Ntambiyukuri Aaron, Li Xia, Xiao Dong, Wang Aiqin, Zhan Jie, He Longfei
National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning 530004, China.
Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Nanning 530004, China.
Life (Basel). 2022 Aug 19;12(8):1271. doi: 10.3390/life12081271.
Peanut is among the most important oil crops in the world. In the southern part of China, peanut is highly produced; however, the arable land is acidic. In acidic soils, aluminum (Al) inhibits plant growth and development by changing the properties of the cell wall and causing the disorder of the intracellular metabolic process. Circadian rhythm is an internal mechanism that occurs about every 24 h and enables plants to maintain internal biological processes with a daily cycle. To investigate the effect of photoperiod and Al stress on the Al-induced programmed cell death (PCD), two peanut varieties were treated with 100 μM AlCl under three photoperiodic conditions (8/16, SD; 12/12, ND; 16/8 h, LD). The results show that Al toxicity was higher in ZH2 than in 99-1507 and higher under LD than under SD. Root length decreased by 30, 37.5, and 50% in ZH2 and decreased by 26.08, 34.78, and 47.82% in 99-1507 under SD, ND, and LD, respectively, under Al stress. Photoperiod and Al induced cell death and ROS production. MDA content, PME activity, and LOX activity increased under SD, ND, and LD, respectively, under Al stress both in ZH2 and 99-1507. APX, SOD, CAT, and POD activities were higher under SD, ND, and LD, respectively. Al stress increased the level of expression under SD and ND but decreased it under LD in both ZH2 and 99-1507. Contrastingly, expression levels increased exponentially and were higher under SD, LD, and ND, respectively, under Al stress. Our results will be a useful platform to research PCD induced by Al and gain new insights into the genetic manipulation of the circadian clock for plant stress response.
花生是世界上最重要的油料作物之一。在中国南方，花生产量很高；然而，耕地呈酸性。在酸性土壤中，铝（Al）通过改变细胞壁的性质和导致细胞内代谢过程紊乱来抑制植物生长发育。昼夜节律是一种大约每24小时发生一次的内部机制，使植物能够以每日周期维持内部生物过程。为了研究光周期和铝胁迫对铝诱导的程序性细胞死亡（PCD）的影响，在三种光周期条件下（8/16，短日照；12/12，中性日照；16/8小时，长日照），用100μM AlCl3处理两个花生品种。结果表明，ZH2中的铝毒性高于99-1507，长日照条件下的铝毒性高于短日照条件下。在铝胁迫下，ZH2的根长在短日照、中性日照和长日照条件下分别下降了30%、37.5%和50%，99-1507的根长分别下降了26.08%、34.78%和47.82%。光周期和铝诱导细胞死亡和活性氧产生。在铝胁迫下，ZH2和99-1507中，短日照、中性日照和长日照条件下的丙二醛含量、果胶甲酯酶活性和脂氧合酶活性分别增加。抗坏血酸过氧化物酶、超氧化物歧化酶、过氧化氢酶和过氧化物酶活性在短日照、中性日照和长日照条件下分别较高。铝胁迫在短日照和中性日照条件下增加了ZH2和99-1507中的表达水平，但在长日照条件下降低了表达水平。相反，在铝胁迫下，表达水平呈指数增加，在短日照、长日照和中性日照条件下分别较高。我们的结果将为研究铝诱导的PCD以及深入了解生物钟对植物胁迫反应的遗传操纵提供一个有用的平台。
