玉米S型细胞质雄性不育与恢复花粉中基因表达差异分析

以近等基因系S-Mo17Rf3Rf3和S-Mo17rf3rf3为材料,通过抑制消减杂交对S(Rf3)和S(rf3)花粉中差异表达的基因进行了研究.结果表明,玉米(Zea mays L.)S(Rf3)和S(rf3)花粉中存在与信号传导、膜系统形成、花粉的成熟以及抗细胞衰老等细胞和生理活动相关的基因表达的差异,但没有发现参与糖代谢、淀粉合成及其转运相关基因的表达差异.O-乙酰半乳糖胺转移酶(O-linked GlcNAc transferase,OGT)基因在Rf3花粉中表达累积.依据OGT基因的功能及其在玉米不同育性花粉中的表达模式,推测OGT受糖类物质诱导表达并与S(Rf3)配子的育性恢复有关.这一假说还有待进一步实验证实.

A Study on Different Genes Expressed in Maize (Zea mays L.) Male Sterile S-(rf3) and Restored S-(Rf3) Pollen

To investigate the mechanism of Rf3/rf3 to pollen fertility, a set of near isogenic line, S-MO17~Rf3Rf3 and S-Mo17~rf3rf3,was used to explore different genes expressed in S(Rf3)and S(rf3)via suppression subtractive hybridization(SSH).The results showed that many differentially expressed genes were identified in both microspore S(Rf3)and S(rf3). These differentially expressed genes were involved in different physiology processes, such as signal conduction, cell membrane formation, pollen maturation and anti-apoptotic, but genes associated with carbohydrate metabolism, starch biosynthesis and transporter had not been identified. The gene encoding O-linked GlcNAc transferase(OGT) showed high mRNA abundance in S(Rf3) pollen, but not in S(rf3). Based on the expression pattern and function of OGT,it was hypothesized that OGT gene expression may be induced by carbohydrate in S(Rf3)pollen,then OGT modify targeting protein in nucleolus,these modified protein as a signal to trigger subsequently genes expression which involve into signal conduction, cell membrane formation, pollen maturation and anti-apoptotic. In cytoplasm, TPR domain of OGT interacts specifically with targeting proteins translated in mitochondrion in order to eliminate disadvantage effect of S type cytoplasm. The experiment validation on the hypothesis is still retained.