Interplay among glutathione, salicylic acid, and ethylene to combat environmental stress

Abstract

Plants withstand a variety of environmental stresses on a regular basis. In addition to its substantial function as a master antioxidant in living systems, the involvement of glutathione (GSH) in plant stress tolerance and management has long been known. However, how GSH interacts with other stress-related phytohormones such as salicylic acid (SA), jasmonic acid, ethylene (ET), and abscisic acid is still unknown. In this chapter we investigated the interaction of GSH with SA and ET to combat environmental stress conditions. In so doing, we developed transgenic tobacco lines, that is, NtGp lines, exhibiting enhanced GSH content. The significant abiotic stress tolerance potential (i.e., drought and salt) of these lines has been documented. Furthermore, transcriptomic and proteomic profiling of these transgenic lines identified the genes and proteins altered in enhanced GSH conditions and probably regulated by GSH as well. Several SA-related genes (i.e., PR1, GLS, MAPKK, NPR1, and others) and proteins (i.e., HSP 70, ADC, NBS-LRR, CA, PR10) were identified. Quantitative reverse-transcriptase polymerase chain reaction analysis further confirmed the expression level of SA-related genes in the NtGB line. Interestingly, in addition to SA, other major phytohormones such as ET have also been noted to be interactive with GSH. Together, a comprehensive analysis at the transcript and protein levels has demonstrated the interplay of GSH with SA and ET to combat environmental stress conditions in planta.