Zahoor Rizwan, Zhao Wenqing, Dong Haoran, Snider John L, Abid Muhammad, Iqbal Babar, Zhou Zhiguo
Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, PR China.
Department of Crop and Soil Sciences, University of Georgia, Tifton 31794, USA.
Plant Physiol Biochem. 2017 Oct;119:21-32. doi: 10.1016/j.plaphy.2017.08.011. Epub 2017 Aug 17.
To investigate whether potassium (K) application enhances the potential of cotton (Gossypium hirsutum L.) plants to maintain physiological functions during drought and recovery, low K-sensitive (Siza 3) and -tolerant (Simian 3) cotton cultivars were exposed to three K rates (0, 150, and 300 KO kg ha) and either well-watered conditions or severe drought stress followed by a recovery period. Under drought stress, cotton plants showed a substantial decline in leaf water potential, stomatal conductance, photosynthetic rate, and the maximum and actual quantum yield of PSII, resulting in greater non-photochemical quenching and lipid peroxidation as compared to well-watered plants. However, plants under K application not only showed less of a decline in these traits but also displayed greater potential to recover after rewatering as compared to the plants without K application. Plants receiving K application showed lower lipid peroxidation, higher antioxidant enzyme activities, and increased proline accumulation as compared to plants without K application. Significant relationships between rates of photosynthetic recovery and K application were observed. The cultivar Siza 3 exhibited a more positive response to K application than Simian 3. The results suggest that K application enhances the cotton plant's potential to maintain functionality under drought and facilitates recovery after rewatering.
为了研究施钾是否能增强棉花（陆地棉）植株在干旱及恢复过程中维持生理功能的潜力，将低钾敏感型（泗杂3号）和耐低钾型（泗棉3号）棉花品种分别设置三种施钾水平（0、150和300 kg K₂O ha⁻¹），并分别置于充分供水条件下或先经历严重干旱胁迫再进入恢复期的环境中。在干旱胁迫下，棉花植株的叶片水势、气孔导度、光合速率以及PSII的最大和实际量子产量均大幅下降，与充分供水的植株相比，导致非光化学猝灭增加和脂质过氧化加剧。然而，与未施钾的植株相比，施钾处理的植株不仅在这些性状上下降幅度较小，而且在复水后表现出更大的恢复潜力。与未施钾的植株相比，施钾处理的植株脂质过氧化程度较低，抗氧化酶活性较高，脯氨酸积累增加。观察到光合恢复速率与施钾之间存在显著关系。泗杂3号品种对施钾的反应比泗棉3号更为积极。结果表明，施钾增强了棉花植株在干旱条件下维持功能的潜力，并促进了复水后的恢复。
