Both AtrbohD and AtrbohF are essential for mediating responses to oxygen deficiency in Arabidopsis
Both AtrbohD and AtrbohF are essential for mediating responses to oxygen deficiency in Arabidopsis
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DOI：
10.1007/s00299-017-2128-x
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发表时间：
2017-06-01
影响因子：
6.2
通讯作者：
Hao, Fu-Shun
中科院分区：
文献类型：
--
作者：
Liu, Bo;Sun, Lirong;Hao, Fu-Shun
关键信息AtrbohD和AtrbohF都能促进ADH、PDC、LDH和Ca~(2+)水平的升高，并诱导多种低氧应答基因的表达，从而提高拟南芥对缺氧的适应能力。然而，有关AtrbohD和AtrbohF在缺氧信号中共同作用的报道很少，潜在的机制仍然不清楚。在这里，我们证明了双零突变体atrbohD/F比野生型(WT)和单个突变体atrbohD和atrbohF对缺氧更敏感。在低氧条件下，WT的乙醇脱氢酶1(ADH1)和丙酮酸脱羧酶1(PDC1)的转录增强以及ADH、PDC和乳酸脱氢酶的活性在单一突变体中明显降低，而在双突变体中降低更明显。此外，atrbohD、atrbohF和atrbohF显著抑制了WT中ATP、H_2O_2和Ca~(2+)的产生，特别是在atrbohD/F中，低氧促进的一些低氧反应基因的表达也被抑制。这些基因包括乙烯反应因子73、乳酸脱氢酶、MYB转录因子2、蔗糖合成酶1、SUS4、热应激转录因子A2和热休克蛋白18.2。这些结果表明，AtrbohD和AtrbohF在介导低氧信号转导中都是必不可少的。AtrbohD和AtrbohF产生的H_2O_2触发钙离子升高，诱导多个低氧应答基因的表达，从而提高拟南芥对低氧胁迫的耐受性。这些发现为AtrbohF调节拟南芥对缺氧的反应的机制提供了新的见解。
Key message Both AtrbohD and AtrbohF promote the increases in activities of ADH, PDC, LDH, and Ca2+ levels, and induce the expression of multiple hypoxia response genes, thus improving Arabidopsis adaptation to oxygen deficiency.NADPH oxidase AtrbohD and AtrbohF cooperatively play key roles in regulation of growth and stress signaling in Arabidopsis. However, reports on AtrbohD and AtrbohF functioning together in hypoxia signaling are scarce, and the underlying mechanisms remain elusive. Here, we show that the double null mutant atrbohD/F is more sensitive to oxygen deprivation compared with wild type (WT) and the single mutant atrbohD and atrbohF. Under oxygen deficiency, enhancements of the transcripts of alcohol dehydrogenase 1 (ADH1) and pyruvate decarboxylase 1 (PDC1) and the activities of ADH, PDC and lactate dehydrogenase in WT are clearly reduced in the single mutants, and more strongly reduced in the double mutant. Moreover, increases in the production of ATP, H2O2 and Ca2+ in WT are significantly arrested in atrbohD, atrbohF, and especially in atrbohD/F. Hypoxia-promoted rise in the expression of some hypoxic responsive genes is also inhibited in atrbohD/F relative to WT, atrbohD and atrbohF. These genes include ethylene response factor 73, lactate dehydrogenase, MYB transcription factor 2, sucrose synthase 1 (SUS1), SUS4, heat stress transcription factor A2 and heat-shock protein 18.2. These results suggest that both AtrbohD and AtrbohF are essential for mediating hypoxia signaling. H2O2 derived from AtrbohD and AtrbohF triggers the Ca2+ increase and induces the expression of multiple hypoxia response genes, thus improving Arabidopsis tolerance to low-oxygen stress. These findings provide new insights into the mechanisms of AtrbohF in regulating the responses to oxygen deprivation in Arabidopsis.