AtrbohD and AtrbohF positively regulate abscisic acid-inhibited primary root growth by affecting Ca2 signalling and auxin response of roots in Arabidopsis
AtrbohD and AtrbohF positively regulate abscisic acid-inhibited primary root growth by affecting Ca2 signalling and auxin response of roots in Arabidopsis
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DOI：
10.1093/jxb/ert228
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发表时间：
2013-11-01
影响因子：
6.9
通讯作者：
Hao, Fushun
中科院分区：
文献类型：
--
作者：
Jiao, Yiheng;Sun, Lirong;Hao, Fushun
来源于NADPH氧化酶AtrbohD和AtrbohF的ROS在脱落酸(ABA)抑制拟南芥初生根生长中起着重要作用。然而，这一过程背后的机制仍然难以捉摸。在本研究中，双突变体atrbohD/F1和atrbohD2/F2，其中AtrbohD和AtrbohF都被打乱，对ABA抑制根细胞伸长的敏感性低于野生型(WT)植物。此外，与WT相比，双突变体表现出根中ABA反应的减弱，包括ROS的产生，细胞内Ca-2的增加，以及质膜Ca-2通透通道的激活。外源H_2O_2可激活atrbohD_1/F_1根的钙电流。此外，外源外源生长素运输抑制剂萘基邻苯二甲酸能有效促进ABA对突变体根系生长的抑制作用。ABA诱导的根尖生长素敏感性的降低，WT比atrbohD_1/F_1更为明显。这些发现表明，AtrbohD和AtrbohF对于ABA促进的根中ROS的产生都是必需的。ROS激活了Ca-2信号通路，降低了根对生长素的敏感性，从而对ABA抑制的拟南芥初生根生长起到了积极的调节作用。
Reactive oxygen species (ROS) originating from the NADPH oxidases AtrbohD and AtrbohF play an important role in abscisic acid (ABA)-inhibited primary root growth in Arabidopsis. However, the mechanisms underlying this process remain elusive. In this study, the double mutant atrbohD1/F1 and atrbohD2/F2, in which both AtrbohD and AtrbohF were disrupted, were less sensitive to ABA suppression of root cell elongation than wild-type (WT) plants. Furthermore, the double mutants showed impaired ABA responses in roots, including ROS generation, cytosolic Ca-2 increases, and activation of plasma membrane Ca-2-permeable channels compared with WT. Exogenous H2O2 can activate the Ca-2 currents in roots of atrbohD1/F1. In addition, exogenous application of the auxin transport inhibitor naphthylphthalamic acid effectively promoted ABA inhibition of root growth of the mutants relative to that of WT. The ABA-induced decreases in auxin sensitivity of the root tips were more pronounced in WT than in atrbohD1/F1. These findings suggest that both AtrbohD and AtrbohF are essential for ABA-promoted ROS production in roots. ROS activate Ca-2 signalling and reduce auxin sensitivity of roots, thus positively regulating ABA-inhibited primary root growth in Arabidopsis.