DELLA activity is required for successful pollen development in the Columbia ecotype of Arabidopsis.
Bottom Line: Loss of DELLA activity in the monocot rice (Oryza sativa) causes complete male sterility, but not in the dicot model Arabidopsis (Arabidopsis thaliana) ecotype Landsberg erecta (Ler), in which DELLA function has been studied most extensively, leading to the assumption that DELLA activity is not essential for Arabidopsis pollen development.Col-0 rga gai mutants, in contrast with the equivalent Ler phenotype, were entirely male sterile, caused by post-meiotic defects in pollen development, which were rescued by the reintroduction of DELLA into either the tapetum or developing pollen.We conclude that DELLA activity is essential for Arabidopsis pollen development.
Affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.Show MeSH
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Mentions: Anther and pollen development in rga-28 gai-td1 (Col-0) were examined microscopically to identify the cause of pollen lethality. Pollen mother cells (PMCs) were visible in both wild-type and mutant anthers (Fig.4a,b). Successful tetrad formation and microspore release were observed in wild-type anthers (Fig.4c,m), whereas, by contrast, although some tetrads in rga-28 gai-td1 anthers apparently progressed successfully to the free microspore stage (Fig.4n), abnormal meiotic products were frequently observed (Figs4d, S6). Post-meiotic rga-28 gai-td1 pollen development was also abnormal: wild-type microspores progressed through pollen mitosis to maturity (Fig.4o,q,s,u), but microspore nuclear polarization before pollen mitosis was not observed in rga-28 gai-td1 (Fig.4p), and microspores subsequently degenerated (Fig.4r,t).
Affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.