Proteomic Analysis Of Fertility Alternation In The Thermo-Sensitive Sterile Rice

In thermo-sensitive genic male sterile rice (TGMS), there is one special species, which displayed male sterile at low temperatures but fertility at high temperatures. The mechanism of fertility alteration in these TGMS lines is still unclear. With TGMS go543s rice as materials, this study utilized morphological, cytological and proteomics to investigate and compare the change of morphology, cellular structure and proteins during spikelet development at high (34℃) and low (23℃) temperatures within the sensitive periods of fertility alternation (from Ⅳ stage to Ⅵ stage). It was aimed to identity some key factors potentially involved in fertility formation of go543s.The content of this study includes:(1) Morphological and cellular observation of the rice spikelet and anther;(2) Optimization the proteomic approach for research materials(3) Investigate the proteomic change during the fertility alternation stage for go543s.Compared with sterile spikelet, fertile spikelet, was plump and had deep colour. In addition, fertile anther was full of mature pollen grains which could be stained by K2I and the tapetum of it was degenerated at the late of spikelet development However, the tapetum of sterile anther could not be degenerated and the pollen grains in the anther were abnormally developed with an irregular appearance and could not be stained by K2I. The appropriate approaches for proteomic analysis were to extract spikelet proteins by saturation phenol, use the IPG strip of pH 5-8 and load 450 μg proteins with adding space gel to SDS-PAGE.A total of 104 and 87 spots were identified to change in abundance (≥ two fold, P<0.05) during spikelet development at the fertile and sterile temperatures, respectively. At the fertile temperature,82 protein spots increased, and 22 protein spots decreased in abundance during spikelet development. Among those spots with higher abundance in fertile spikelet,44% belong to the metabolism, and 18% and 16% were involved in cell defense and rescue and energy, respectively. At the sterile temperature,65 and 22 protein spots showed a increase and decrease in abundance, respectively, during spikelet development. In the increasing pattern, the proteins involved in metabolism accounted for a largest percentage,45%, while those involved in cell defense and rescue and energy were 20% and 15%, respectively. Twenty eight protein spots were found to accumulate in higher abundance in fertile spikelet than sterile spikelet. These proteins were involved in metabolism, cell defense and rescue, protein folding, storage, energy and signal transduction. Some of these proteins were directly or indirectly related to rice fertility, such as Beta-galactosidase 1,60 kDa chaperonin alpha subunit, glutaredoxin, Flavone 3’-O-methyltransferase 1, EF hand family protein and ALDH.Through the functional analysis of these proteins,we conclude that "timing" of degeneration for tapetum, development of pollen tube, and energy play a potential crucial role in go543s fertility formation. Our results have provided some new information that will help us to understand the mechanism of fertility alteration further.