Mg-chelatase I subunit 1 and Mg-protoporphyrin IX methyltransferase affect the stomatal aperture in Arabidopsis thaliana.
Mg-chelatase I subunit 1 and Mg-protoporphyrin IX methyltransferase affect the stomatal aperture in Arabidopsis thaliana.
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DOI：
10.1007/s10265-014-0636-0
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发表时间：
2014-07
影响因子：
2.8
通讯作者：
Kinoshita T
中科院分区：
文献类型：
--
作者：
Tomiyama M;Inoue S;Tsuzuki T;Soda M;Morimoto S;Okigaki Y;Ohishi T;Mochizuki N;Takahashi K;Kinoshita T
为了阐明气孔开放和关闭的分子机制，我们进行了遗传筛选，利用红外热成像分离气孔孔径突变体。我们确定了一个突变体命名为低温与开放气孔1（LOST 1），表现出降低叶温，更广泛的气孔开度，和一个浅绿色表型。基于地图的LOST 1基因座的分析表明，丢失1突变导致错义突变的镁螯合酶I亚基1（CHLI 1）基因，该基因编码的镁螯合酶复合物参与叶绿素合成的一个亚基。将野生型CHLI 1基因转化到LOST 1中补充了所有LOST 1表型。气孔损失1表现出部分ABA不敏感的表型类似的rtl 1，镁螯合酶H亚基错义突变体。Mg-原卟啉IX甲基转移酶（CHLM）基因编码叶绿素合成途径中的后续酶。我们研究了CHLM基因敲除突变体chlm的气孔运动，发现它也表现出ABA不敏感的表型。然而，LOST 1和CHLM幼苗都表现出ABA诱导的基因，如RAB 18和RD 29 B，响应阿坝的正常表达。这些结果表明，叶绿素合成酶，镁螯合酶复合物和CHLM，具体影响阿坝信号在气孔孔径的控制，并没有ABA诱导的基因表达的影响。本文的在线版本（doi：10.1007/s10265-014-0636-0）包含补充材料，可供授权用户使用。
To elucidate the molecular mechanisms of stomatal opening and closure, we performed a genetic screen using infrared thermography to isolate stomatal aperture mutants. We identified a mutant designated low temperature with open-stomata 1 (lost1), which exhibited reduced leaf temperature, wider stomatal aperture, and a pale green phenotype. Map-based analysis of the LOST1 locus revealed that the lost1 mutant resulted from a missense mutation in the Mg-chelatase I subunit 1 (CHLI1) gene, which encodes a subunit of the Mg-chelatase complex involved in chlorophyll synthesis. Transformation of the wild-type CHLI1 gene into lost1 complemented all lost1 phenotypes. Stomata in lost1 exhibited a partial ABA-insensitive phenotype similar to that of rtl1, a Mg-chelatase H subunit missense mutant. The Mg-protoporphyrin IX methyltransferase (CHLM) gene encodes a subsequent enzyme in the chlorophyll synthesis pathway. We examined stomatal movement in a CHLM knockdown mutant, chlm, and found that it also exhibited an ABA-insensitive phenotype. However, lost1 and chlm seedlings all showed normal expression of ABA-induced genes, such as RAB18 and RD29B, in response to ABA. These results suggest that the chlorophyll synthesis enzymes, Mg-chelatase complex and CHLM, specifically affect ABA signaling in the control of stomatal aperture and have no effect on ABA-induced gene expression. The online version of this article (doi:10.1007/s10265-014-0636-0) contains supplementary material, which is available to authorized users.