Molecular Mechanisms Underlying Salt Stress Tolerance in Jojoba (Simmondsia Chinensis)

Abstract

The aim of this study was todetect the expression profiles of salt-related genes in the leaf transcriptome of Jojoba (Simmondsia chinensis) to decipher the molecular mechanisms underlying salt stress tolerance in this plant species. The analyzed RNA-Seq data identified numerous differentially expressed genesthat were mostly upregulated under salt (NaCl) stress conditions. The genes varied in their ability to limit cellular damage under stress conditions by regulatingthe production of reactive oxygen species (ROS). Some genes demonstrated the use of methylation/demethylation followed by intergenerational transmission of a “stress memory”. Other genes are known for their potential to produce proteins with superoxide dismutase (SOD) activity, the ability to detoxify metal ions and to produce molecular chaperones. Additional activities include regulating signal transductionandthe ion transport processes, the reprogramming of selective gene expression andthe maintenance of balanced sucrose content, ethylene signaling and homeostasis, the regulating of plasmodesmal permeability, ubiquitination,and selective protein degradation. Moreover, genes were also identified to be associated with cell wall remodeling, alleviating chlorophyll content, and accumulatinglower levels of sodium (Na+) and chloride (Cl-), as well as increased levels of lignin that function to support a plant’s integrity under salt stress. Overall, these data provide new insights into the molecular mechanisms at play during conditions of salt stress. These mechanisms ensure a plant’s survival and help to maintain its natural chemical compounds. These findings may be beneficial in furthering the use of this economically important plant.