Stomatal movements are enabled by changes in guard cell turgor facilitated via transient accumulation of inorganic and organic ions imported from the apoplast or biosynthesized within guard cells. Under salinity, excess salt ions accumulate within plant tissues resulting in osmotic and ionic stress. To elucidate whether (a) Na⁺ and Cl⁻ concentrations increase in guard cells in response to long‐term NaCl exposure and how (b) guard cell metabolism acclimates to the anticipated stress, we profiled the ions and primary metabolites of leaves, the apoplast and isolated guard cells at darkness and during light, that is, closed and fully opened stomata. In contrast to leaves, the primary metabolism of guard cell preparations remained predominantly unaffected by increased salt ion concentrations. Orchestrated reductions of stomatal aperture and guard cell osmolyte synthesis were found, but unlike in leaves, no increases of stress responsive metabolites or compatible solutes occurred. Diverging regulation of guard cell metabolism might be a prerequisite to facilitate the constant adjustment of turgor that affects aperture. Moreover, the photoperiod‐dependent sucrose accumulation in the apoplast and guard cells changed to a permanently replete condition under NaCl, indicating that stress‐related photosynthate accumulation in leaves contributes to the permanent closing response of stomata under stress.

中文翻译：

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保卫细胞代谢适应长期盐度

气孔运动是由保卫细胞膨胀的变化引起的，该变化通过从质外体导入的或在保卫细胞内生物合成的无机和有机离子的瞬时积累而促进。在盐度下，过量的盐离子会积聚在植物组织内，从而导致渗透压和离子胁迫。为了阐明是否（一）的Na ⁺和Cl ^-长期暴露于NaCl的情况下，保卫细胞的浓度增加，以及（b）保卫细胞的代谢如何适应预期的压力，我们在黑暗中和光照期间分析了叶片，质外体和离体保卫细胞的离子和主要代谢产物，是封闭的和完全打开的气孔。与叶子相反，保卫细胞制剂的主要代谢主要不受盐离子浓度增加的影响。发现气孔孔径的有序减少和保卫细胞渗透液的合成，但与叶片不同，胁迫响应代谢产物或相容性溶质没有增加。保卫细胞代谢的不同调节可能是促进影响口径的不断膨胀的先决条件。而且，