单 位：
State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, Gansu, Chin;State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, Gansu, China
摘 要：
Alfalfa is the most widely cultivated perennial legume forage crop worldwide. Drought is one of the major environmental factors influencing alfalfa productivity. However, the molecular mechanisms underlying alfalfa responses to drought stress are still largely unknown. This study identified a drought-inducible gene of unknown function, designated as Medicago sativa DROUGHT-INDUCED UNKNOWN PROTEIN 1 (MsDIUP1). MsDIUP1 was localized to the nucleus, chloroplast, and plasma membranes. Overexpression of MsDIUP1 in Arabidopsis resulted in increased tolerance to drought, with higher seed germination, root length, fresh weight, and survival rate than in wild-type (WT) plants. Consistently, analysis of MsDIUP1 over-expression (OE) alfalfa plants revealed that MsDIUP1 also increased tolerance to drought stress, accompanied by physiological changes including reduced malondialdehyde (MDA) con-tent and increased osmoprotectants accumulation (free proline and soluble sugar), relative to the WT. In contrast, disruption of MsDIUP1 expression by RNA interference (RNAi) in alfalfa resulted in a drought -hypersensitive phenotype, with a lower chlorophyll content, higher MDA content, and less osmoprotec-tants accumulation than that of the WT. Transcript profiling of alfalfa WT, OE, and RNAi plants during drought stress showed differential responses for genes involved in stress signaling, antioxidant defense, and osmotic adjustment. Taken together, these results reveal a positive role for MsDIUP1 in regulating drought tolerance.(c) 2022 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
