紫花首蓿低温响应机制的转录组学分析

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Abstract： Alfalfa （Medicago sativa L.）is a crucial legume forage crop in temperate regions.However， when cultivated in high-latitude regions，chilling injury during spring regrowth stage frequently leads to delayed regeneration and suppressed growth，ultimately reducing both yield and forage quality. To explore the molecular mechanisms of alfalfa to low-temperature stress，we used the cold-tolerant cultivar Longmu 806 as research material.Using a combination of physicochemical analysis and transcriptome sequencing，we analyzed physiological indicators and differentially expressed genes（DEGs）under 4∘C low-temperature treatment over different time periods.A total of 8101 DEGs were identified，and enrichment analysis revealed six metabolic pathways significantly associated with low-temperature stress.Weighted co-expression network analysis （WGCNA）was employed to dissect the molecular mechanisms of alfalfa's response to low-temperature stress， revealing that MYB-related family genes may playa critical role in alfalfacold resistance.Enrichment analysis of DEGsin the'Meblue'module further identified12 cold-resistance-related DEGs from the tricarboxylic acid （TCA）cycle and glycolysis/gluconeogenesis pathway.This study provides new insights into the cold resistance mechanisms of alfalfa and offers theoretical support for molecular breeding of cold-tolerant alfalfa varieties.

Key words： alfalfa; cold resistance; physiological response;transcriptome sequencing

紫花苜蓿（MedicagosativaL.）是高生物量、高蛋白的优质豆科牧草，广泛种植于全球各地，尤其在中国东北、西北等北方寒冷干旱地区[1]。（剩余18749字）