Wang Kaitong, Zhang Huanhuan, Yang Liang, Wei Han, Tang Xun, Zhang Ning, Si Huaijun
State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, 730070, China; College of Agronomy, Gansu Agricultural University, Lanzhou, 730070, China.
State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, 730070, China; College of Life Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China.
Plant Physiol Biochem. 2025 Aug 18;229(Pt A):110383. doi: 10.1016/j.plaphy.2025.110383.
Drought and salt stress are among the main factors affecting agricultural productivity, seriously influencing the growth, development and yield of potatoes. The mitogen-activated protein kinase (MAPK) cascade is highly conserved in signal transduction under abiotic stress. However, studies on the expression patterns of the mitogen-activated protein kinase kinase (MAPKKs) gene under drought and salt stress are limited, and there is a lack of functional verification of it in supporting potato plant growth. The expression pattern of StMAPKK family genes in potato plants was analyzed by qRT-PCR method. StMAPKK1 was identified as a drought-tolerant and salt-tolerant gene, which showed significant upregulation under drought and salt (200 mM NaCl) stress. Subcellular localization shows that it is expressed in the nucleus and cell membrane. To verify its function, we constructed overexpressing and knocking down expression plants. Under drought and salt stress, the transgenic lines overexpressing StMAPKK1 showed increased antioxidant enzyme activity, increased proline content and decreased malondialdehyde content, indicating that the redox homeostasis in the overexpressing plants was improved. The expression of key antioxidant response genes (StSOD1, StSOD2, StPOD12, StPOD47, StPOD66, StCAT1 and StCAT2) and drought and salt-tolerant StMAPK genes (StMAPK3 and StMAPK10) in overexpressed plants was upregulated. The enzyme defense system and MAPK cascade amplification signal were enhanced, improving drought and salt tolerance. Overexpressed plants also enhanced photosynthesis, stomata closed, and reduced water transpiration. Confirm the positive role of StMAPKK1 in drought resistance and salt tolerance. On the contrary, the results in the knocking down expression plants were opposite to those in the overexpression plants. These findings highlight that StMAPKK1, as a key factor in the MAPK cascade reaction, plays a positive regulatory role in the drought and salt tolerance of potatoes.
干旱和盐胁迫是影响农业生产力的主要因素，严重影响马铃薯的生长、发育和产量。丝裂原活化蛋白激酶（MAPK）级联在非生物胁迫下的信号转导中高度保守。然而，关于丝裂原活化蛋白激酶激酶（MAPKKs）基因在干旱和盐胁迫下的表达模式的研究有限，并且缺乏其在支持马铃薯植株生长方面的功能验证。采用qRT-PCR方法分析了马铃薯植株中StMAPKK家族基因的表达模式。StMAPKK1被鉴定为耐旱和耐盐基因，在干旱和盐（200 mM NaCl）胁迫下显著上调。亚细胞定位表明它在细胞核和细胞膜中表达。为了验证其功能，构建了过表达和敲低表达植株。在干旱和盐胁迫下，过表达StMAPKK1的转基因株系表现出抗氧化酶活性增加、脯氨酸含量增加和丙二醛含量降低，表明过表达植株中的氧化还原稳态得到改善。过表达植株中关键抗氧化反应基因（StSOD1、StSOD2、StPOD12、StPOD47、StPOD66、StCAT1和StCAT2）以及耐旱和耐盐StMAPK基因（StMAPK3和StMAPK10）的表达上调。酶防御系统和MAPK级联放大信号增强，提高了耐旱性和耐盐性。过表达植株还增强了光合作用，气孔关闭，减少了水分蒸腾。证实了StMAPKK1在抗旱和耐盐方面的积极作用。相反，敲低表达植株中的结果与过表达植株中的结果相反。这些发现突出表明，StMAPKK1作为MAPK级联反应中的关键因子，在马铃薯的耐旱和耐盐性中发挥着积极的调节作用。
