Anther Development and Stamen/Pollen Biology (BIO 50)

Vocabulary flashcards covering key terms related to anther development, stamen structure, floral meristem identity, pollen formation, dehiscence, and related genes.

Stamen

The male reproductive part of a flower, consisting of the filament and the anther.

Anther

The part of the stamen where pollen grains are produced.

Filament

The stalk of the stamen that positions the anther for pollination.

Pollen sacs

Locules within the anther that contain developing pollen grains.

Tapetum

Innermost layer of the anther wall that nourishes developing pollen and supplies materials for the pollen wall; comes in secretory or plasmodial types.

Epidermis

The outermost cell layer of the anther wall that provides protection and supports dehiscence.

Locular space

The cavity within each anther locule that houses developing pollen.

Floral primordia

The initial tissue that differentiates to form the floral organs.

Floral transition

Genetic switch from vegetative growth to the floral (flower) state.

MADS (MADS-box)

A family of transcription factors that regulate floral organ identity; central to the ABCDE model.

Floral homeotic factors

Genes (A, B, C, D, E classes) that specify organ identity in each whorl of the flower.

Sepal

The outermost floral organ, defined by specific combinations of floral homeotic genes.

Petal

The second whorl floral organ, often defined by A and B class genes.

Carpel

The innermost floral whorl, the female reproductive organ, defined by C, D, and E class genes.

Ovule

Structure inside the carpel that develops into the seed after fertilization.

Anther primordium

Early anther-forming tissue arising from the floral meristem.

Anther differentiation

Process by which anther primordium forms distinct tissues including sporogenous tissue and the anther wall.

Microsporogenesis

Production of microspores (pollen precursors) via meiosis within the anther.

Anther dehiscence

Opening of the anther to release mature pollen.

Periclinal division

Division of a cell layer parallel to the surface, forming archesporial cells and other layers.

Archesporial cells (AR cells)

Reproductive cells formed from the L2 layer that give rise to sporogenous tissue and anther walls.

Sporogenous tissue

Tissue that contains cells which become pollen mother cells and microspores.

Pollen mother cells (PMCs)

Diploid cells in the anther that undergo meiosis to form microspores.

Primary parietal cells (PP)

Inner wall-layer precursors derived from L2 that form the endothecium, middle layer, and tapetum.

Secondary parietal cells (SP)

Derived from primary parietal cells and give rise to endothecium, middle layer, and tapetum.

Endothecium

A lignified anther wall layer that contributes to dehiscence.

Middle layer

Anther wall layer between endothecium and tapetum involved in structure and dehiscence.

Secretory (glandular) tapetum

Tapetum type that remains in the locule and secretes pollen-wall materials before breaking down.

Plasmodial (amoeboid) tapetum

Tapetum type where cell walls break down to form a multinucleate plasmodium that nourishes pollen.

Tetrad

Group of four microspores formed after meiosis, initially attached.

Bicellular pollen

A pollen grain containing two cells (vegetative and generative) at the bicellular stage.

Free microspore

Individual microspores released from the tetrad.

Exine

The outer pollen-wall layer made mainly of sporopollenin.

Intine

The inner pollen-wall layer under the exine.

Callase

Enzyme secreted by the tapetum that digests callose to release microspores from the tetrad.

Pollen grain

Mature male gametophyte that contains the vegetative cell and one or two sperm cells.

Generative cell

Cell inside the pollen grain that divides to form sperm cells.

Vegetative cell

Pollen grain cell that grows the pollen tube during germination.

Pollen tube

Extends from the pollen grain to deliver sperm cells to the ovule.

Sperm cells

Male gametes produced by the generative cell that fertilize the ovule.

Introrse

Pollen release toward the center of the flower.

Extrorse

Pollen release away from the center of the flower.

Longitudinal dehiscence

Anther opens along its long axis to release pollen.

Poricidal dehiscence

Pollen released through a terminal pore rather than a slit.

Valvular dehiscence

Pollen released through a pore covered by a flap of tissue.

Stomium

The final breakage site on the anther wall during dehiscence.

Connective tissue

The tissue between the two anther lobes that supports and connects to the filament.

Monocot vs Dicot

Two major groups of flowering plants with differences in anther structure and development.

DYT1

Gene; ortholog involved in early tapetum development.

TDF1

Gene; ortholog involved in early tapetum development.

AMS

Gene; ortholog involved in tapetum development.

MS188 (MYB80)

Gene; tapetum PCD and exine/pollen-wall formation.

MS1

Gene; tapetum PCD and exine formation.

OsUDT1

Rice ortholog involved in tapetum development.

ZmMs32

Zea mays gene involved in sporopollenin synthesis.

ZmMs9

Maize gene involved in sporopollenin synthesis.

ZmbHLH51

Maize bHLH transcription factor important for tapetum and pollen development.

PKSA

Gene encoding a polyketide synthase family member involved in sporopollenin synthesis.

PKSB

Gene encoding an acyltransferase involved in sporopollenin synthesis.

ABCG26

ABC transporter involved in pollen coat formation/transport.

TEK

Gene involved in pollen coat synthesis.