Salinity stress effects on cell wall components and pectin localization in spinach (Spinacia oleracea L.)
Jia Liu, Shuoshuo Liang, Yafei Shi, Haruyuki Fujimaki, Ryoichi Araki, A. Egrinya Eneji, Irshad Muhammad, Xiaojing Liu, Ping An
Abstract
Salt stress is a key environmental limitation to plant growth and productivity, mainly because of detrimental osmotic and ionic effects. We examined salt stress effects on spinach ( Spinacia oleracea ) root growth, cell wall extensibility and chemical composition and localization of pectin at varying NaCl concentration gradients (0, 100, 200 and 300 mM NaCl). Root elongation and cell wall extensibility exhibited concentration-dependent inhibition, inversely correlated with pectin, hemicellulose I, and cellulose accumulation. Histological data indicated root epidermal deformation and hyperplastic root hair development under salinity. Crucially, compartment-specific pectin deposition in the endodermis was identified as a key response to salt stress, potentially modulating apoplastic water and solute flux. This study established that salinity induces cell wall compositional remodeling and morphological reorganization in spinach roots, with structural rigidity prioritized over growth under extreme salinity stress.