Arabidopsis seedling growth response and recovery to ethylene. A kinetic analysis
Arabidopsis seedling growth response and recovery to ethylene. A kinetic analysis
复制标题
DOI：
10.1104/pp.104.050369
复制
发表时间：
2004-10-01
期刊：
影响因子：
7.4
通讯作者：
Bleecker, AB
中科院分区：
文献类型：
--
作者：
Binder, BM;O'Malley, RC;Bleecker, AB
对植物激素乙烯的反应由拟南芥中的五个受体家族介导，这些受体在乙烯不存在的情况下作为反应途径的负调节剂起作用。在这项研究中，我们研究了快速动力学的生长抑制乙烯和乙烯撤退后，在下胚轴的黄化幼苗的野生型和乙烯受体缺陷的拟南芥品系的生长恢复。该分析揭示了在野生型中乙烯对生长的抑制有两个阶段：快速阶段，随后是延长的较慢阶段。在乙烯去除后约90分钟，生长完全恢复。所测试的受体无效突变对生长抑制的两个阶段都没有可测量的影响。然而，ETR 1，ETR 2和EIN 4中的功能丧失突变显着延长了乙烯去除后生长速率恢复的时间。具有etr 1 -6的植物; etr 2 -3; Ein 4 -4三重功能丧失突变体比任何单突变体需要更长的恢复时间，而ERS 1; ERS 2双突变体对恢复率没有影响，这表明受体结构域在恢复中起作用。用野生型基因组ETR 1转化ers 1 -2; etr 1 -7双突变体挽救了缓慢恢复表型，而His激酶失活的ETR 1构建体则没有。为了解释从生长抑制中快速恢复，提出了一个模型，其中簇状受体协同作用。
Responses to the plant hormone ethylene are mediated by a family of five receptors in Arabidopsis that act in the absence of ethylene as negative regulators of response pathways. In this study, we examined the rapid kinetics of growth inhibition by ethylene and growth recovery after ethylene withdrawal in hypocotyls of etiolated seedlings of wild-type and ethylene receptor-deficient Arabidopsis lines. This analysis revealed that there are two phases to growth inhibition by ethylene in wild type: a rapid phase followed by a prolonged, slower phase. Full recovery of growth occurs approximately 90 min after ethylene removal. None of the receptor null mutations tested had a measurable effect on the two phases of growth inhibition. However, loss-of-function mutations in ETR1, ETR2, and EIN4 significantly prolonged the time for recovery of growth rate after ethylene was removed. Plants with an etr1-6;etr2-3;ein4-4 triple loss-of-function mutation took longer to recover than any of the single mutants, while the ers1;ers2 double mutant had no effect on recovery rate, suggesting that receiver domains play a role in recovery. Transformation of the ers1-2;etr1-7 double mutant with wild-type genomic ETR1 rescued the slow recovery phenotype, while a His kinase-inactivated ETR1 construct did not. To account for the rapid recovery from growth inhibition, a model in which clustered receptors act cooperatively is proposed.