深圳大学：《植物生理学 Plant Physiology》课程教学资源（PPT课件）Chapter11 植物的生殖生理 Reproduction Physiology

chapter 11 Reproduction Physiology

chapter 11 Reproduction Physiology

Plant reproductive physiology

Plant reproductive physiology

Objectives: to understand How flowering is induced How flowering is controlled (abc model a The structure offlowers and their reproductive components Pollination

▪ How flowering is induced ▪ How flowering is controlled (ABC model) ▪ The structure of flowers and their reproductive components ▪ Pollination Objectives; to understand

Sexual reproduction In Angiosperms. sexual reproduction is based on the production of gametes配子( egg and sperm)by meIosis减数分裂 Male gametes are Female gametes Both male and produced as are produced in emale gametes pollen花粉 grains the ovule胚珠 are produced in the flower

Female gametes are produced in the ovule胚珠 Male gametes are produced as pollen花粉grains Sexual reproduction In Angiosperms, sexual reproduction is based on the production of gametes 配子 (egg and sperm) by meiosis 减数分裂. Both male and female gametes are produced in the flower

Change in function of apica/ meristem分生组织 vegetative apex LOwering shoot apex flowering is initiated by the changes of a vegetative shoot apex shoot apical Floral bud Floral 顶端 to a flowering meristem tesf Shoot apical shoot apex

Change in function of apical meristem分生组织 Flowering is initiated by the changes of a vegetative shoot apex 顶端 to a flowering shoot apex

Flower development Induction Signal Competent: Determined xpressed Able to respond in Able to follow same The apical expected manner developmental meristem when given the Photoperiod program even after Hormones undergoes appropriate removal from its morphogenesis developmental normal position sig lant Vegetative growth Flowers A simplified model for floral evocation at the respond to a floral stimulus (induction)by becoming flo shoot apex in which the cells of the vegetative meristem rally determined ( committed to producing a flower). The acquire new developmental fates. To initiate floral develop- determined state is usually expressed, but this may require ment, the cells of the meristem must first become compe- an additional signal (After McDaniel et al. 1992. tent. A competent vegetative meristem is one that can

Flower development

What induces the apex to change from a Two factors that can induce flowering 1. Cold temperature(vernalization). 2. Daylength(photoperiodism)

Two factors that can induce flowering: 1. Cold temperature (vernalization). 2. Daylength (photoperiodism). What induces the apex to change from a vegetative to a flowering state?

Some plants flower in response to cold RIation refers specifica by a period of low temperature. Winter annual (Winter cereal) Winter strains planted in the spring would normally fail to flower Biennials. Biennials are normall flower and die in the second season, again following an overwintering cold treatment In either case. the cold treatment appears to be effective only in the FR 5AM meristematic zones of the shoot pex

Some plants flower in response to cold Vernalization refers specifically to the promotion of flowering by a period of low temperature. Winter annual (Winter cereal): Winter strains planted in the spring would normally fail to flower Biennials:Biennials are normally flower and die in the second season, again following an overwintering cold treatment. In either case, the cold treatment appears to be effective only in the meristematic zones of the shoot apex

Vernalization and de-vernalization Cold Cold temperature Precursor temperature Intermediate Final product product 25~40℃or impropriate daylength treat Degradation It is the shoot apex that receives the signal of De-vernalization cold temperature Vernalization can be removed by other treatments, this phenomena is called de-vernalization

It is the shoot apex that receives the signal of cold temperature. De-vernalization 25~40℃ or impropriate daylength Vernalization can be removed by other treatments, this phenomena is called de-vernalization. Intermediate product Precursor Final product Cold temperature Degradation Vernalization and de-vernalization Cold temperature

Mechanism of vernalization During vernalizaiton Vernalin New proteins(anti-sense inhibition) Change gene expression by demethylation

Mechanism of vernalization During vernalizaiton Vernalin ? New proteins (anti-sense inhibition). Change gene expression by demethylation