Payton S, Fray R G, Brown S, Grierson D
BBSRC Research Group in Plant Gene Regulation, Department of Physiology and Environmental Science, University of Nottingham, Loughborough, UK.
Plant Mol Biol. 1996 Sep;31(6):1227-31. doi: 10.1007/BF00040839.
Using the Arabidopsis ethylene receptor ETR1 as a probe, we have isolated a tomato homologue (tETR) from a ripening cDNA library. The predicted amino acid sequence is 70% identical to ETR1 and homologous to a variety of bacterial two component response regulators over the histidine kinase domain. Sequencing of four separate cDNAs indicates that tETR lacks the carboxyl terminal response domain and is identical to that encoded by the tomato Never ripe gene. Ribonuclease protection showed tETR mRNA was undetectable in unripe fruit or pre-senescent flowers, increased in abundance during the early stages of ripening, flower senescence, and in abscission zones, and was greatly reduced in fruit of ripening mutants deficient in ethylene synthesis or response. These results suggest that changes in ethylene sensitivity are mediated by modulation of receptor levels during development.
以拟南芥乙烯受体ETR1作为探针，我们从一个成熟cDNA文库中分离出了一个番茄同源物（tETR）。预测的氨基酸序列与ETR1有70%的同一性，并且在组氨酸激酶结构域上与多种细菌双组分响应调节因子同源。对四个独立cDNA的测序表明，tETR缺乏羧基末端响应结构域，并且与番茄永不成熟基因所编码的序列相同。核糖核酸酶保护实验表明，在未成熟果实或衰老前的花中检测不到tETR mRNA，在成熟早期、花衰老过程以及脱落区中其丰度增加，而在乙烯合成或响应缺陷的成熟突变体果实中则大幅减少。这些结果表明，乙烯敏感性的变化是由发育过程中受体水平的调节介导的。
