Mechanism of ABA Signaling in Response to Abiotic Stress in Plants

194

105

The sessile nature of plants' life is endowed with a highly evolved defense system to adapt and survive under environmental extremes. To combat such stresses, plants have developed complex and well‐coordinated molecular and metabolic networks encompassing genes, metabolites, and acclimation responses. These modulate growth, photosynthesis, osmotic maintenance, and carbohydrate homeostasis. Under a given stress condition, sugars act as key players in stress perception, signaling, and are a regulatory hub for stress‐mediated gene expression ensuring responses of osmotic adjustment, scavenging of reactive oxygen species, and maintaining the cellular energy status through carbon partitioning. Several sugar transporters are known to regulate carbohydrate partitioning and key signal transduction steps involved in the perception of biotic and abiotic stresses. Sugar transporters such as SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTER (SWEETs), SUCROSE TRANSPORTERS (SUTs), and MONOSACCHARIDE TRANSPORTERS (MSTs) are involved in sugar loading and unloading as well as long‐distance transport (source to sink) besides orchestrating oxidative and osmotic stress tolerance. It is thus necessary to understand the structure–function relationship of these sugar transporters to fine‐tune the abiotic stress‐modulated responses. Advances in genomics have unraveled many sugars signaling components playing a key role in cross‐talk in abiotic stress pathways. An integrated omics approach may aid in the identification and characterization of sugar transporters that could become targets for developing stress tolerance plants to mitigate climate change effects and improve crop yield. In this review, we have presented an up‐to‐date analysis of the sugar homeostasis under abiotic stresses as well as describe the structure and functions of sugar transporters under abiotic stresses.

Section: The Interplay Between Sugars and Phytohormones Under Abioticmentioning

confidence: 99%

Plant sugars: Homeostasis and transport under abiotic stress in plants

Saddhe

Manuka

Suprasanna

2020

194

105

“…It has been seen that there occurs a cross‐talk between drought, cold and salinity responses. It has also been shown that ABF and DREB2A transcription pathways are also involved during drought tolerance (Saddhe et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Ion homeostasis for salinity tolerance in plants: a molecular approach

Amin

Rasool²,

Mir

et al. 2020

Soil salinity is one of the major environmental stresses faced by the plants. Sodium chloride is the most important salt responsible for inducing salt stress by disrupting the osmotic potential. Due to various innate mechanisms, plants adapt to the sodic niche around them. Genes and transcription factors regulating ion transport and exclusion such as salt overly sensitive (SOS), Na+/H+ exchangers (NHXs), high sodium affinity transporter (HKT) and plasma membrane protein (PMP) are activated during salinity stress and help in alleviating cells of ion toxicity. For salt tolerance in plants signal transduction and gene expression is regulated via transcription factors such as NAM (no apical meristem), ATAF (Arabidopsis transcription activation factor), CUC (cup‐shaped cotyledon), Apetala 2/ethylene responsive factor (AP2/ERF), W‐box binding factor (WRKY) and basic leucine zipper domain (bZIP). Cross‐talk between all these transcription factors and genes aid in developing the tolerance mechanisms adopted by plants against salt stress. These genes and transcription factors regulate the movement of ions out of the cells by opening various membrane ion channels. Mutants or knockouts of all these genes are known to be less salt‐tolerant compared to wild‐types. Using novel molecular techniques such as analysis of genome, transcriptome, ionome and metabolome of a plant, can help in expanding the understanding of salt tolerance mechanism in plants. In this review, we discuss the genes responsible for imparting salt tolerance under salinity stress through transport dynamics of ion balance and need to integrate high‐throughput molecular biology techniques to delineate the issue.

“…The ABA‐dependent pathway operates through PYR1/PYL/RCAR, PP2C, and SnRK 2 (Karle, Nair, & Kumar, 2020b). Under salt stress, ABA‐dependent signaling activates the SnRK2 members such as SnRK2.2, 2.3, and 2.6 (Karle, Nair, & Kumar, 2020b; Saddhe et al, 2017). The SnRK2 kinase phosphorylates and regulates the activity of downstream components including transcription factors, anion and cation channels, stomatal closure and changes in gene expression (Kumar et al, 2020; Figure 3).…”

Section: Crosstalk Between Salt Stress and Phytohormonesmentioning

confidence: 99%

Molecular insights into the role of plant transporters in salt stress response

Saddhe

Mishra

Kumar

2021

Self Cite

Salt stress disturbs the cellular osmotic and ionic balance, which then creates a negative impact on plant growth and development. The Na+ and Cl− ions can enter into plant cells through various membrane transporters, including specific and non‐specific Na+, K+, and Ca2+ transporters. Therefore, it is important to understand Na+ and K+ transport mechanisms in plants along with the isolation of genes, their characterization, the structural features, and their post‐translation regulation under salt stress. This review summarizes the molecular insights of plant ion transporters, including non‐selective cation transporters, cyclic nucleotide‐gated cation transporters, glutamate‐like receptors, membrane intrinsic proteins, cation proton antiporters, and sodium proton antiporter families. Further, we discussed the K+ transporter families such as high‐affinity K+ transporters, HAK/KUP/KT transporters, shaker type K+ transporters, and K+ efflux antiporters. Besides the ion transport process, we have shed light on available literature on epigenetic regulation of transport processes under salt stress. Recent advancements of salt stress sensing mechanisms and various salt sensors within signaling transduction pathways are discussed. Further, we have compiled salt‐stress signaling pathways, and their crosstalk with phytohormones.