Abscisic Acid Signaling and Abiotic Stress Tolerance in Plants: A Review on Current Knowledge and Future Prospects

Abstract

Abiotic stress is one of the severe stresses of environment that lowers the growth and yield of any crop even on irrigated land throughout the world. A major phytohormone abscisic acid (ABA) plays an essential part in acting toward varied range of stresses like heavy metal stress, drought, thermal or heat stress, high level of salinity, low temperature, and radiation stress. Its role is also elaborated in various developmental processes including seed germination, seed dormancy, and closure of stomata. ABA acts by modifying the expression level of gene and subsequent analysis of cis-and trans-acting regulatory elements of responsive promoters. It also interacts with the signaling molecules of processes involved in stress response and development of seeds. On the whole, the stress to a plant can be susceptible or tolerant by taking into account the coordinated activities of various stress-responsive genes. Numbers of transcription factor are involved in regulating the expression of ABA responsive genes by acting together with their respective cis-acting elements. Hence, for improvement in stresstolerance capacity of plants, it is necessary to understand the mechanism behind it. On this ground, this article enlightens the importance and role of ABA signaling with regard to various stresses as well as regulation of ABA biosynthetic pathway along with the transcription factors for stress tolerance.

Ethylene Receptors Signal via a Noncanonical Pathway to Regulate Abscisic Acid Responses

“…Abiotic stress conditions are known to cause an increase in ABA biosynthesis leading to inhibition of germination (Vishwakarma et al, 2017). We therefore treated germinating seeds with 100 mM norflurazon (NF) to inhibit the biosynthesis of ABA in the germinating seeds.…”

Regulation of the biosynthesis of endogenous nitric oxide and abscisic acid in stored peaches by exogenous nitric oxide and abscisic acid

“…Abscisic acid (ABA) is a sesquiterpenoid and a signal molecule that is important in plant tolerance to stress factors . ABA can be synthesized by a direct pathway in fungi and by an indirect pathway in plants .…”

“…ABA can be synthesized by a direct pathway in fungi and by an indirect pathway in plants . In the indirect pathway, ABA is produced by oxidative cleavage of a C 40 carotenoid precursor . Some endogenous enzymes, including aldehyde oxidase (AO), 9‐ cis ‐epoxycarotenoid dioxygenase (NCED), and zeaxanthin epoxidase (ZEP), may be involved in the indirect pathway of ABA synthesis …”

Differential gene expression in fronds and stolons of the siphonous macroalga, Caulerpa lentillifera

“…However, relationships among preferentially expressed plant hormone‐associated genes within the two structures seem complicated, especially for abscisic acid (ABA) signaling. The ABA signaling pathway is associated with environmental stress responses (Vishwakarma et al, ). Preferential expression of genes for two components of ABA signaling, PP2C and SnRK2 , were observed in both of fronds and stolons.…”