DEXH Box RNA Helicase-Mediated Mitochondrial Reactive Oxygen Species Production in Arabidopsis Mediates Crosstalk between Abscisic Acid and Auxin Signaling
DEXH Box RNA Helicase-Mediated Mitochondrial Reactive Oxygen Species Production in Arabidopsis Mediates Crosstalk between Abscisic Acid and Auxin Signaling
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DOI：
10.1105/tpc.112.098707
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发表时间：
2012-05-01
期刊：
影响因子：
11.6
通讯作者：
Gong, Zhizhong
中科院分区：
文献类型：
--
作者：
He, Junna;Duan, Ying;Gong, Zhizhong
众所周知，脱落酸（阿坝）信号转导过程中通过质膜相关的NADPH氧化酶促进活性氧（ROS）的产生。然而，来自细胞器的ROS是否可以作为阿坝信号转导的第二信使在很大程度上是未知的。在这里，我们确定了阿坝过度敏感的突变体，abo 6，在ABA介导的抑制主根生长的遗传筛选。ABO 6编码一种DEXH盒RNA解旋酶，参与调节线粒体中复合体I的几个基因的剪接。abo 6突变体在线粒体中积累了更多的活性氧，这是使用线粒体超氧化物指示剂循环排列的黄色荧光蛋白建立的。阿坝不敏感基因abi 1 -1和abi 2 -1的两个显性负突变显著降低了线粒体中ROS的产生。abo 6的阿坝敏感性也可以被atrbohF突变所损害。ABA介导的抑制种子萌发和初生根生长在abo 6中被释放的还原型谷胱甘肽和外源生长素的培养基中。abo 6突变极大地降低了生长素应答标记物ProDR 5：GUS（用于合成的生长素应答元件D1-4，其在5 '端具有定点突变体，来自大豆）：β-葡萄糖醛酸苷酶）和吲哚-3-乙酸诱导2：GUS的表达。因此，我们的研究结果提供了阿坝和生长素之间的相互作用，通过从线粒体产生活性氧的分子证据。这种相互作用调节拟南芥的主根生长和种子萌发。
It is well known that abscisic acid (ABA) promotes reactive oxygen species (ROS) production through plasma membrane-associated NADPH oxidases during ABA signaling. However, whether ROS from organelles can act as second messengers in ABA signaling is largely unknown. Here, we identified an ABA overly sensitive mutant, abo6, in a genetic screen for ABA-mediated inhibition of primary root growth. ABO6 encodes a DEXH box RNA helicase that is involved in regulating the splicing of several genes of complex I in mitochondria. The abo6 mutant accumulated more ROS in mitochondria, as established using a mitochondrial superoxide indicator, circularly permuted yellow fluorescent protein. Two dominant-negative mutations in ABA insensitive1 (abi1-1) and abi2-1 greatly reduced ROS production in mitochondria. The ABA sensitivity of abo6 can also be compromised by the atrbohF mutation. ABA-mediated inhibition of seed germination and primary root growth in abo6 was released by the addition of reduced GSH and exogenous auxin to the medium. Expression of auxin-responsive markers ProDR5:GUS (for synthetic auxin response element D1-4 with site-directed mutants in the 5'-end from soybean): beta-glucuronidase) and Indole-3-acetic acid inducible2:GUS was greatly reduced by the abo6 mutation. Hence, our results provide molecular evidence for the interplay between ABA and auxin through the production of ROS from mitochondria. This interplay regulates primary root growth and seed germination in Arabidopsis thaliana.