Correlation between development of female flower buds and expression of the CS-ACS2 gene in cucumber plants
Correlation between development of female flower buds and expression of the CS-ACS2 gene in cucumber plants
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DOI：
10.1093/jxb/erm141
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发表时间：
2007-09-01
影响因子：
6.9
通讯作者：
Takahashi, Hideyuki
中科院分区：
文献类型：
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作者：
Saito, Sayoko;Fujii, Nobuharu;Takahashi, Hideyuki
乙烯在黄瓜花性别决定中起着关键作用。雌雄同株黄瓜枝条比雌雄同株黄瓜枝条产生更多的乙烯。由于雌雄同株黄瓜在顶端同时产生雄花和雌花，而且雄花和雌花的相对比例因生长条件的不同而不同，因此出现了这样的问题：每个花蕾中乙烯生物合成的调节是否决定了花的性别。因此，研究了1-氨基环丙烷-1-羧酸合成酶基因CS-ACS2在不同发育阶段黄瓜花蕾中的表达。结果表明，CS-ACS2mRNA在两性花蕾雌蕊原基下方开始积累，但在雌蕊原基形成之前未检测到。在决定发育为雌花的花蕾中，CS-ACS2 mRNA继续积累在发育中的子房中央区域，在那里形成胚珠和胎座。在只产生雌花的雌雄异株黄瓜植株中，CS-ACS2 mRNA在两性时期和发育后期的所有花蕾中都有积累。在雌雄同株黄瓜中，一些节上的花蕾积累了CS-ACS2mRNA，而另一些节上的花芽则不积累。雌雄同株黄瓜的雄花和雌花比例因生长条件的不同而不同，但与花蕾中CS-ACS2 mRNA积累的变化有关。这些结果表明，CS-ACS2介导的乙烯生物合成与雌花的分化和发育有关。
Ethylene plays a key role in sex determination of cucumber flowers. Gynoecious cucumber shoots produce more ethylene than monoecious shoots. Because monoecious cucumbers produce both male and female flower buds in the shoot apex and because the relative proportions of male and female flowers vary due to growing conditions, the question arises as to whether the regulation of ethylene biosynthesis in each flower bud determines the sex of the flower. Therefore, the expression of a 1-aminocyclopropane-1-carboxylic acid synthase gene, CS-ACS2, was examined in cucumber flower buds at different stages of development. The results revealed that CS-ACS2 mRNA began to accumulate just beneath the pistil primordia of flower buds at the bisexual stage, but was not detected prior to the formation of the pistil primordia. In buds determined to develop as female flowers, CS-ACS2 mRNA continued to accumulate in the central region of the developing ovary where ovules and placenta form. In gynoecious cucumber plants that produce only female flowers, accumulation of CS-ACS2 mRNA was detected in all flower buds at the bisexual stage and at later developmental stages. In monoecious cucumber, flower buds situated on some nodes accumulated CS-ACS2 mRNA, but others did not. The proportion of male and female flowers in monoecious cucumbers varied depending on the growth conditions, but was correlated with changes in accumulation of CS-ACS2 mRNA in flower buds. These results demonstrate that CS-ACS2-mediated biosynthesis of ethylene in individual flower buds is associated with the differentiation and development of female flowers.