WHIRLY1 maintains leaf photosynthetic capacity in tomato by regulating the expression of RbcS1 under chilling stress
WHIRLY1 maintains leaf photosynthetic capacity in tomato by regulating the expression of RbcS1 under chilling stress
复制标题
WHIRLY1在低温胁迫下通过调节RbcS1的表达维持番茄叶片光合能力
DOI：
10.1093/jxb/eraa145
复制
发表时间：
2020
影响因子：
6.9
通讯作者：
Meng Qingwei
中科院分区：
文献类型：
--
作者：
Zhuang Kunyang;Wang Jieyu;Jiao Baozhen;Chen Chong;Zhang Junjie;Ma Nana;Meng Qingwei
Rubisco由8个大亚基(RBCL)和8个小亚基(RBCS)组成，是一种对冷胁迫敏感的主要光合酶。然而，植物如何在低温条件下保持较高的Rubisco含量在很大程度上尚不清楚。在此，我们报道了番茄WHIRLY1(SlWHY1)通过直接与SlRbcS1的启动子区域结合，正向调节了在低温胁迫下的Rubisco水平，从而激活了SlRbcS1的表达。与野生型相比，SLRbcS1过表达的品系具有更高的Rubisco含量和更强的抗冷性。实时荧光定量聚合酶链式反应分析表明，在5个RbcS基因中，只有SLRbcS1基因的表达受低温处理的上调。这些结果表明，SlWHIRLY1特异地提高了SLRbcS1的水平，并赋予其对低温胁迫的耐受性。SLRBCS1的氨基酸序列与另外两个RBC蛋白的氨基酸序列有92.67%的同源性，有3个残基是SLRBCS1所特有的。然而，SLRBCS1中这些残基突变为丙氨酸并不影响其在冷适应过程中的功能。因此，我们得出结论，高水平的Rubisco而不是SlRBCS1中的特定残基在番茄对冷害的耐受性中起着重要的作用。
Rubisco, which consists of eight large subunits (RBCLs) and eight small subunits (RBCSs), is a major photosynthetic enzyme that is sensitive to chilling stress. However, it is largely unclear how plants maintain high Rubisco content under low temperature conditions. Here, we report that tomato WHIRLY1 (SlWHY1) positively regulates the Rubisco level under chilling stress by directly binding to the promoter region ofSlRbcS1, resulting in the activation ofSlRbcS1expression.SlRbcS1-overexpressing lines had higher Rubisco contents and were more resistant to chilling stress compared with the wild type. Quantitative real-time PCR analyses showed that, among the fiveRbcS genes, onlySlRbcS1expression is up-regulated by chilling treatment. These results indicate that SlWHIRLY1 specifically enhances the levels ofSlRbcS1and confers tolerance to chilling stress. The amino acid sequence of SlRBCS1 shows 92.67% identity with those of another two RBCS proteins and three residues are specifically found in SlRBCS1. However, mutation of these residues to alanine in SlRBCS1 does not influence its function during cold adaptation. Thus, we conclude that high levels of Rubisco, but not the specific residues in SlRBCS1, play important roles in tolerance to chilling stress in tomato.