Genetic Regulation of Ethylene Dosage for Cucumber Fruit Elongation
Genetic Regulation of Ethylene Dosage for Cucumber Fruit Elongation
复制标题
乙烯用量对黄瓜果实伸长的遗传调控
DOI：
10.1105/tpc.18.00957
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发表时间：
2019-05-01
期刊：
影响因子：
11.6
通讯作者：
Yang, Xueyong
中科院分区：
文献类型：
--
作者：
Xin, Tongxu;Zhang, Zhen;Yang, Xueyong
植物器官的生长发育是由生长刺激和生长抑制之间的微妙平衡决定的。果实大小和形状是影响产量和市场价值的重要品质性状；然而，调节果实生长平衡以达到最终大小和形状的潜在机制尚不清楚。在这里，我们报告了一个通过微调乙烯稳态来控制黄瓜（Cucumis sativus）果实伸长的机制模型。我们发现了一个黄瓜突变体，由于细胞分裂受到抑制而结出短果实。SF1 （Short Fruit 1）编码葫芦特有的环型E3连接酶，突变导致其自身泛素化和降解增强，但积累了1-氨基环丙烷-1-羧酸合成酶2(1-氨基环丙烷-1-羧酸合成酶2)，这是一种乙烯生物合成的限速酶。乙烯的过量产生导致了sf1的短果表型。ACS2功能障碍导致乙烯产量减少，但仍抑制细胞分裂和缩短果实，表明乙烯仍然是基生果伸长所必需的。SF1泛素化并降解自身和ACS2，以控制乙烯合成，对细胞分裂和果实伸长产生剂量依赖效应。我们的研究结果揭示了乙烯用量对发育果实细胞分裂控制的机制。
Plant organ growth and development are determined by a subtle balance between growth stimulation and inhibition. Fruit size and shape are important quality traits influencing yield and market value; however, the underlying mechanism regulating the balance of fruit growth to achieve final size and shape is not well understood. Here, we report a mechanistic model that governs cucumber (Cucumis sativus) fruit elongation through fine-tuning of ethylene homeostasis. We identified a cucumber mutant that bears short fruits owing to repressed cell division. SF1 (Short Fruit 1) encodes a cucurbit-specific RING-type E3 ligase, and the mutation resulted in its enhanced self-ubiquitination and degradation, but accumulation of ACS2 (1-aminocyclopropane-1-carboxylate synthase 2), a rate-limiting enzyme for ethylene biosynthesis. The overproduction of ethylene contributes to the short-fruit phenotype of sf1. Dysfunction of ACS2 resulted in reduced ethylene production, but still repressed cell division and shorter fruit, suggesting that ethylene is still required for basal fruit elongation. SF1 ubiquitinates and degrades both itself and ACS2 to control ethylene synthesis for dose-dependent effect on cell division and fruit elongation. Our findings reveal the mechanism by which ethylene dosage is regulated for the control of cell division in developing fruit.