College of Agronomy, Anhui Agricultural University, Hefei 230036, China.
Jiangsu Collaborative Innovation Centre for Modern Crop Production, Nanjing 210095, China.
Int J Mol Sci. 2024 Oct 27;25(21):11542. doi: 10.3390/ijms252111542.
The low-temperature stress (LTS) in spring results in tremendous yield loss in wheat production, and the application of potassium dihydrogen phosphate (KHPO) can alleviate stress-induced damage. However, the underlying effect of spraying KHPO on the physiological characteristics of wheat flag leaves under spring LTS remains unclear. In this study, we investigated the effect of spraying KHPO on flag leaf physiological traits and yield under spring LTS, including treatments at 15 °C and spraying HO (CK), treatment at -4 °C and spraying HO (LT1), and treatment at -4 °C and spraying KHPO (LT2). The results showed that spraying KHPO significantly increased the activities of the superoxide dismutase (SOD), the peroxidase (POD), and the catalase (CAT), and reduced malondialdehyde (MDA) content in the flag leaves. Compared to LT1, the SOD, POD, and CAT activities in the flag leaves of the Yangnong19 (YN19) and Xinmai26 (XM26) via LT2 increased by 5.5%, 10.9%, and 3.9%, and 5.4%, 9.2%, and 4.4%, respectively, and the MDA content of the YN19 and XM26 decreased by 10.5% and 9.1%, respectively, at 0-12 d after low temperature treatment (DALTT). Spraying KHPO appreciably alleviated damage to the leaf cell morphology and tissue integrity, and increased the accumulation of proline and soluble protein, the chlorophyll content, and the activities of Ribulose-1,5-bisphosphate carboxylase and phosphoenolpyruvate carboxykinase. The net photosynthetic rate in the flag leaves of the YN19 and XM26 via LT2 increased by 37.9% and 35.9%, respectively, at 0-12 DALTT, compared to LT1. Moreover, spraying KHPO reduced the yield loss rate of the YN19 and XM26 by 13.06% and 16.72%, respectively. The present study demonstrates that spraying KHPO can enhance wheat resistance to spring LTS and maintain the photosynthetic capacity of flag leaves, alleviating the negative effects of LTS on grain yield.
春季低温胁迫（LTS）会导致小麦产量大幅损失，而喷施磷酸二氢钾（KHPO）可以缓解胁迫诱导的损伤。然而，喷施 KHPO 对春季 LTS 下小麦旗叶生理特性的潜在影响尚不清楚。本研究探讨了喷施 KHPO 对春季 LTS 下小麦旗叶生理特性和产量的影响，包括 15°C 处理且喷施去离子水（HO）（CK）、-4°C 处理且喷施 HO（LT1）和-4°C 处理且喷施 KHPO（LT2）的处理。结果表明，喷施 KHPO 显著提高了旗叶中超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性，降低了丙二醛（MDA）的含量。与 LT1 相比，LT2 处理的扬麦 19（YN19）和新麦 26（XM26）旗叶的 SOD、POD 和 CAT 活性分别提高了 5.5%、10.9%和 3.9%和 5.4%、9.2%和 4.4%，MDA 含量分别降低了 10.5%和 9.1%，低温处理后 0-12 天（DALTT）。喷施 KHPO 明显减轻了低温对叶片细胞形态和组织完整性的破坏，增加了脯氨酸和可溶性蛋白的积累、叶绿素含量、以及核酮糖-1,5-二磷酸羧化酶和磷酸烯醇丙酮酸羧激酶的活性。LT2 处理的 YN19 和 XM26 旗叶的净光合速率分别比 LT1 增加了 37.9%和 35.9%，低温处理后 0-12 天（DALTT）。此外，喷施 KHPO 使 YN19 和 XM26 的产量损失率分别降低了 13.06%和 16.72%。本研究表明，喷施 KHPO 可以增强小麦对春季 LTS 的抗性，维持旗叶的光合能力，减轻 LTS 对粒重的负面影响。
