The cell biology of primary cell walls during salt stress

Abstract

Salt stress simultaneously causes ionic toxicity, osmotic stress and oxidative stress, which directly impact plant growth and development. Plants have developed numerous strategies to adapt to saline environments. Whereas some of these strategies have been investigated and exploited for crop improvement, much remains to be understood, including how salt stress is perceived by plants and how plants coordinate effective responses to the stress. It is, however, clear that the plant cell wall is the first contact point between external salt and the plant. In this context, we have achieved significant advances in our understanding of halotropism, cell wall synthesis and integrity surveillance, as well as salt-related cytoskeletal rearrangements. Indeed, molecular mechanisms underpinning some of these processes have recently been elucidated. In this review, we aim to provide insights into how plants respond and adapt to salt stress, with a special focus on primary cell wall biology in the model plant Arabidopsis thaliana.

The regulation of plant cell wall organisation under salt stress

“…The direct interactions between microtubules, microtubule-linking proteins, and cellulose synthases made the proper microtubules and microfilaments organisation critical for the positioning and construction of cell wall components (Colin et al, 2023). At the same time, the genes in CesA family are specialised, with CesA1, CesA3, and CesA6 participating in primary cell wall synthesis, while CesA4, CesA7, and CesA8 are involved in secondary cell wall synthesis.…”

MdHB7‐like positively modulates apple salt tolerance by promoting autophagic activity and Na+ efflux

“…MdHB7-like inhibits excessive Na + accumulation through the MdHB7-like-MdCCX1 module Salt stress leads to excessive Na + accumulation, which induces severe damage in plants (Colin et al, 2023;Hussain et al, 2021;Munns & Tester, 2008). Na + transporters, such as the NHX family of proteins, positively regulate salt tolerance by promoting the transport of Na + into the vacuoles for compartmentation or export to the apoplastic space (Galvez et al, 2012;Li, Wu, et al, 2022;Solis et al, 2022;Wang, Guan, et al, 2019).…”

CiXTH29 and CiLEA4 Role in Water Stress Tolerance in Cichorium intybus Varieties

“…A detailed analysis of genes involved in cell wall metabolism has been reported in Arabidopsis seedlings, showing a generally reduced gene expression during soil water deficits, in particular, of genes promoting cell wall modification, such as expansins, pectin esterases and xyloglucan endotransglucosylase/hydrolases (XTHs) [ 21 , 22 ]. The involvement of expansins and XTHs in the remodeling of the wall has also been confirmed in the perspective of the new cell wall models that emphasize the binding between xyloglucans, the major hemicellulosic polysaccharides of dicot plants, and cellulose microfibrils at limited sites named ‘hot spots’ that can be modulated to control wall expansion [ 11 , 23 , 24 ]. The involvement of XTHs in the drought stress adaptation has been evidenced in durum wheat cultivars differing in their stress tolerances [ 25 ], in Arabidopsis and tomato seedlings overexpressing the Capsicum XTH3 gene [ 26 , 27 ] and in soybeans overexpressing GmXTH1 [ 28 ].…”

“…Plant cell wall integrity maintenance plays a key role in stress perception and stress responses in plants [ 7 , 8 , 9 ]. Although many questions remain to be addressed in this process, several cell wall sensors involved in cell wall integrity monitoring have been identified [ 10 , 11 ]. Drought stress affects the plant cell water potential and turgor pressure, causing cell wall modifications that involve the molecular organization and interaction of the wall polymers.…”