ABSTRACT Physiological adaptations, biochemical changes and growth performances of two sweet potatoes, Japanese Yellow (JPY) and Blackie (BLK), under NaCl salt stress were evaluated. Fallen leaves in JPY under 50 mM NaCl for 21 d were evidently observed, resulting in reduced leaf area (~60% reduction to that of control). Na+ content in the root of sweet potato BLK under salt stress was higher (54.18 mg g–1 DW) compared to the stem and leaf, whereas in case of JPY, all the plant organs were enriched by Na+, leading to reduced net photosynthetic rate (Pn) (71% reduction to that of control). Ca2+ and soluble sugar enrichments appeared to be the first line of defence mechanism in sweet potato to alleviate the Na+ toxicity, especially in BLK. A negative relation between Na+ accumulation and chlorophyll b content and a positive relation between chlorophyll b and Pn were demonstrated. Reduction in Pn in JPY under salt stress consequently reduced the leaf area, shoot height and fresh weight. It appeared that the Na+ enrichment, Ca2+ signalling and soluble sugars accumulation in the root tissues of cv. BLK played a key role in salt tolerance keeping Na+ in the vacuoles and maintaining growth of plants exposed to salt stress.

中文翻译：

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甘薯（Ipomoea batatas）基因型中钙和可溶性糖的富集及其对轻度 NaCl 盐胁迫的生理适应

摘要 评价了两种甘薯，日本黄薯 (JPY) 和黑薯 (BLK) 在 NaCl 盐胁迫下的生理适应性、生化变化和生长性能。在 JPY 中，在 50 mM NaCl 下 21 天明显观察到落叶，导致叶面积减少（比对照减少约 60%）。与茎和叶相比，盐胁迫下甘薯BLK根部的Na+含量更高（54.18 mg g-1 DW），而在JPY的情况下，所有植物器官都富含Na+，导致净光合速率降低(Pn)（比对照减少 71%）。Ca2+ 和可溶性糖富集似乎是甘薯中减轻 Na+ 毒性的第一道防线机制，尤其是在 BLK 中。Na+积累与叶绿素b含量呈负相关，叶绿素b与Pn呈正相关。盐胁迫下 JPY 中 Pn 的减少因此减少了叶面积、枝条高度和鲜重。看来，cv. 根组织中的 Na+ 富集、Ca2+ 信号传导和可溶性糖的积累。BLK 在使 Na+ 保持在液泡中并维持暴露于盐胁迫的植物生长的耐盐性方面发挥了关键作用。