Overexpression of MtNAC33 enhances biomass yield and drought tolerance in alfalfa

作者：Ruijuan Yang, Ying Sun, Yan Zhao, Chen Bai, Yaling Liu, Jingzhe Sun, Zhaoming Wang, Yuan Feng, Xiaoshan Wang, Wenwen Liu, Chunxiang Fu · 发表于：Plant Biotechnology Journal · 年份：2025 · DOI：10.1111/pbi.14597 · 被引用次数：11 · 研究领域：Bioenergy crop production and management、Crop Yield and Soil Fertility、Genetics and Plant Breeding

Alfalfa (Medicago sativa L.), a highly valuable perennial forage legume, is extensively cultivated worldwide (Russelle, 2001). As global warming exacerbates evaporation rates, severe drought conditions, characterized by mud cracking, have increasingly affected alfalfa cultivation regions. Drought stress can decrease stomatal conductance, impair photosynthesis activity and induce reactive oxygen species (ROS) accumulation in Alfalfa plants. Therefore, it reduces alfalfa growth and accelerates flowering, leading to significant declines in biomass yield and forage quality. Previous studies have shown that the plant-specific NAC (NAM, ATAF1,2 and CUC2) transcription factors play crucial roles in plant response to diverse environmental stresses. For example, NACs are involved in cold response of tomato, salt tolerance of soybean and disease resistance of Arabidopsis. Recent studies have also highlighted that OsNAC120 and OsNAC016 regulated the balance between plant growth and drought tolerance by promoting gibberellin (GA) biosynthesis, brassinosteroid (BR) signalling and repressing abscisic acid (ABA)-mediated drought responses (Wu et al., 2022; Xie et al., 2024). These insights provide a framework for developing crop varieties with improved biomass yield under drought conditions. The Medicago truncatula NAC transcription factor MtNAC33 (Medtr3g096140), one member of the NAC2 subfamily, clusters phylogenetically with Arabidopsis NAC082 and NAC103 (Figure S1). Previous studies rev...