Yamasaki S, Fujii N, Takahashi H
Institute of Genetic Ecology, Tohoku University, Sendai, Japan.
Plant Cell Physiol. 2000 May;41(5):608-16. doi: 10.1093/pcp/41.5.608.
It has been reported that ethylene production by cucumber plants is strongly related to the sex expression of their flowers. It has also been shown that both CS-ACS2 gene expression and ethylene evolution are much greater in gynoecious cucumber plants than monoecious ones. To investigate the action mechanism of ethylene in the induction of femaleness of cucumber flowers, we isolated three ethylene-receptor-related genes, CS-ETR1, CS-ETR2 and CS-ERS, from cucumber (Cucumis sativus L.) plants. Of these three genes, CS-ETR2 and CS-ERS mRNA accumulated more substantially in the shoot apices of the gynoecious cucumber than those of the monoecious one. Their expression patterns correlated with the expression of the CS-ACS2 gene and with ethylene evolution in the shoot apices of the two types of cucumber plants. Accumulation of CS-ETR2 and CS-ERS mRNA was significantly elevated by the application of Ethrel, an ethylene-releasing agent, to the shoot apices of monoecious cucumber plants. In contrast, the accumulation of their transcripts was lowered when aminoethoxyvinyl glycine (AVG), an inhibitor of ethylene biosynthesis, was applied to the shoot apices of gynoecious cucumber plants. Thus, the expression of CS-ETR2 and CS-ERS is, at least in part, regulated by ethylene. The greater accumulation of CS-ETR2 and CS-ERS mRNA in gynoecious cucumber plants may be due to the higher level of endogenous ethylene, which plays a role in the development of female flowers.
据报道，黄瓜植株产生乙烯与花的性别表达密切相关。研究还表明，雌性黄瓜植株中CS - ACS2基因的表达和乙烯释放量均比雌雄同株的黄瓜植株高得多。为了研究乙烯诱导黄瓜花雌性化的作用机制，我们从黄瓜（Cucumis sativus L.）植株中分离出三个乙烯受体相关基因，即CS - ETR1、CS - ETR2和CS - ERS。在这三个基因中，CS - ETR2和CS - ERS的mRNA在雌性黄瓜植株茎尖中的积累量比雌雄同株的黄瓜植株更多。它们的表达模式与两种黄瓜植株茎尖中CS - ACS2基因的表达以及乙烯释放相关。通过向雌雄同株黄瓜植株的茎尖施用乙烯释放剂乙烯利，CS - ETR2和CS - ERS mRNA的积累量显著增加。相反，当向雌性黄瓜植株的茎尖施用乙烯生物合成抑制剂氨基乙氧基乙烯基甘氨酸（AVG）时，它们转录本的积累量降低。因此，CS - ETR2和CS - ERS的表达至少部分受乙烯调节。雌性黄瓜植株中CS - ETR2和CS - ERS mRNA积累量较多可能是由于内源性乙烯水平较高，其在雌花发育中起作用。
