A homolog of ETHYLENE OVERPRODUCER, OsETOL1, differentially modulates drought and submergence tolerance in rice
A homolog of ETHYLENE OVERPRODUCER, OsETOL1, differentially modulates drought and submergence tolerance in rice
复制标题
乙烯过量生产者 OsETOL1 的同源物可差异调节水稻的干旱和淹水耐受性
DOI：
10.1111/tpj.12508
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发表时间：
2014-06-01
期刊：
影响因子：
7.2
通讯作者：
Xiong, Lizhong
中科院分区：
文献类型：
--
作者：
Du, Hao;Wu, Nai;Xiong, Lizhong
淹水和干旱是作物生产的主要限制因素。然而，关于植物对两种极端水分的不同或重叠机制的研究报告非常有限。在这里，我们报告了一个乙烯过量生产者1-like基因（OsETOL 1），差异调节水稻（Oryza sativa L.）的耐旱性和耐淹性。OsETOL 1的两个等位突变体在穗发育期表现出对干旱胁迫的抗性增强。有趣的是，突变体在幼苗和穗发育期的淹水胁迫下表现出显着较慢的生长速率。OsETOL 1在水稻中的过量表达（OE）导致了与突变体相反的表型。OsETOL 1转录本对非生物胁迫的响应是不同的。OsETOL 1与1-氨基-环丙烷-1-羧酸（ACC）合酶（ACS）的同源物OsACS 2相互作用，后者是乙烯生物合成的限速酶。在Osacs 2突变体和OsETOL 1-OE植株中，ACC和乙烯含量显著降低，而外源ACC使OsETOL 1和OsETOL 1-OE在淹水胁迫下的表型恢复到野生型，表明OsETOL 1在乙烯生物合成中起负作用。OsETOL 1和OsETOL 1-OE植株中与碳水化合物催化和发酵相关的多个基因的表达发生了显著变化，表明OsETOL 1可能影响能量代谢。这些结果表明OsETOL 1通过调节乙烯的产生和能量代谢在干旱和淹水胁迫下的耐受性中发挥着独特的作用。对水稻中3个乙烯过量生产者（ETOL）家族成员的表达和功能比较的结果进一步支持OsETOL 1在两种水分胁迫响应中的特异性作用。
Submergence and drought are major limiting factors for crop production. However, very limited studies have been reported on the distinct or overlapping mechanisms of plants in response to the two water extremes. Here we report an ETHYLENE OVERPRODUCER 1-like gene (OsETOL1) that modulates differentially drought and submergence tolerance in rice (Oryza sativa L.). Two allelic mutants of OsETOL1 showed increased resistance to drought stress at the panicle development stage. Interestingly, the mutants exhibited a significantly slower growth rate under submergence stress at both the seedling and panicle development stages. Over-expression (OE) of OsETOL1 in rice resulted in reverse phenotypes when compared with the mutants. The OsETOL1 transcript was differentially responsive to abiotic stresses. OsETOL1 was found to interact with OsACS2, a homolog of 1-amino-cyclopropane-1-carboxylate (ACC) synthase (ACS), which acts as a rate-limiting enzyme for ethylene biosynthesis. In the osacs2 mutant and OsETOL1-OE plants, ACC and ethylene content were decreased significantly, and exogenous ACC restored the phenotype of osetol1 and OsETOL1-OE to wild-type under submergence stress, implying a negative role for OsETOL1 in ethylene biosynthesis. The expression of several genes related to carbohydrate catabolism and fermentation showed significant changes in the osetol1 and OsETOL1-OE plants, implying that OsETOL1 may affect energy metabolism. These results together suggest that OsETOL1 plays distinct roles in drought and submergence tolerance by modulating ethylene production and energy metabolism. Findings from the expression and functional comparison of three ethylene overproducer (ETOL) family members in rice further supported the specific role of OsETOL1 in the responses to the two water stresses.