LPS1编码琥珀酸脱氢酶铁硫亚基SDH2-1，影响水稻叶片衰老和产量

琥珀酸脱氢酶的铁硫亚基（SDH2）在植物线粒体的电子传递中起着关键作用。然而，SDH2基因是否参与叶片衰老和产量形成尚不清楚。在本研究中，我们从水稻（Oryza sativa）中分离到一个迟早衰突变体lps1。突变体叶片在分蘖后期出现褐斑，在灌浆后期和成熟期萎蔫。早衰叶片光合色素含量和净光合速率降低，叶绿体和线粒体降解。

图1. 野生型（WT）和lps1突变体之间的表型比较。

同时，lps1表现出穗小、结实率低、产量显著降低的特点。基因克隆和互补分析表明，导致突变表型的基因是OsSDH2-1（LOC iu Os08g02640），其中单核苷酸突变导致编码蛋白的氨基酸替换。OsSDH2-1基因在所有供试器官中均有表达，在叶片、根尖、子房和花药中均有较高表达。OsSDH2-1蛋白定位于线粒体。此外，lps1叶片和幼穗中活性氧（ROS）过量积累，导致叶片过早衰老，影响穗部发育和花粉功能。

图 2 OsSDH2-1线粒体定位

综上所述，OsSDH2-1在水稻叶片衰老和产量形成中起着重要作用。

The iron-sulfur subunit (SDH2) of succinate dehydrogenase plays a key role in electron transport in plant mitochondria. However, it is yet unknown whether SDH2 genes are involved in leaf senescence and yield formation. In this study, we isolated a late premature senescence mutant, lps1, in rice (Oryza sativa). The mutant leaves exhibited brown spots at late tillering stage and wilted at the late grain-filling stage and mature stage. In its premature senescence leaves, photosynthetic pigment contents and net photosynthetic rate were reduced; chloroplasts and mitochondria were degraded. Meanwhile, lps1 displayed small panicles, low seed-setting rate and dramatically reduced grain yield. Gene cloning and complementation analysis suggested that the causal gene for the mutant phenotype was OsSDH2-1 (LOC_Os08g02640), in which single nucleotide mutation resulted in an amino acid substitution in the encoded protein. OsSDH2-1 gene was expressed in all organs tested, with higher expression in leaves, root tips, ovary and anthers. OsSDH2-1 protein was targeted to mitochondria. Furthermore, reactive oxygen species (ROS), mainly H2O2, was excessively accumulated in leaves and young panicles of lps1, which could cause premature leaf senescence and affect panicle development and pollen function. Taken together, OsSDH2-1 plays a crucial role in leaf senescence and yield formation in rice.

来源：

https://www.mdpi.com/1422-0067/22/1/157

Li, C.; Liu, C.-Q.; Zhang, H.-S.; Chen, C.-P.; Yang, X.-R.; Chen, L.-F.; Liu, Q.-S.; Guo, J.; Sun, C.-H.; Wang, P.-R.; Deng, X.-J. LPS1, Encoding Iron-Sulfur Subunit SDH2-1 of Succinate Dehydrogenase, Affects Leaf Senescence and Grain Yield in Rice. Int. J. Mol. Sci. 2021, 22, 157.

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