文献类型： 外文期刊

作者： Zhang, Hongjiao ¹ ; Yao, Tongtong ¹ ; Zhang, Hongrui ¹ ; Zhang, Zhe ¹ ; Wang, Kexin ¹ ; Qi, Siyue ¹ ; He, Xuan ³ ; Xu, Zhiru ¹ ; Qin, Bo ¹ ; Zhang, Huihui ¹ ;

作者机构： 1.Northeast Forestry Univ, Coll Life Sci, Harbin 150040, Peoples R China

2.Northeast Forestry Univ, Key Lab Saline Alkali Vegetat Ecol Restorat, Minist Educ, Harbin 150040, Peoples R China

3.Northeast Agr Univ, Coll Agr, Harbin 150006, Peoples R China

4.Heilongjiang Acad Agr Sci, Crop Resources Inst, Harbin 150086, Peoples R China

关键词： Medicago sativa; Hormone; Photosynthesis; WGCNA; NaHCO3 stress

期刊名称：ENVIRONMENTAL AND EXPERIMENTAL BOTANY （ 影响因子：4.7； 五年影响因子：5.4 ）

ISSN： 0098-8472

年卷期： 2024 年 228 卷

页码：

收录情况： SCI

摘要： The physiological and molecular mechanisms underlying salt-alkali tolerance in Medicago sativa are of significant importance for the development of animal husbandry on salt-alkali lands and the restoration of vegetation in such areas. This study utilized salt-alkali tolerance Medicago sativa ' Zhaodong' (ZD) and salt-alkali sensitive variety M. sativa ' Zhongmu No.1 ' ' (ZM) as materials. Physiological analyses, transcriptomic sequencing, and hormone-targeted metabolomics techniques were employed to investigate the differential responses of the two alfalfa varieties to NaHCO3 3 stress in terms of morphology, photosynthetic functionality, and oxidative damage indicators. Additionally, weighted gene co-expression network analysis (WGCNA) was utilized to elucidate key mechanisms underlying salt-alkali tolerance in alfalfa. The results indicate that NaHCO3 3 stress leads to photosynthetic inhibition and oxidative damage in alfalfa leaves. Under NaHCO3 3 stress, PSI in alfalfa leaves exhibits higher stability compared to PSII. The salt-alkali tolerance alfalfa variety ZD demonstrates stronger tolerance compared to the salt-alkali sensitive variety ZM. Furthermore, differentially expressed genes (DEGs) between the two varieties under NaHCO3 3 stress are primarily enriched in KEGG pathways such as chlorophyll synthesis, photosynthesis, carbon fixation, and plant hormone synthesis and signaling. Weighted gene co-expression network analysis (WGCNA) was conducted based on physiological and transcriptomic data. Most differentially expressed genes (DEGs) in the top two modules with the highest correlation to physiological indicators such as photosynthesis are enriched in hormone synthesis and signal transduction pathways. Additionally, key transcription factors involved in hormone signal transduction were identified within these modules, such as MYC2 and ABI5, , which regulate jasmonic acid (JA) and abscisic acid (ABA) signaling, respectively. These findings suggest that plant hormone signaling may play a critical role in regulating salt-alkali tolerance in alfalfa. Further analysis was conducted on plant hormone levels and gene expression involved in biosynthesis and signal transduction processes. The results indicate that NaHCO3 3 stress leads to significant accumulation of ABA and JA content in alfalfa leaves. The biosynthesis and signal transduction pathways of ABA and JA are activated under NaHCO3 3 stress. Additionally, the salt-alkali tolerance alfalfa variety ZD exhibits a more sensitive response to ABA and JA signals compared to ZM. Salicylic acid (SA) shows a positive response to NaHCO3 3 stress only in the ZD variety, which may be one of the key reasons for its stronger salt-alkali tolerance. Under NaHCO3 3 stress, overall growth-promoting hormones (IAA, GA, CK) are downregulated in ZD but upregulated in ZM, indicating that the salt-alkali tolerance alfalfa variety ZD mainly regulates the balance between growth and resistance by modulating the ratio of growth-promoting and stress-related hormones in response to NaHCO3 3 stress. This study reveals that hormone signaling plays a key role in regulating the photosynthetic function of alfalfa in response to salt-alkali stress, which provides theoretical basis and clues for the molecular breeding of alfalfa for salt-alkali tolerance.