The genetic orchestra of salicylic acid in plant resilience to climate change induced abiotic stress: critical review

Abstract

Climate change, driven by human activities and natural processes, has led to critical alterations in varying patterns during cropping seasons and is a vital threat to global food security. The climate change impose several abiotic stresses on crop production systems. These abiotic stresses include extreme temperatures, drought, and salinity, which expose agricultural fields to more vulnerable conditions and lead to substantial crop yield and quality losses. Plant hormones, especially salicylic acid (SA), has crucial roles for plant resiliency under unfavorable environments. This review explores the genetics and molecular mechanisms underlying SA's role in mitigating abiotic stress-induced damage in plants. It also explores the SA biosynthesis pathways, and highlights the regulation of their products under several abiotic stresses. Various roles and possible modes of action of SA in mitigating abiotic stresses are discussed, along with unraveling the genetic mechanisms and genes involved in responses under stress conditions. Additionally, this review investigates molecular pathways and mechanisms through which SA exerts its protective effects, such as redox signaling, cross-talks with other plant hormones, and mitogen-activated protein kinase pathways. Moreover, the review discusses potentials of using genetic engineering approaches, such as CRISPR technology, for deciphering the roles of SA in enhancing plant resilience to climate change related abiotic stresses. This comprehensive analysis bridges the gap between genetics of SA role in response to climate change related stressors. Overall goal is to highlight SA's significance in safeguarding plants and by offering insights of SA hormone for sustainable agriculture under challenging environmental conditions.

Keywords: CRISPR; Climate change; Genetic engineering; Mitigating abiotic stress; Salicylic acid.

Fig. 1

A Pathways of Salicylic Acid Biosynthesis in Plant, (B) Transcriptional Regulation network of Salicylic Acid Biosynthesis

Fig. 2

SA signaling and its cross-talk with ABA. A SA was found to increase the amount of ABA in response to stressors such as chilling, drought, and salinity which in turn has led to stomatal closure. B Shows Salicylic acid (SA) signaling in guard cells integrated with abscisic acid (ABA) signaling via the calcium-dependent protein kinase (CPK) pathway. SA triggers a ROS signal that activates CPKs, which then phosphorylate S59 and S120 of SLAC1, a protein that regulates stomatal closure. ABA also requires CPKs for the activation of SLAC1, but it also requires OST1, a protein kinase that is not involved in SA signaling. The two MAPKs, MPK9 and MPK12, also function downstream of ROS and Ca²⁺ in guard cell SA signaling and regulate SLAC1 activity indirectly. The molecular mechanism underlying the interdependence of the CPK-dependent and MPK-dependent pathways for SLAC1 activation is unknown

Fig. 3

Some potential mechanisms in plants for oxidative stress tolerance carried out by salicylic acid

Fig. 4

Cross-talks of SA with ABA, NO, and JA plant hormones under abiotic stress

Fig. 5

Effect of climate change-induced stress on plants (left) and effect of SA treatment on heat stress-exposed plants (right)

Fig. 6

SA induction of various mechanisms to induce tolerance to abiotic stress