Zheng Junming, Ge Jinjin, Li Pengyu, Xin Boning, Lin Feng, Zhang Wenhua, Jing Wen
National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Biochem Biophys Res Commun. 2025 Feb 16;749:151355. doi: 10.1016/j.bbrc.2025.151355. Epub 2025 Jan 17.
Leaf senescence is a complex developmental process that is regulated by multiple genetic and environmental factors. Understanding the mechanisms underlying the regulation of leaf senescence will provide valuable insights for manipulation of this trait in crops. Here, we report that the ATP-binding cassette (ABC) transporter OsPDR1 is involved in promoting leaf senescence in rice. Mutation and overexpression of OsPDR1 delayed and accelerated natural leaf senescence at the seedling and mature stages, respectively. The level of OsPDR1 transcript in leaves was significantly upregulated by dark treatment. Overexpression of OsPDR1 accelerated dark-induced leaf senescence by enhancing senescence-associated gene expression, whereas its mutation delayed dark-induced leaf senescence. OsPDR1 is coexpressed with the rice N-acetylserotonin methyltransferase gene, OsASMT1, encoding a key enzyme in melatonin biosynthesis. OsASMT1 expression levels and melatonin content were significantly decreased in OsPDR1-overexpressing lines but significantly increased in ospdr1 mutants compared to the wild type. Exogenous melatonin application markedly decreased the accumulation of reactive oxygen species (ROS) and delayed leaf senescence in PDR1.3-overexpressing plants. These results indicated that OsPDR1 plays an important role in the regulation of leaf senescence by influencing melatonin biosynthesis in rice.
叶片衰老 是一个复杂的发育过程，受多种遗传和环境因素调控。了解叶片衰老调控的潜在机制将为作物中该性状的调控提供有价值的见解。在此，我们报道ATP结合盒（ABC）转运蛋白OsPDR1参与促进水稻叶片衰老。OsPDR1的突变和过表达分别在幼苗期和成熟期延迟和加速了自然叶片衰老。黑暗处理显著上调了叶片中OsPDR1转录本的水平。OsPDR1的过表达通过增强衰老相关基因的表达加速了黑暗诱导的叶片衰老，而其突变则延迟了黑暗诱导的叶片衰老。OsPDR1与水稻N - 乙酰血清素甲基转移酶基因OsASMT1共表达，OsASMT1编码褪黑素生物合成中的关键酶。与野生型相比，OsPDR1过表达株系中OsASMT1的表达水平和褪黑素含量显著降低，而在ospdr1突变体中则显著增加。外源施加褪黑素显著降低了过表达PDR1.3植株中活性氧（ROS）的积累并延迟了叶片衰老。这些结果表明，OsPDR1通过影响水稻中的褪黑素生物合成在叶片衰老调控中发挥重要作用。
