Crosstalk between salicylic acid (SA) and jasmonic acid (JA) signaling plays an important role in regulation of plant senescence. Our previous work found that SA could delay methyl jasmonate (MeJA)-induced leaf senescence in a concentration-dependent manner. Here, the effect of low concentration of SA (LCSA) application on MeJA-induced leaf senescence was further assessed. High-throughput sequencing (RNA-Seq) results showed that LCSA did not have dominant effects on the genetic regulatory pathways of basal metabolism like nitrogen metabolism, photosynthesis and glycolysis. The ClusterONE was applied to identify discrete gene modules based on protein–protein interaction (PPI) network. Interestingly, an autophagy-related (ATG) module was identified in the differentially expressed genes (DEGs) that exclusively induced by MeJA together with LCSA. RT-qPCR confirmed that the expression of most of the determined ATG genes were upregulated by LCSA. Remarkably, in contrast to wild type (Col-0), LCSA cannot alleviate the leaf yellowing phenotype in autophagy defective mutants (atg5-1 and atg7-2) upon MeJA treatment. Confocal results showed that LCSA increased the number of autophagic bodies accumulated in the vacuole during MeJA-induced leaf senescence. Collectively, our work revealed up-regulation of autophagy by LCSA as a key regulator to alleviate MeJA-induced leaf senescence.

水杨酸（SA）和茉莉酸（JA）信号之间的串扰在调节植物衰老中起重要作用。我们以前的工作发现SA可以以浓度依赖的方式延迟茉莉酸甲酯（MeJA）诱导的叶片衰老。在这里，进一步评估了低浓度SA（LCSA）施用对MeJA诱导的叶片衰老的影响。高通量测序（RNA-Seq）结果表明，LCSA对诸如氮代谢，光合作用和糖酵解等基础代谢的遗传调控途径没有显性影响。ClusterONE被用于基于蛋白质-蛋白质相互作用（PPI）网络识别离散的基因模块。有趣的是，在仅由MeJA和LCSA共同诱导的差异表达基因（DEG）中鉴定了自噬相关（ATG）模块。RT-qPCR证实大多数测定的ATG基因的表达均被LCSA上调。值得注意的是，与野生型（Col-0）相比，LCSA不能缓解自噬缺陷型突变体中的叶片发黄表型（atJA5-1和atg7-2））。共聚焦结果表明，LCSA增加了MeJA诱导的叶片衰老过程中液泡中积累的自噬体的数量。总的来说，我们的工作揭示了LCSA作为减轻MeJA诱导的叶片衰老的关键调控因子的自噬上调。