Tieman D M, Ciardi J A, Taylor M G, Klee H J
PO Box 110690, Horticultural Sciences Department, University of Florida, Gainesville, FL 32611-0690, USA.
Plant J. 2001 Apr;26(1):47-58. doi: 10.1046/j.1365-313x.2001.01006.x.
The plant hormone ethylene regulates many aspects of growth, development and responses to the environment. The Arabidopsis ETHYLENE INSENSITIVE3 (EIN3) protein is a nuclear-localized component of the ethylene signal-transduction pathway with DNA-binding activity. Loss-of-function mutations in this protein result in ethylene insensitivity in Arabidopsis. To gain a better understanding of the ethylene signal-transduction pathway in tomato, we have identified three homologs of the Arabidopsis EIN3 gene (LeEILs). Each of these genes complemented the ein3-1 mutation in transgenic Arabidopsis, indicating that all are involved in ethylene signal transduction. Transgenic tomato plants with reduced expression of a single LeEIL gene did not exhibit significant changes in ethylene response; reduced expression of multiple tomato LeEIL genes was necessary to reduce ethylene sensitivity significantly. Reduced LeEIL expression affected all ethylene responses examined, including leaf epinasty, flower abscission, flower senescence and fruit ripening. Our results indicate that the LeEILs are functionally redundant and positive regulators of multiple ethylene responses throughout plant development.
植物激素乙烯调控着植物生长、发育以及对环境响应的诸多方面。拟南芥乙烯不敏感3（EIN3）蛋白是乙烯信号转导途径中一个定位于细胞核且具有DNA结合活性的组分。该蛋白功能缺失突变会导致拟南芥对乙烯不敏感。为了更好地理解番茄中的乙烯信号转导途径，我们鉴定出了拟南芥EIN3基因的三个同源基因（LeEILs）。这些基因中的每一个都能在转基因拟南芥中互补ein3 - 1突变，这表明它们都参与乙烯信号转导。单个LeEIL基因表达降低的转基因番茄植株在乙烯响应方面未表现出显著变化；多个番茄LeEIL基因表达降低对于显著降低乙烯敏感性是必要的。LeEIL表达降低影响了所检测的所有乙烯响应，包括叶片偏上生长、花朵脱落、花朵衰老和果实成熟。我们的结果表明，LeEILs在植物整个发育过程中对多种乙烯响应在功能上是冗余的且起正向调节作用。
