Zhang Jiaojiao, Xu Jianfei, Bian Chunsong, Duan Shaoguang, Hu Jun, Qin Junhong, Wu Huan, He Ming, Jian Yinqiao, Duan Yanfeng, Liu Jiangang, Wang Wanxing, Li Guangcun, Jin Liping
State Key Laboratory of Vegetable Biobreeding, Key Laboratory of Biology and Genetic Improvement of Tuber and Root Crop of Ministry of Agriculture and Rural Affairs, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Int J Mol Sci. 2025 May 5;26(9):4389. doi: 10.3390/ijms26094389.
Senescence impacts plant growth and yields in tetraploid potatoes ( L.). Because of their homogenous tetraploid features, it is a major challenge to understand the genetic basis and molecular mechanisms of senescence. Here, we identified a novel central senescence regulator (Nicotinate-nucleotide pyrophosphorylase QPT/) through map-based cloning. Overexpression of accelerated senescence in the late-senescence variety, with NAD content declining by around 40%. CRISPR/Cas9-induced mutant exhibited extremely early senescence, and the NAD content was reduced by 87% along with reduced chlorophyll content and photosynthesis. Moreover, the downstream products of the NAD synthesis pathway, such as NaMN, NAD, or niacin, can refresh the mutant to grow normally. Further, the transcriptomics and metabolomics data unveiled that the disrupting of impairs NAD metabolism, accelerating plant senescence through multiple biological levels. Our results show that is indispensable for NAD synthesis, and targeting the -mediated NAD synthesis pathway could be a useful strategy to regulate senescence in potato breeding preprograms.
衰老影响四倍体马铃薯（茄属）的生长和产量。由于其同源四倍体特征，了解衰老的遗传基础和分子机制是一项重大挑战。在此，我们通过图位克隆鉴定出一种新型的中心衰老调节因子（烟酸核苷酸焦磷酸化酶QPT/）。在晚衰品种中过表达QPT会加速衰老，NAD含量下降约40%。CRISPR/Cas9诱导的QPT突变体表现出极早期衰老，NAD含量降低87%，同时叶绿素含量和光合作用降低。此外，NAD合成途径的下游产物，如NaMN、NAD或烟酸，可以使QPT突变体恢复正常生长。进一步的转录组学和代谢组学数据表明，QPT的破坏会损害NAD代谢，通过多个生物学水平加速植物衰老。我们的结果表明，QPT对NAD合成不可或缺，针对QPT介导的NAD合成途径可能是马铃薯育种前期计划中调节衰老的有用策略。
