Salicylic acid alleviates the salt toxicity in kenaf by activating antioxidant system and regulating crucial pathways and genes

Abstract

High salinity is one of the major abiotic stresses that limit crop production. Salicylic acid (SA) has been shown to ameliorate the adverse effects of environmental stress on plants. However, the molecular basis of salicylic acid-mediated salinity tolerance in kenaf is still unclear. To uncover the toxic alleviation effects of SA on kenaf salt stress, the morphological, physiological indexes, and transcriptomic regulating were assayed under NaCl stress with (or without) SA pretreated. The result showed that application of exogenous SA significantly alleviated the repressive effects of kenaf under salt stress, including agronomic traits, antioxidant enzyme systems, and several important pathways and involved differentially expressed genes (DEGs). In addition, some transcription factors (TFs) such as NAC, MYB, bHLH, ERF and enzyme activity-related genes such POD were also significantly changed with exogenous SA application. Virus‑Induced Gene Silencing (VIGS) of a differentially expressed TFs, HcNAC29, reduced salt tolerance in kenaf. Integrating physiological and transcriptomic analyses, a number of important pathways were found to be important for SA-mediated salinity tolerance in kenaf, including phenylpropanoid biosynthesis, flavonoid biosynthesis, plant hormone signaling pathway, and some transcription factors such as NAC. The data presented here may be useful in further elucidating the multiple regulatory roles of SA in plant responses to abiotic stresses.