The battle of two ions: Ca²⁺ signalling against Na⁺ stress

Abstract

Soil salinity adversely affects plant growth, crop yield and the composition of ecosystems. Salinity stress impacts plants by combined effects of Na toxicity and osmotic perturbation. Plants have evolved elaborate mechanisms to counteract the detrimental consequences of salinity. Here we reflect on recent advances in our understanding of plant salt tolerance mechanisms. We discuss the embedding of the salt tolerance-mediating SOS pathway in plant hormonal and developmental adaptation. Moreover, we review newly accumulating evidence indicating a crucial role of a transpiration-dependent salinity tolerance pathway, that is centred around the function of the NADPH oxidase RBOHF and its role in endodermal and Casparian strip differentiation. Together, these data suggest a unifying and coordinating role for Ca signalling in combating salinity stress at the cellular and organismal level.

Salt Stress Reduced the Seedling Growth of Two Larch Species Under Elevated Ozone

“…In particular, we observed significant species differences regarding the relationship between needle Na and Ca contents, suggesting that the Na sensitivity to needle Ca contents was higher in JL than DL. Ca plays an important role in the cell membrane, cell wall stabilization, signaling functions, and the mitigation of salinity (Köster et al, 2019). These results supported our hypothesis that salt tolerance would be greater in DL, and that mineral homeostasis was related to other mineral elements apart from K. DL may obtain the adaptive capacity to salt stress as the original distribution of the species where the primary salinization is likely to occur cause to drought condition (Polezhaeva et al, 2010;Mamet et al, 2019).…”

Overexpression of a Novel ROP Gene from the Banana (MaROP5g) Confers Increased Salt Stress Tolerance

“…For example, under salt stress, the SOS1 and SOS2 proteins regulate Na + /K + homeostasis in A. thaliana ; once the calcium binding protein SOS3 senses an increase in cytosolic calcium concentration, the SOS3–SOS2 protein kinase complex activates the SOS1 ion transporter [ 42 , 43 ]. In addition, calcium (Ca 2+ ), as a second messenger, plays an important role in salt stress processes [ 39 , 44 ]. Ca 2+ increase can be decoded and recognized by Ca 2+ sensors, including CBLs, CIPKs, and CDPKs [ 44 ].…”

“…In addition, calcium (Ca 2+ ), as a second messenger, plays an important role in salt stress processes [ 39 , 44 ]. Ca 2+ increase can be decoded and recognized by Ca 2+ sensors, including CBLs, CIPKs, and CDPKs [ 44 ]. CBLs recognize the increase in cytosolic Ca 2+ concentration triggered by Na + accumulation [ 39 ].…”

Both NaCl and H2O2 Long-Term Stresses Affect Basal Cytosolic Ca2+ Levels but Only NaCl Alters Cytosolic Ca2+ Signatures in Arabidopsis

“…Additionally, the molecular mechanisms of ROS sensing in plant cells are still unknown, and probably ROS activation of Ca 2+ permeable channels may serve as an ROS perception process ( Pei et al, 2000 ; Waring, 2005 ; Miller et al, 2010 ). Note that the rapid rise in NaCl-induced [Ca 2+ ] i as well as the NaCl-triggered overproduction of ROS possibly function as critical integrators, mediating stress signal perception, signal transduction, and adaptation ( Xie et al, 2011 ; Ma et al, 2012 ; Jiang et al, 2013 ; Ben et al, 2015 ; Köster et al, 2018 ). The salt stress-induced [Ca 2+ ] i increases precede the production of H 2 O 2 signaling molecule ( Yang and Poovaiah, 2002 ).…”