Материал из Антэкология /// Anthecology
New Perspectives in Pollen Biology and Fertilization
The reproductive biology of flowering plants is one of the most rapidly developing fields in plant science, due largely to the introduction of new molecular and computer technology. Today, the techniques of cell biology have new implications for plant reproductive success. This success can be estimated using measurements of pollen quantity and quality, pollen germination and tube growth, and successful fertilization. The complex array of interrelated processes constituting reproductive success is a focus for plant biologists who need to understand, modify and exploit them for plant improvement. The success of fertilization is reviewed in terms of (1) differential gene expression in pistil and pollen, and (2) effectiveness of the gametes. On the female side, potential genes of interest include those regulating stigma receptivity, self-incompatibility and ovule viability. On the male side, interest centres on molecular analysis of certain pollen-specific genes which affect male transmission at fertilization. Experimental analysis of the effectiveness of the male and female gametes is being approached in two distinct ways: (1) analysis of their nature and organization using image analysis combined with interactive computer graphics, and (2) isolation of the gametes using cell fractionation technology. Examples of these approaches are given for sperm cell biology, where there are two important questions to be answered: (1) what is the organization of the pair of sperm cells and their delivery system within the pollen tube? and (2) is there specific recognition between the sperm cells and the female gametes — the egg and central cell?