goid: TAIR:0000085
definition: The final stage in the life cycle of the male gametophyte. Upon rehydration, mature pollen grain forms tubular outgrowth, pollen tube, which carries male gametes.
definition_reference: TAIR:KI

term: globular stage
goid: TAIR:0000028
definition: A collective term referring to the stages of embryo development spanning the early globular stage when the protoderm is formed to the late globular stage (before the initial divisions of the cotyledon primordia
definition_reference: ISBN:0387940898

term: guard cell
goid: TAIR:0000293
definition: one of a pair of cells flanking the stomatal pore and causing the opening and closing of the pore by changes in turgor.
definition_reference: ISBN:0471245208

term: guard mother cell
goid: TAIR:0000351
definition: epidermal cell that that divides to produce the guard cells.
definition_reference: ISBN:0471245208

term: gynoecium
goid: TAIR:0000326
definition: Collective term for the carpels in an angiosperm flower; part of the flower in which female gametogenesis occurs.
definition_reference: ISBN:0471245208

term: heart stage
goid: TAIR:0000186
definition: Embryonic stage at which the cotyledon primordia have enlarged enough to form two mounds on either side of the apical meristem.
definition_reference: ISBN:03870940898
definition_reference: TAIR:lr

term: hydathode
goid: TAIR:0000323
definition: A structural modification of vascular and ground tissues, usually in a leaf, that permits the release of water through a pore in the epidermis; may be secretory in function. 
definition_reference: TAIR:lr

term: hypocotyl
goid: TAIR:0000310
definition: the axial part of the embryo or seedling located between the cotyledon or cotyledons and the radicle.
definition_reference: ISBN:0471245208

term: hypophysis
goid: TAIR:0000181
definition: The uppermost cell of suspensor from which part of the root and root cap in the embryo of angiosperms are derived.
definition_reference: ISBN:047125208

term: idioblast
goid: TAIR:0000283
definition: A cell in a tissue that markedly differs in form, size, or contents from other cells in the same tissue.
definition_reference: ISBN:0471245208

term: initial cell
goid: TAIR:0000098
definition: Cell in a meristem that by division gives rise to two cells one of which remains in the meristem, the other is added to the plant body
definition_reference: ISBN:0471245208

term: inner epidermis
goid: TAIR:0000137
definition: A layer of epidermal cells in the ovary wall that undergo successive periclinal divisions and whose derivatives form the mature endocarp.
definition_reference: TAIR:KI

term: internode
goid: TAIR:0000116
definition: The region betwen nodes of a stem.
definition_reference: ISBN:0471245208

term: juvenile leaf
goid: TAIR:0000216
definition: a leaf with cellular or morphological or anatomical characteristics of a juvenile (non-reproductive) plant.
definition_reference: TAIR:lr

term: lamina
goid: TAIR:0000221
definition: Blade, or expanded part of the leaf.
definition_reference: ISBN:0471245208

term: late globular stage
goid: TAIR:0000185
definition:  At this stage the protoderm, procambium, hyposeal cell are present and the endosperm begins to cellularize.
definition_reference: ISBN:03870940898

term: late reproductive
goid: TAIR:0000026
definition: reproductive stages that occur after the midpoint and before senescence or the end of reproductive growth.
definition_reference: TAIR:lr

term: lateral root meristem
goid: TAIR:0000031
definition: The meristem found in lateral roots.
definition_reference: TAIR:lr

term: lateral root primordium
goid: TAIR:0000032
definition: An organized group of cells derived from the root pericycle that will differentiate into a new root,
definition_reference: TAIR:lr

term: lateral root tip
goid: TAIR:0000067
definition: The portion of the lateral root including the meristem and root cap.
definition_reference: TAIR:lr

term: laticiferous cell
goid: TAIR:0000110
definition: A specialized cells or ducts resembling vessels; they form branched networks of latex-secreting cells in the phloem and other parts of plants.
definition_reference: Web::http://academic.kellogg.edu/herbrandsonc/bio111/glossary/glossary.htm

term: leaf development
goid: TAIR:0000050
definition: stages of leaf development in Arabidopsis
definition_reference: TAIR:tb

term: leaf expansion stage
goid: TAIR:0000052
definition: Stage of leaf development which begins when the leaf primordiumis visible on the shoot apex and continues throughout the time that it increases in size by cell division and/or cell expansion.
definition_reference: TAIR:tb

term: leaf initiation stage
goid: TAIR:0000051
definition: Stage of leaf development that begins when cells are set aside in the meristem to form the leaf primordium and ends right before the leaf primordium is visible on the shoot apex.  Cells in the primordium are not yet differentiated.
definition_reference: TAIR:tb

term: leaf senescence stage
goid: TAIR:0000054
definition: the final stage of leaf development where the leaf ceases metabolic activity and senesces
definition_reference: TAIR:tb

term: lenticel
goid: TAIR:0000292
definition: An isolated region in the periderm distinguished from the phellem in having intercellular spaces; the tissue may or may not be suberized.
definition_reference: ISBN:0471245208

term: lower tier
goid: TAIR:0000321
definition:  cells formed by division of the embryonic apical cell that are distal to the apex.
definition_reference: ISBN:0879694289
definition_reference: TAIR:lr

term: mature
goid: TAIR:0000368
definition: Stage at which the embryo has ceased to divide. 
definition_reference: ISBN:0387940898

term: megagametophyte
goid: TAIR:0000188
definition: Haploid generation that produces the gametes in higher plants, Female gametophyte in heterosporous plants; embryo sac within the ovule in angiosperms.
definition_reference: ISBN:047125208
definition_reference: TAIR:lr

term: megaspore
goid: TAIR:0000243
definition: A haploid (1n) spore developing into a female gametophyte in heterosporous plants.
definition_reference: ISBN:0471245208

term: megasporocyte
goid: TAIR:0000431
definition: A diploid (2n) cell that undergoes meiosis and produces four haploid (1n) megaspores; also called megaspore mother cell.
definition_reference: ISBN:0471245208

term: meristematic cell
goid: TAIR:0000103
definition: A cell synthesizing protoplasm and producing new cells by division; varies in form, size, wall thickness, and degree of vacuolation, but has only a primary cell wall.
definition_reference: ISBN:0471245208

term: meristematic zone
goid: TAIR:0000092
definition: Zone of cell division
definition_reference: TAIR:KI

term: meristemoid
goid: TAIR:0000070
definition: A cell or a group of cells constituting an active locus of meristematic activity in a tissue composed of somewhat older, differentiating cells.
definition_reference: TAIR:syr
definition_reference: ISBN:0471245208

term: mesocarp
goid: TAIR:0000096
definition: The middle layer of the pericarp.
definition_reference: ISBN:0471245208

term: mesophyll cell
goid: TAIR:0000104
definition: Cell that constitute leaf mesophyll.
definition_reference: TAIR:KI

term: metaphloem
goid: TAIR:0000279
definition: Part of the primary phloem that differentiates after the protophloem and before the secondary phloem, if any of the latter is formed in a given taxon.
definition_reference: TAIR:047125208

term: metaxylem
goid: TAIR:0000372
definition: Part of the primary xylem that differentiates after the protoxylem and before the secondary xylem, if any of the latter is formed in a given taxon.
definition_reference: ISBN:047125208

term: micropylar endosperm
goid: TAIR:0000200
definition: the region of the endosperm closest to the micropylar region of the ovule.
definition_reference: TAIR:lr

term: micropyle
goid: TAIR:0000238
definition: The opening in the integuments of an ovule through which the pollen tube usually enters the embryo sac.
definition_reference: ISBN:047125208

term: microspore
goid: TAIR:0000297
definition: A haploid (1n) spore developing into a male gametophyte in heterosporous plants; the uninucleate pollen grain in seed plants.
definition_reference: ISBN:0471245208

term: microsporocyte
goid: TAIR:0000160
definition: A diploid (2n) cell that undergoes meiosis and forms four haploid (1n) microspores; also called microspore mother cell and, in seed plants, pollen mother cell.
definition_reference: ISBN:0471245208

term: mid reproductive
goid: TAIR:0000025
definition: middle stages of reproductive phase
definition_reference: TAIR:lr

term: mid-globular stage
goid: TAIR:0000184
definition: Stage at which the embryo under goes mitotic divisions to produce a 32 then 64- celled embryo.
definition_reference: ISBN:03870940898

term: midvein
goid: TAIR:0000235
definition: the central or usually most prominent vein in a leaf or leaf-like organ.
definition_reference: TAIR:lr

term: mucilage cell
goid: TAIR:0000373
definition: Cell containing mucilages or gums or similar carbohydrate material characterized by the property of swelling in water.
definition_reference: ISBN:0471245208

term: myrosin cell
goid: TAIR:0000352
definition: Cell containing glucosinolates ("mustard oil glucosides") and myrosinases, enzymes hydrolyzing the glucosinolates. Occurs in eleven dicotyledon families, the two largest of which are the Brassicaceae and Euphorbiaceae.
definition_reference: ISBN:0471245208

term: nectary
goid: TAIR:0000123
definition: A multicellular glandular structure secreting a liquid containing organic substances including sugar. Occurs in flowers (floral nectary) and on vegetative plant parts (extrafloral nectary).
definition_reference: ISBN:0471245208

term: nectary epidermis
goid: TAIR:0000207
definition: the epidermal layer of the nectary.
definition_reference: TAIR:lr

term: nectary parenchyma
goid: TAIR:0000309
definition: the ground tissue of the nectary.
definition_reference: TAIR:lr

term: node
goid: TAIR:0000344
definition: the part of the stem at  which one or more leaves are attached; not sharply delimited anatomically.
definition_reference: ISBN:0471245208

term: nucellus
goid: TAIR:0000240
definition: Inner part of an ovule in which the embryo sac develops. Commonly considered to be equivalent to the megasporangium.
definition_reference: ISBN:047125208

term: outer epidermis
goid: TAIR:0000139
definition: outer epidermal layer of the ovary wall.
definition_reference: TAIR:lr

term: ovary
goid: TAIR:0000128
definition: Lower part of a carpel (simple pistil) or of a gynoecium composed of united carpels (compound pistil) containing the ovules and differentiating into the fruit.
definition_reference: ISBN:0471245208

term: ovary ground tissue
goid: TAIR:0000163
definition: the ground tissue layer of the ovary.
definition_reference: TAIR:lr

term: ovary parenchyma
goid: TAIR:0000242
definition: parenchyma layer of the ovary wall.
definition_reference: TAIR:lr

term: ovary vascular system
goid: TAIR:0000129
definition: vascular system of the ovary
definition_reference: TAIR:lr

term: ovule
goid: TAIR:0000236
definition: A structure in seed plants enclosing the female gametophyte and composed of the nucellus, one or two integuments, and funiculus; differentiates into the seed.
definition_reference: ISBN:0471245208

term: ovule development
goid: TAIR:0000005
definition: stages of ovule and megagametophyte development
definition_reference: PMID:9118807

term: ovule stage 1-I
goid: TAIR:0000006
definition: ovule primordia arise
definition_reference: TAIR:publication 11808

term: ovule stage 1-II
goid: TAIR:0000007
definition: ovule primordium elongate
definition_reference: TAIR:publication 11808

term: ovule stage 2-I
goid: TAIR:0000008
definition: megaspore mother cell enlarges
definition_reference: TAIR:publication 11808

term: ovule stage 2-II
goid: TAIR:0000009
definition: inner integument initiates
definition_reference: TAIR:publication 11808

term: ovule stage 2-III
goid: TAIR:0000010
definition: outer integument initiates, chalazal nucellus divides
definition_reference: TAIR:publication 11808

term: ovule stage 2-IV
goid: TAIR:0000011
definition: megaspore meiosis occurs
definition_reference: TAIR:publication 11808

term: ovule stage 2-V
goid: TAIR:0000012
definition: tetrad of megaspores formed, integuments elongate towards apex of the nucellus
definition_reference: TAIR:publication 11808

term: ovule stage 3-I
goid: TAIR:0000013
definition: non-functional megaspores degenerate, outer integument envelops the nucellus and inner integument, funiculus and nucellus begin to curve
definition_reference: TAIR:publication 11808

term: ovule stage 3-II
goid: TAIR:0000014
definition: two nucleate megagametophyte stage, outer integument surrounds nucellus, micropylar end points > 90 degrees away from funiculus, differential growth of integuments
definition_reference: TAIR:publication 11808

term: ovule stage 3-III
goid: TAIR:0000015
definition: megagametophyte develops large central vacuole, micropylar end of ovule at 90 degree angle from funiculus
definition_reference: TAIR:publication 11808

term: ovule stage 3-IV
goid: TAIR:0000016
definition: four-nucleate megagametophyte , inner integument surrounds nucellus, endothelium differentiates
definition_reference: TAIR:publication 11808

term: ovule stage 3-V
goid: TAIR:0000017
definition: eight nucleate megagametophyte
definition_reference: TAIR:publication 11808

term: ovule stage 3-VI
goid: TAIR:0000018
definition: central cell nuclei fuse, antipodal cells degenerate, additional cell layer forms in inner integument
definition_reference: TAIR:publication 11808

term: palisade parenchyma
goid: TAIR:0000342
definition: Leaf mesophyll parenchyma characterized by elongated form of cells and their arrangement with their long axes perpendicular to the surface of the leaf.
definition_reference: ISBN:0471245208

term: parenchyma
goid: TAIR:0000343
definition: A tissue composed of parenchyma cells.
definition_reference: TAIR:KI

term: parenchyma cell
goid: TAIR:0000074
definition: Typically this is a not distinctly specialized cell with a nucleate protoplast concerned with one or more of the various physiological and biochemical activities in plants. Varies in size, form, and wall structure.
definition_reference: ISBN:0471245208

term: passage cell
goid: TAIR:0000353
definition: Cell in exodermis or endodermis that remains thin walled when the associated cells develop thick secondary walls. Has casparian strip in endodermis.
definition_reference: ISBN:0471245208

term: pavement cell
goid: TAIR:0000332
definition: epidermal cells with a characteristic convoluted anticlinal cell walls that give a jigsaw like appearance to the lamina.
definition_reference: ISBN:087694289

term: pedicel
goid: TAIR:0000220
definition: The stalk of an individual flower.
definition_reference: ISBN:0471245208

term: pericarp
goid: TAIR:0000347
definition:  Fruit wall developed from the ovary wall.
definition_reference: ISBN:0471245208

term: pericycle
goid: TAIR:0000260
definition: Part of ground tissue of the stele located between the phloem and the endodermis. In seed plants, regularly present in roots, absent in most stems.
definition_reference: ISBN:0471245208

term: peripheral zone
goid: TAIR:0000225
definition: organogenic region of the meristem. characterized by higher rates of cell division.
definition_reference: TAIR:lr
definition_reference: ISBN:0521288959

term: petal
goid: TAIR:0000124
definition: A unit of the corolla of a flower.
definition_reference: ISBN:0471245208

term: petal parenchyma
goid: TAIR:0000234
definition: the ground tissue of the petal.
definition_reference: TAIR:lr

term: petiole
goid: TAIR:0000121
definition: the stalk of a leaf.
definition_reference: ISBN:0471245208

term: phelloid cell
goid: TAIR:0000107
definition: A cell within the phellem (cork) but distinct from the cork cell in having no suberin in its walls.
definition_reference: ISBN:0471245208

term: phloem
goid: TAIR:0000278
definition: The principal food-conducting tissue of the vascular plant composed mainly of sieve elements, various kinds of parenchyma cells, fibers, and sclereids.
definition_reference: ISBN:047125208

term: phloem initial
goid: TAIR:0000400
definition: A cambial cell on the phloem side of the cambial zone that is the source of one or more cells arising by periclinal divisions and differentiating into phloem elements with or without additional divisions in various planes. Sometimes called phloem mother cell.
definition_reference: ISBN:0471245208

term: phloem parenchyma
goid: TAIR:0000359
definition: parenchyma tissue found in the phloem.
definition_reference: TAIR:lr

term: photosynthetic cell
goid: TAIR:0000108
definition: A chloroplast-containing cell engaged in photosynthesis.
definition_reference: ISBN:0471245208

term: polar nucleus
goid: TAIR:0000196
definition: One of two nuclei in the central cell of a mature embryo sac. The two nuclei are derived from groups of nuclei at the two opposite poles of the eight-nucleate embryo sac.
definition_reference: ISBN:047125208

term: pollen development
goid: TAIR:0000055
definition: The stages of pollen development in Arabidopsis.
definition_reference: TAIR:tb

term: pollen sac
goid: TAIR:0000156
definition: Sporangium in which microspores are formed; anther locule and its walls in angiosperms.
definition_reference: ISBN:047125208

term: pollen stage 1
goid: TAIR:0000056
definition: Stage of microgametogenesis where the archesporial cells divide to give rise to primary parietal and sporogenous cells.
definition_reference: ISBN:0387940898

term: pollen stage 10
goid: TAIR:0000065
definition: Stage of microsporogenesis during which the pollen grains mature and dessicate.  The tapetal layer disappears just prior to dehiscence of the anther.
definition_reference: ISBN:0387940898
definition_reference: PMID:12354970

term: pollen stage 2
goid: TAIR:0000057
definition: Stage of microsporogenesis where the microsporocytes become conspicuous.
definition_reference: ISBN:0387940898

term: pollen stage 3
goid: TAIR:0000058
definition: Stage of microsporogenesis where the pollen mother cells become separated from each other and from tapetum by a callose wall.
definition_reference: ISBN:0387940898

term: pollen stage 4
goid: TAIR:0000059
definition: Stage of microsporogenesis where pollen mother cells undergo meiosis to form isobilateral and tetrahedral tetrads of microspores that are enclosed by the callose wall.
definition_reference: ISBN:0387940898
definition_reference: PMID:12354970

term: pollen stage 5
goid: TAIR:0000060
definition: Stage of microsporogenesis just after pollen mother cell meiosis during which the callose wall between the tetrads breaks down and the microspores are released and lie freely in the pollen sac.
definition_reference: PMID:12354970
definition_reference: ISBN:0387940898

term: pollen stage 6
goid: TAIR:0000061
definition: Stage of microsporogenesis where the microspores round up and small vaualoles appear in their cytoplasm.  The cell walls also thicken because of the formation of the exine.
definition_reference: PMID:12354970

term: pollen stage 7
goid: TAIR:0000062
definition: Stage of microsporogenesis where a large vacuole is formed in each microspore causing a rapid increase in size and a displacement of the nucleus to one side.
definition_reference: PMID:12354970

term: pollen stage 8
goid: TAIR:0000063
definition: Stage of microsporogenesis during which the resorption of the prominent vacuole occurs followed by the first mitotic division of th microspores occurs, 
definition_reference: ISBN:0387940898
definition_reference: PMID:12354970

term: pollen stage 9
goid: TAIR:0000064
definition: Stage of microsporogenesis during which the second mitotic division of the microsporocyte occurs.  Storage bodies become visible in the microspores.
definition_reference: PMID:12354970
definition_reference: ISBN:0387940898

term: pollen tube
goid: TAIR:0000086
definition: A tube-like structure formed after germination of the pollen grain; carries the male gametes into the ovule.
definition_reference: TAIR:KI

term: primary endosperm nucleus
goid: TAIR:0000195
definition: Nucleus resulting from the fusion of the male gamete and two polar nuclei in the central cell of the embryo sac.
definition_reference: ISBN:0471245208

term: primary phloem
goid: TAIR:0000280
definition: Phloem tissue differentiating from procambium during primary growth and differentiation of a vascular plant. Commonly divided into the earlier protophloem and the later metaphloem. Not differentiated into axial and ray systems.
definition_reference: ISBN:047125208

term: primary root meristem
goid: TAIR:0000030
definition: The region located at the distal end of the root containing actively dividing cells that produce new tissues of the root. The primary root meristem is formed in the embryo (the basal end of the shoot-root axis), in contrast to lateral root meristems.
definition_reference: TAIR:lr

term: procambium
goid: TAIR:0000345
definition:  Primary meristem or meristematic tissue which differentiates into the primary vascular tissue. Also called provascular tissue.
definition_reference: ISBN:047125208

term: protoderm
goid: TAIR:0000182
definition: Primary meristem or meristematic tissue giving rise to the epidermis; also epidermis in meristematic state. May or may not arise from independent initials in the apical meristem.
definition_reference: ISBN:0471245208

term: protophloem
goid: TAIR:0000346
definition: the first-formed elements of the phloem in a plant organ. First part of the primary phloem.
definition_reference: ISBN:0471245208

term: protoxylem
goid: TAIR:0000272
definition: The first formed elements of the xylem in a plant organ. First part of the primary xylem.
definition_reference: ISBN:047125208

term: quiescent center
goid: TAIR:0000259
definition: The initial region in the apical meristem that has reached a state of relative inactivity; common in roots.
definition_reference: ISBN:0471245208

term: radicle
goid: TAIR:0000268
definition: the embryonic root. Forms the basal continuation of the hypocotyl in an embryo.
definition_reference: ISBN:0471245208

term: raphe
goid: TAIR:0000364
definition:  A ridge along the body of the seed formed by the part of the funiculus that is adnate to the ovule (in an anatropous ovule).
definition_reference: ISBN:0471245208

term: ray cell
goid: TAIR:0000083
definition: A cell derived from the ray initial and composes all rays (panels of tissue variable in height and width, formed by the ray initials in the vascular cambium and extending radially in the secondary xylem and secondary phloem) in the secondary vascular tissues.
definition_reference: ISBN:0471245208

term: ray initial
goid: TAIR:0000082
definition: A meristematic ray cell in the vascular cambium that gives rise to ray cells of the secondary xylem and secondary phloem.
definition_reference: ISBN:0471245208

term: replum
goid: TAIR:0000135
definition: in an ovary or fruit, a false septum formed by ingrowth from the placenta rather than from the carpel walls.
definition_reference: ISBN:0140514031

term: reproductive
goid: TAIR:0000306
definition: In annual plants the stages that commence when the plant is capable of sexual reproduction (e.g. flowering) and continues until sexual reproduction ceases.
definition_reference: TAIR:lr

term: rib zone
goid: TAIR:0000226
definition: region of the meristem that lies below the central zone and within the peripheral zone
definition_reference: ISBN:0521288959
definition_reference: TAIR:lr

term: root cap
goid: TAIR:0000253
definition:  A thimble like mass of cells covering the apical meristem of the root.
definition_reference: ISBN:047125208

term: root cortex
goid: TAIR:0000258
definition: the primary tissue located between the vascular system and the epidermis.
definition_reference: ISBN:047125208

term: root endodermis
goid: TAIR:0000252
definition: The layer of ground tissue forming a sheath around the vascular region and having the casparian strip in its anticlinal walls; may have secondary walls later. It is the innermost layer of the cortex in roots and stems of seed plants.
definition_reference: ISBN:0471245208

term: root epidermis
goid: TAIR:0000361
definition: epidermal layer of the root
definition_reference: ISBN:0471245208

term: root hair
goid: TAIR:0000256
definition: A type of trichome on root epidermis that is a simple extension of an epidermal cell and is concerned with absorption of soil solution.
definition_reference: ISBN:0471245208

term: root tip
goid: TAIR:0000251
definition: The portion of the root including the meristem and root cap.
definition_reference: TAIR:lr

term: rosette leaf
goid: TAIR:0000089
definition: Leaf that is part of phyllotactic spiral with little internode elongation between successive leaves. In Arabidopsis, vegetative development is characterized by the production of the rosette leaves. 
definition_reference: TAIR:KI
definition_reference: ISBN:0387940898

term: sclerenchyma
goid: TAIR:0000300
definition: A tissue composed of sclerenchyma cells
definition_reference: TAIR:KI

term: sclerenchyma cell
goid: TAIR:0000077
definition: Cell variable in form and size, being more or less thick, often lignified, secondary walls. Belongs to the category of subcells and may or may not be devoid of protoplast at maturity.
definition_reference: ISBN:0471245208

term: secretory cell
goid: TAIR:0000109
definition: Cell that produces secreted substances.
definition_reference: TAIR:KI

term: seed coat
goid: TAIR:0000265
definition: The outer coat of the seed derived from the integument or integuments.
definition_reference: ISBN:0471245208

term: seed coat epidermis
goid: TAIR:0000371
definition: the epidermal layer found on the outer surface of an organ
definition_reference: TAIR:lr

term: seed development
goid: TAIR:0000170
definition: The stages of seed development, from fertilization to the dry or quiescent state.
definition_reference: TAIR:ki

term: seed maturation
goid: TAIR:0000173
definition: Stage during which the seed storage products (storage proteins and lipids) are being accumulated, mainly in the cotyledons (which are already bended toward the chalazal end of the embryo sac). As a result, the body of the embryo increases in size while most of the endosperm is already depleted. Seed coat gradually changes from green to yellowish and finally to dark brown color.
definition_reference: TAIR:ki

term: seedling
goid: TAIR:0000027
definition:  A young plant that is partly dependent on substances of the maternal plant stored in the seed (especially the first leaves, called cotyledons). The plant always has embryological structures, including cotyledons, a primary root (the embryological root), and a primary shoot (the embryological stem)
definition_reference: URL:http //www.bbg.org/gar2/topics/botany/parts_grouping.html

term: sepal
goid: TAIR:0000125
definition: A unit of the calyx.
definition_reference: ISBN:0471245208

term: sepal epidermis
goid: TAIR:0000176
definition: the epidermal layer of the sepal.
definition_reference: TAIR:lr

term: septum
goid: TAIR:0000131
definition: any partition, whether within a cell, as in a septate fiber, or in an organ such as a fruit.
definition_reference: ISBN:0140514031

term: shoot
goid: TAIR:0000113
definition: The above ground portions, such as the stem and leaves, of a vascular plant.
definition_reference: ISBN:0471245208

term: sieve cell
goid: TAIR:0000285
definition: A type of sieve element that has relatively undifferentiated sieve areas (with narrow pores), rather uniform in structure on all walls; that is, there are no sieve plates. Typical of gymnosperms and lower vascular plants.
definition_reference: ISBN:0471245208

term: sieve element
goid: TAIR:0000286
definition: The cell in the phloem tissue concerned with mainly longitudinal conduction of food materials. Classified into sieve cell and sieve tube member.
definition_reference: ISBN:0471245208

term: sieve plate
goid: TAIR:0000287
definition: The part of the wall of a sieve element bearing one or more highly differentiated sieve areas. Typical of angiosperms.
definition_reference: ISBN:0471245208

term: sieve tube member
goid: TAIR:0000289
definition: One of the series of cellular components of a sieve tube. It shows a more or less pronounced differentiation between sieve plates (wide pores) and lateral sieve areas (narrow pores). Also sieve tube element and the obsolete sieve tube segment.
definition_reference: ISBN:0471245208

term: silica cell
goid: TAIR:0000101
definition: One of two types of short cells in the epidermis of grasses, silica cells have deposits of silica in them.
definition_reference: ISBN:0471245208

term: silique
goid: TAIR:0000208
definition: a dry dehiscent fruit common in Brassicas.
definition_reference: ISBN:0140514031

term: socket cell
goid: TAIR:0000115
definition: Cell that surround a trichome and provides support for the trichome.
definition_reference: ISBN:0471245208

term: somatic embryo
goid: TAIR:0000087
definition: An embryo arising from previously differentiated somatic cells in vitro, rather than from fused haploid gametes, i.e., zygote. 
definition_reference: TAIR:KI

term: specialization zone
goid: TAIR:0000348
definition: the portion of the root located behind the elongation zone containing cells that are differentiating into their final form and function.
definition_reference: ISBN:0879694289

term: sperm cell
goid: TAIR:0000084
definition: Male gamete, part of male germ unit.
definition_reference: TAIR:KI

term: spongy parenchyma
goid: TAIR:0000143
definition: Leaf mesophyll parenchyma with conspicuous intercellular spaces.
definition_reference: ISBN:0471245208

term: stage 1 flower
goid: TAIR:0000375
definition: stage of flower development marked by the emergence of the floral meristem on the flank of the inflorescence meristem.
definition_reference: ISBN:0387940898

term: stage 10 flower
goid: TAIR:0000384
definition: stage of flower development that begins when the petal height is level with the short stamens.
definition_reference: ISBN:0387940898

term: stage 11 flower
goid: TAIR:0000385
definition: stage of flower development that begins when the stigmatic papillae appear.
definition_reference: ISBN:0387940898

term: stage 12 flower
goid: TAIR:0000386
definition: stage of flower development that begins when the petal height is level with the long stamens.
definition_reference: ISBN:0387940898

term: stage 13 flower
goid: TAIR:0000388
definition: stage of flower development that begins when the floral bud opens and the petals are visible to the naked eye.
definition_reference: ISBN:0387940898

term: stage 14 flower
goid: TAIR:0000389
definition: Stage of floral development when long anthers extend above the stigma.
definition_reference: ISBN:0387940898

term: stage 15 flower
goid: TAIR:0000390
definition: Stage of floral development that begins when the stigma extends above the long anthers.
definition_reference: ISBN:0387940898

term: stage 16 flower
goid: TAIR:0000391
definition: Stage of floral development that begins when the petals and sepals begin to wither.
definition_reference: ISBN:0387940898

term: stage 17 flower
goid: TAIR:0000392
definition: Stage of floral development that begins when all of the floral organs have abscised and only the green silique remains.
definition_reference: ISBN:0387940898

term: stage 18 flower
goid: TAIR:0000422
definition: Stage of floral development that begins when the silique color changes from green to yellow.
definition_reference: ISBN:0387940898

term: stage 2 flower
goid: TAIR:0000376
definition: Stage of floral development that begins when the floral meristem becomes demarcated from the inflorescence meristem by a slight indentation.
definition_reference: ISBN:0387940898

term: stage 3 flower
goid: TAIR:0000377
definition: Stage of floral development that begins when the sepal primordia arise.
definition_reference: ISBN:038794898

term: stage 4 flower
goid: TAIR:0000378
definition: Stage of floral development that begins when the developing sepals overlie the floral meristem.
definition_reference: ISBN:0387940898

term: stage 5 flower
goid: TAIR:0000379
definition: Stage of floral development that begins when the petal and stamen primordia arise.
definition_reference: ISBN:038790898

term: stage 6 flower
goid: TAIR:0000380
definition: Stage of floral development that begins when the sepals enclose the floral bud.
definition_reference: ISBN:0387940898

term: stage 7 flower
goid: TAIR:0000381
definition: Stage of floral development that begins when the ling stamen primordia are stalked at the base.
definition_reference: ISBN:0387940898

term: stage 8 flower
goid: TAIR:0000382
definition: Stage of floral development that begins when the locules appear on the long stamens.
definition_reference: ISBN:0387940898

term: stage 9 flower
goid: TAIR:0000383
definition: Stage of floral development that begins when the petal primordia are stalked at the base.
definition_reference: ISBN:0387940898

term: stamen
goid: TAIR:0000152
definition: Floral organ producing the pollen and usually composed of anther and filament. The stamens together constitute the androecium.
definition_reference: ISBN:0471245208

term: starch sheath
goid: TAIR:0000002
definition: applied to the innermost regions (one or more cell layers)of the cortex when this region is characterized by conspicuous and rather stable accumulation of starch.
definition_reference: ISBN:047124520

term: starch sheath cell
goid: TAIR:0000020
definition: Cells characterized by conspicuous and rather stable accumulation of starch.
definition_reference: ISBN:044174520

term: stele
goid: TAIR:0000314
definition: a morphologic unit of the plant body comprising the vascular system and associated ground tissue (e.g. pericycle, interfascicular regions and pith).
definition_reference: ISBN:0471245208

term: stem epidermis
goid: TAIR:0000112
definition: epidermal layer of the stem
definition_reference: TAIR:lr

term: stigma
goid: TAIR:0000132
definition: The region of the carpel, in many taxa at the apex of the style, that serves as a surface upon which the pollen germinates.
definition_reference: ISBN:0471245208

term: stigma epidermis
goid: TAIR:0000164
definition: epidermal layer of the stigma.
definition_reference: TAIR:lr

term: stigmatic papillae
goid: TAIR:0000141
definition: ). A soft protuberance on an epidermal cell of the stigma.
definition_reference: ISBN:0471245208

term: stipule
goid: TAIR:0000215
definition: small appendages formed at the base of a leaf.
definition_reference: ISBN:0716719460

term: stomatal complex
goid: TAIR:0000281
definition: An opening in the epidermis of leaves and stems bordered by two guard cells and serving in gas exchange.
definition_reference: ISBN:0471245208

term: stomium
goid: TAIR:0000157
definition: A fissure or pore in the anther lobe through which the pollen is released. Its formation is a type of dehiscence.
definition_reference: ISBN:0471245208

term: style
goid: TAIR:0000133
definition: Extension of the top of the ovary, usually columnar, through which the pollen tube grows.
definition_reference: ISBN:0471245208

term: style epidermis
goid: TAIR:0000165
definition: epidermal layer of the style.
definition_reference: TAIR:lr

term: style parenchyma
goid: TAIR:0000307
definition: parenchyma tissues of the style.
definition_reference: TAIR:lr

term: subsidiary cell
goid: TAIR:0000284
definition: an epidermal cell associated with a stoma and at least morphologically distinguishable from the epidermal cells composing the groundmass of the tissue.
definition_reference: ISBN:047124520

term: suspensor
goid: TAIR:0000175
definition: An extension at the base of the embryo that anchors the embryo in the embryo sac and pushes it into the endosperm.
definition_reference: ISBN:0471245208

term: synergid
goid: TAIR:0000191
definition: cells in the micropylar end of the embryo sac associated with the egg in the egg apparatus of angiosperms. Play a vital role in fertilization.
definition_reference: ISBN:047125208

term: tapetum
goid: TAIR:0000159
definition: In anther, a layer of cells lining the locule and absorbed as the pollen grains mature. 
definition_reference: ISBN:047125208

term: tissues and tissue systems
goid: TAIR:0000140
definition: Tissues are a group of cells organized into a structural and functional unit. Component cells may be alike (simple tissue) or varied (complex tissue). Tissue systems are tissue or tissues in a plant or plant organ structurally and functionally organized into a unit. Commonly three tissue systems are recognized, dermal, vascular, and fundamental (ground tissue system).
definition_reference: ISBN:0471245208

term: torpedo stage
goid: TAIR:0000187
definition: During this stage the embryo elongates into the cellular endosperm and the internal layers of the hypocotyl and radicle differentiate to form the vascular tissue. Lipid deposition into the cotyledons begins at this stage. Organelle differentiation occurs leading to greening of the embryo.
definition_reference: ISBN:0387940898

term: tracheary element
goid: TAIR:0000290
definition: general term for a water conducting cell, tracheid or vessel member.
definition_reference: ISBN:0471245208

term: tracheid
goid: TAIR:0000301
definition: A tracheary element of the xylem that has no perforations, as contrasted with a vessel member. May occur in primary and in secondary xylem. May have any kind of secondary wall thickening found in tracheary elements.
definition_reference: ISBN:0471245208

term: transfer cell
goid: TAIR:0000078
definition: Parenchyma cell with the wall ingrowth (or ivaginations) that increase the surface of the plasmalemma. Appears to be specialized for short-distance transfer of solutes.
definition_reference: ISBN:0471245208

term: transmitting tract
goid: TAIR:0000134
definition: The tissue in the style of a flower through which the pollen tube grows between the stigma and the ovarian cavity. Also called pollen conducting tissue.
definition_reference: ISBN:0471245208

term: triangle stage
goid: TAIR:0000029
definition: A transient stage between the late globular and heart stage when the first cell divisions of the cotyledon primordia begin and cell elongation starts in the procambium.
definition_reference: ISBN:0387940898

term: trichoblast
goid: TAIR:0000262
definition: Commonly used for a cell in root epidermis that gives rise to a root hair. The daughter cell produced by the asymmetric division of a root epidermal cell that gives rise to a root hair.
definition_reference: ISBN:0471245208

term: trichome
goid: TAIR:0000282
definition: An outgrowth from the epidermis. Trichomes vary in size and complexity and include hairs, scales, and other structures and may be glandular. In Arabidopsis, patterning of trichome development is not random but does not appear to be lineage-based like stomata.
definition_reference: ISBN:0471245208

term: two-celled stage
goid: TAIR:0000177
definition: The embryo after the first mitotic division that produces a smaller apical cell and larger basal cell. The basal cell gives rise to the radicle and the suspensor. The apical cell gives rise all of the embryo except the root.
definition_reference: ISBN:0387940898

term: upper tier
goid: TAIR:0000354
definition: In an eight celled embryo, the upper four cells formed by mitotic division of the apical cell. These cells will give rise to the apical meristem and cotyledons.
definition_reference: ISBN:089694269

term: vascular bundle
goid: TAIR:0000362
definition: A strandline part of the vascular system composed of xylem and phloem.
definition_reference: ISBN:0471245208

term: vascular cambium
goid: TAIR:0000356
definition: Lateral meristem that forms the secondary vascular tissues, secondary phloem and secondary xylem, in stem and root. I located between those two tissues and, by periclinal divisions, gives off cells toward both tissues.
definition_reference: ISBN:047125208

term: vascular cylinder
goid: TAIR:0000093
definition: Vascular region of the axis.
definition_reference: ISBN:0471245208

term: vascular system
goid: TAIR:0000270
definition: The total of the vascular tissues in their specific arrangement in a plant or plant organ.
definition_reference: ISBN:047125208

term: vascular tissue
goid: TAIR:0000327
definition: A general term referring to either or both vascular tissues, xylem and phloem.
definition_reference: ISBN:047125208

term: vegetative
goid: TAIR:0000305
definition: stages of development that occur  from seed germination up to flowering
definition_reference: TAIR:lr

term: vegetative cell
goid: TAIR:0000169
definition: Cell type formed after the first mitotic division of the microgametophye, The nucleus of this cell migrates to the tip of the pollen tube after germination and disintegrates when the pollen tube penetrates the nucellus.
definition_reference: TAIR:lr
definition_reference: ISBN:0140514031

term: vegetative meristem
goid: TAIR:0000033
definition: A shoot meristem that gives rise to only non-reproductive organs and tissues.
definition_reference: TAIR:lr

term: visible flower buds
goid: TAIR:0000420
definition: Whole plant developmental stage at which the first flower buds become visible to the naked eye
definition_reference: PMID:11449047

term: xylem
goid: TAIR:0000271
definition: The principal water-conducting tissue in vascular plants characterized by the presence of tracheary elements. The xylem may also serve as a supporting tissue, especially the secondary xylem (wood).
definition_reference: ISBN:047125208

term: xylem element
goid: TAIR:0000273
definition: Cells composing the xylem
definition_reference: ISBN:0471245208

term: xylem fiber cell
goid: TAIR:0000274
definition: A fiber of the xylem tissue, Two types are recognized in the secondary xylem: fiber tracheids and libriform fibers.
definition_reference: ISBN:0471245208

term: xylem initial
goid: TAIR:0000275
definition: A cambial cell on the xylem side of the cambial zone that is the source of one or more cells arising by periclinal divisions and differentiating into xylem elements either with or without additional divisions in various planes. Sometimes called xylem mother cell.
definition_reference: ISBN:047125208

term: xylem initial
goid: TAIR:0000357
definition: A cambial cell on the xylem side of the cambial zone that is the source of one or more cells arising by periclinal divisions and differentiating into xylem elements either with or without additional divisions in various planes. 
definition_reference: ISBN:0471245208

term: xylem parenchyma
goid: TAIR:0000358
definition: parenchyma tissue of the xylem
definition_reference: TAIR:lr

term: xylem/symplast boundary
goid: TAIR:0000091
definition: A boundary between non-living, apoplastic water transport system and adjacent parenchyma cells in the root, stems and leaves.
definition_reference: TAIR:KI

term: zygote
goid: TAIR:0000097
definition: One cell stage that takes place following the fertilization, (i.e., fusion of sperm cell nucleus and egg cell resulting in a diploid cell) and before the first mitotic cell division. It marks the beginning of sporophytic generation in the life cycle of the Angiosperms.
definition_reference: TAIR:KI

term: zygote
goid: TAIR:0000423
definition: Diploid cell produced by the fusion of sperm cell nucleus and egg cell in the process of double fertilization.
definition_reference: TAIR:KI

term: zygotic embryo
goid: TAIR:0000088
definition: A product of double fertilization that represents the next (sporophytic) generation
definition_reference: TAIR:KI