Disturbance of chlorophyll biosynthesis at Mg branch affects the chloroplast ROS homeostasis and Ca2+ signaling in Pisum sativum
Disturbance of chlorophyll biosynthesis at Mg branch affects the chloroplast ROS homeostasis and Ca2+ signaling in Pisum sativum
复制标题
Mg 分支叶绿素生物合成的干扰影响豌豆叶绿体 ROS 稳态和 Ca2 信号传导
DOI：
10.1007/s11240-016-1008-3
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发表时间：
2016-12-01
影响因子：
3
通讯作者：
Li, Xiaogang
中科院分区：
文献类型：
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作者：
Luo, Sha;Luo, Tao;Li, Xiaogang
据报道，活性氧（ROS）和钙（Ca2+）是两个关键的细胞内信号分子，据报道在叶绿素生物合成中起重要作用。在这项研究中，我们旨在研究叶绿素合成的紊乱是否影响叶绿体ROS和Ca2+稳态酶。叶绿素生物合成在MG分支上通过病毒诱导的基因沉默（VIGS）在豌豆（Pisum sativum）中编码MG螯合酶CHLI亚基的CHLI基因的基因沉默（VIGS）。随后，通过组织化学和荧光染色测定法评估了这些缺陷叶绿素豌豆植物中ROS和细胞内游离Ca2+浓度（[Ca2+]（i））。结果表明，超氧化物阴离子和过氧化氢主要是在豌豆维斯 - chli植物的黄色叶片中产生的。编码叶绿素抗氧化酶（抗氧化酶歧化酶，抗坏血酸酯过氧化物酶，谷胱甘肽还原酶，磷脂谷胱甘肽过氧化物酶，多氧蛋白和硫氧还蛋白）的基因的表达也降低了Vigs-Chli植物的叶片。此外，与VIGS-GFP对照植物的绿叶相比，VIGS-CHLI植物的黄色叶子的[Ca2+]（i）显着降低。编码Ca2+信号传导相关蛋白（类囊体Ca2+转运蛋白，钙调蛋白和钙调神经酶B样蛋白）的基因的表达在黄色的VIGS-CHLI叶片中下调。这些结果表明，通过沉默CHLI抑制叶绿素生物合成在Mg分支上会影响叶绿体ROS稳态和Ca2+信号传导，并下调了ROS清除基因和CA2+信号与信号相关的基因的表达。
Reactive oxygen species (ROS) and calcium (Ca2+), two crucial intracellular signaling molecules, have been reported to play important roles in chlorophyll biosynthesis. In this study, we aimed to investigate whether disturbance of chlorophyll synthesis affects chloroplast ROS and Ca2+ homeostases. Chlorophyll biosynthesis was inhibited at the Mg branch by virus-induced gene silencing (VIGS) of CHLI gene encoding the Mg chelatase CHLI subunit in pea (Pisum sativum). Subsequently, ROS and intracellular free Ca2+ concentration ([Ca2+](i)) in these chlorophyll-deficient pea plants were evaluated by histochemical and fluorescent staining assays. The results showed that the superoxide anion and hydrogen peroxide were predominantly generated in chloroplasts of the yellow leaves of pea VIGS-CHLI plants. The expression of genes encoding chloroplast antioxidant enzymes (CuZn-superoxide dismutase, ascorbate peroxidase, glutathione reductase, phospholipid glutathione peroxidase, peroxiredoxin and thioredoxins) were also decreased in the leaves of VIGS-CHLI plants compared with the control plants. Additionally, the [Ca2+](i) were significantly reduced in the yellow leaves of VIGS-CHLI plants compared with the green leaves of VIGS-GFP control plants. The expression of genes encoding Ca2+ signaling related proteins (thylakoid Ca2+ transporter, calmodulins and calcineurin B-like protein) was down-regulated in yellow VIGS-CHLI leaves. These results indicate that inhibition of chlorophyll biosynthesis at the Mg branch by silencing CHLI affects chloroplast ROS homeostasis and Ca2+ signaling and down-regulates the expression of ROS scavenging genes and Ca2+ signaling related genes.