Roles of the nuclear-encoded chloroplast SMR domain-containing PPR protein SVR7 in photosynthesis and oxidative stress tolerance in Arabidopsis
Roles of the nuclear-encoded chloroplast SMR domain-containing PPR protein SVR7 in photosynthesis and oxidative stress tolerance in Arabidopsis
复制标题
核编码叶绿体 SMR 结构域 PPR 蛋白 SVR7 在拟南芥光合作用和氧化应激耐受性中的作用
DOI：
10.1007/s12374-014-0041-1
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发表时间：
2014-10-01
影响因子：
2.9
通讯作者：
Yang, Zhong-Nan
中科院分区：
文献类型：
--
作者：
Lv, He-Xin;Huang, Chao;Yang, Zhong-Nan
先前报道，含有 PPR 蛋白 SVR7 的质体 SMR 结构域的突变会导致叶绿体 ATP 合成酶水平的特异性降低。在这里，我们分离出了SVR7的一个新的突变等位基因，命名为svr7-4，其中T-DNA被插入到SVR7的起始密码子中。 svr7-4的莲座叶，特别是在幼年阶段，由于叶绿素水平降低而显示出淡绿色表型。 P700和Fv/Fm值表明svr7-4中PSI和PSII的光合能力均受到损害。此外，我们通过组织化学染色和过氧化氢漂白实验分别发现svr7-4积累了更多的活性氧（ROS）并表现出较低的光氧化应激耐受性。当在光照下漂浮在水面上时，与野生型（WT）相比，svr7-4的叶子也具有增加的花青素积累。最后，我们发现 svr7-4 中 ZAT10、AtAPX1、CAT1 和 AtGPX2 四个非生物胁迫响应基因的表达水平上调。 SVR7 在植物发育过程中普遍表达。这些结果表明 SVR7 对于叶绿体中的正常光合作用和光氧化应激反应很重要。
The mutations of the plastid SMR domaincontaining PPR protein SVR7 were previously reported to cause a specific reduction in the chloroplast ATP synthase levels. Here, we isolated a new mutant allele of SVR7, named svr7-4, in which T-DNA is inserted into the initiation codon of SVR7. The rosette leaves of svr7-4, especially in the juvenile stage, showed a pale green phenotype as a result of a reduction in the chlorophyll levels. The values of P700 and Fv/Fm indicated that the photosynthetic capacities of both PSI and PSII were damaged in svr7-4. Furthermore, we found that the svr7-4 accumulated more reactive oxygen species (ROS) and showed lower photo-oxidative stress tolerance by histochemical staining and hydrogen peroxide bleaching experiments, respectively. The leaves of svr7-4 also had increased anthocyanins accumulation compared to that of wild-type (WT) when floated on water under light. Finally, we found that the expression levels of four abiotic stress-responsive genes including ZAT10, AtAPX1, CAT1 and AtGPX2 were up-regulated in svr7-4. SVR7 was expressed ubiquitously during plant development. These results indicate that SVR7 is important for normal photosynthesis and photo-oxidative stress responses in chloroplasts.