Poster: Reproductive Development

Abs # 489: Regulatory mechanisms controlling flowering plant male gametic cell specific gene expression

Presenter:	Singh, Mohan M, mohan@unimelb.edu.au
Authors	Singh, Mohan M (A)   Bhalla, Prem L (A)   Singh, Manjit  (A)   Okada, Takashi  (A)   Haerizadeh, Farzad  (A)
Affiliations:	(A): University of Melbourne

Sperm cells, the male gametes of flowering plants are produced by mitotic division of generative cell that takes place during either pollen maturation or pollen tube growth in pistil. This highly asymmetric mitotic division marks the generative cell for a developmental fate very different from that of the vegetative cell. While the vegetative cell takes part in the process of fertilization through pollen germination and pollen tube growth, the generative cell divides to form sperm cells. Previously, we have provided the first evidence of generative cell specific genes in flowering plants (PNAS, 1999, 96, 2554-2558). We have now addressed regulatory mechanisms controlling generative/sperm cell specific genes. The male gametic cell specific gene expression appears to be controlled via selective repression of transcription in vegetative cell of pollen and other plant tissues. This is in contrast to other reported pollen specific (vegetative cell) genes, in which pollen specificity is achieved, in large part by specifically expressed enhancers. Identification of the controlling elements of generative specific genes should provide novel insights into flowering plant male gamete specific gene expression. Additionally these can be used as a novel tools in molecular analyses and experimental manipulation of fertilization in flowering plants.