Department of Resources and Environmental Science, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
PLoS One. 2021 Aug 10;16(8):e0256000. doi: 10.1371/journal.pone.0256000. eCollection 2021.
The sensitivity of cotton to salt stress depends on the genotypes and salt types. Understanding the mechanism of ion homeostasis under different salt stresses is necessary to improve cotton performance under saline conditions. A pot experiment using three salt stresses saline stress (NaCl+Na2SO4), alkaline stress (Na2CO3+NaHCO3), and saline-alkaline stress (NaCl+Na2SO4+Na2CO3+NaHCO3) and two cotton varieties (salt-tolerant variety L24 and salt-sensitive variety G1) was conducted. The growth, ion concentrations, and Na+ transport-related gene expression in the cotton varieties were determined. The inhibitory effects of saline-alkaline stress on cotton growth were greater than that of either saline stress or alkaline stress alone. The root/shoot ratio under alkaline stress was significantly lower than that under saline stress. The salt-tolerant cotton variety had lower Na and higher K concentrations in the leaves, stems and roots than the salt-sensitive variety under different salt stresses. For the salt-sensitive cotton variety, saline stress significantly inhibited the absorption of P and the transport of P, K, and Mg, while alkaline stress and saline-alkaline stress significantly inhibited the uptake and transport of P, K, Ca, Mg, and Zn. Most of the elements in the salt-tolerant variety accumulated in the leaves and stems under different salt stresses. This indicated that the salt-tolerant variety had a stronger ion transport capacity than the salt-sensitive variety under saline conditions. Under alkaline stress and salt-alkaline stress, the relative expression levels of the genes GhSOS1, GhNHX1 and GhAKT1 in the salt-tolerant variety were significantly higher than that in the salt-sensitive variety. These results suggest that this salt-tolerant variety of cotton has an internal mechanism to maintain ionic homeostasis.
棉花对盐胁迫的敏感性取决于基因型和盐的类型。了解不同盐胁迫下离子稳态的机制，对于提高棉花在盐胁迫条件下的性能是必要的。本试验采用盆栽试验，设置 3 种盐胁迫（NaCl+Na2SO4、碱性胁迫（Na2CO3+NaHCO3）和盐碱性胁迫（NaCl+Na2SO4+Na2CO3+NaHCO3）以及 2 个棉花品种（耐盐品种 L24 和盐敏感品种 G1），研究了棉花品种在不同盐胁迫下的生长、离子浓度和 Na+转运相关基因的表达。结果表明，盐碱性胁迫对棉花生长的抑制作用大于单独的盐胁迫或碱性胁迫。碱性胁迫下根/茎比显著低于盐胁迫。在不同盐胁迫下，耐盐棉花品种叶片、茎和根中的 Na 浓度低于盐敏感品种，而 K 浓度高于盐敏感品种。对于盐敏感棉花品种，盐胁迫显著抑制 P 的吸收和 P、K、Mg 的运输，而碱性胁迫和盐碱性胁迫显著抑制 P、K、Ca、Mg 和 Zn 的吸收和运输。在不同盐胁迫下，耐盐品种的大部分元素都积累在叶片和茎中。这表明在盐胁迫条件下，耐盐品种比盐敏感品种具有更强的离子转运能力。在碱性胁迫和盐碱性胁迫下，耐盐品种中 GhSOS1、GhNHX1 和 GhAKT1 基因的相对表达水平显著高于盐敏感品种。这些结果表明，该耐盐棉花品种具有维持离子稳态的内在机制。
