The tomato ethylene receptors NR and LeETR4 are negative regulators of ethylene response and exhibit functional compensation within a multigene family.
The tomato ethylene receptors NR and LeETR4 are negative regulators of ethylene response and exhibit functional compensation within a multigene family.
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DOI：
10.1073/pnas.090550597
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发表时间：
2000-05
影响因子：
11.1
通讯作者：
D. Tieman;Mark G. Taylor;Joseph A. Ciardi;H. Klee
中科院分区：
文献类型：
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作者：
D. Tieman;Mark G. Taylor;Joseph A. Ciardi;H. Klee
植物激素乙烯参与许多发育过程，包括果实成熟、脱落、衰老和叶上生。番茄含有乙烯受体家族，分别命名为 LeETR1、LeETR2、NR、LeETR4 和 LeETR5，与拟南芥 ETR1 乙烯受体具有同源性。 LeETR4基因表达减少的转基因植物表现出极端乙烯敏感性的多种症状，包括严重上性、花衰老增强和果实成熟加速。因此，LeETR4 是乙烯反应的负调节因子。该单一基因表达的减少会影响番茄的多个发育过程，而在拟南芥中，必须使多个乙烯受体失活才能增加乙烯反应。 NR mRNA 水平降低的转基因系表现出正常的乙烯敏感性，但 LeETR4 mRNA 水平升高，表明 LeETR4 对 NR 表达降低的功能补偿。 LeETR4基因表达降低的品系中NR的过表达消除了乙烯敏感表型，表明尽管结构上存在显着差异，但这些乙烯受体在功能上是冗余的。
The plant hormone ethylene is involved in many developmental processes, including fruit ripening, abscission, senescence, and leaf epinasty. Tomato contains a family of ethylene receptors, designated LeETR1, LeETR2, NR, LeETR4, and LeETR5, with homology to the Arabidopsis ETR1 ethylene receptor. Transgenic plants with reduced LeETR4 gene expression display multiple symptoms of extreme ethylene sensitivity, including severe epinasty, enhanced flower senescence, and accelerated fruit ripening. Therefore, LeETR4 is a negative regulator of ethylene responses. Reduced expression of this single gene affects multiple developmental processes in tomato, whereas in Arabidopsis multiple ethylene receptors must be inactivated to increase ethylene response. Transgenic lines with reduced NR mRNA levels exhibit normal ethylene sensitivity but elevated levels of LeETR4 mRNA, indicating a functional compensation of LeETR4 for reduced NR expression. Overexpression of NR in lines with lowered LeETR4 gene expression eliminates the ethylene-sensitive phenotype, indicating that despite marked differences in structure these ethylene receptors are functionally redundant.