Up-regulation of autophagy by low concentration of salicylic acid delays methyl jasmonate-induced leaf senescence

Abstract

Crosstalk between salicylic acid (SA) and jasmonic acid (JA) signaling plays an important role in molecular regulation of plant senescence. Our previous works 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.

Timing Is Everything In Autumn – Coordination Of Senescence Onset By A Transcriptional Program In Response To Environmental And Phytohormone Signals

“…A dual role of SA in regulating senescence and PCD has been established in several recent reports ( e . g ., Radojičic et al, 2018; Lee et al, 2020) and SA can delay senescence by activating autophagy (Yin et al, 2020, Rigault et al, 2021) or by alleviating ER stress by modulating glycosylation of proteins and metabolites (Huang et al, 2018; Lai et al, 2018; Lee et al, 2020). For example, BiP proteins (ER chaperones) can act as positive or negative cell death regulators depending on the activation of SA-mediated HR (Carvalho et al, 2014).…”

Interactions between autophagy and phytohormone signaling pathways in plants

“…These results suggest a model in which autophagy is induced due to increased SA production during senescence, generating a negative feedback loop that reduces the SA level to limit the senescence process [133]. The complexity of the interaction between senescence and autophagy is demonstrated by the observation that autophagy upregulation by a low concentration of SA can delay JA‐induced leaf senescence [136].…”

Co-expression module analysis reveals expression homogeneity of module members for coding and non-coding genes in sepsis

“…High-throughput technologies combined with a vast number of publicly available data and sophisticated algorithms enable the knowledge mining of disease-related genes [3][4][5][6][7][8]. Previous high-throughput studies usually focused on the function of individual genes associated with sepsis, ignoring the fact that genes tend to work together to carry out cellular processes and regulate signaling pathways [9][10][11]. From the perspective of systems biology, disease-related genes are frequently co-expressed across a set of samples, instead of functioning independently [12][13][14][15].…”

“…In this study, we investigated the genome-wide expression pro le of mRNAs and lncRNAs in six datasets, respectively. After that, these differentially expressed discoveries were used to construct gene co-expression networks and identify modules using WGCNA [11,25,26]. Then, we investigated the co-expression pattern of lncRNAs and mRNAs and compared the homogeneousity of the coexpression modules between sepsis and normal state.…”