College of Bioengineering, Sichuan University of Science and Engineering, Yibin, 644000, China.
BMC Genomics. 2024 Aug 27;25(1):806. doi: 10.1186/s12864-024-10702-7.
Drought stress restricts the growth, distribution and productivity of alfalfa (Medicago sativa L.). In order to study the response differences of alfalfa cultivars to drought stress, we previously carried out physiological and molecular comparative analysis on two alfalfa varieties with contrasting drought resistance (relatively drought-tolerant Longdong and drought-sensitive Algonquin). However, the differences in proteomic factors of the two varieties in response to drought stress still need to be further studied. Therefore, TMT-based quantitative proteomic analysis was performed using leaf tissues of the two alfalfa cultivars to identify and uncover differentially abundant proteins (DAPs).
In total, 677 DAPs were identified in Algonquin and 277 in Longdong under drought stress. Subsequently, we conducted various bioinformatics analysis on these DAPs, including subcellular location, functional classification and biological pathway enrichment. The first two main COG functional categories of DAPs in both alfalfa varieties after drought stress were 'Translation, ribosomal structure and biogenesis' and 'Posttranslational modification, protein turnover, chaperones'. According to KEGG database, the DAPs of the two alfalfa cultivars after drought treatment were differentially enriched in different biological pathways. The DAPs from Algonquin were enriched in 'photosynthesis' and 'ribosome'. The pathways of 'linoleic acid metabolism', 'protein processing in endoplasmic reticulum' and 'RNA transport' in Longdong were significantly enriched. Finally, we found significant differences in DAP enrichment and expression patterns between Longdong and Algonquin in glycolysis/glycogenesis, TCA cycle, photosynthesis, protein biosynthesis, flavonoid and isoflavonoid biosynthesis, and plant-pathogen interaction pathway after drought treatment.
The differences of DAPs involved in various metabolic pathways may explain the differences in the resistance of the two varieties to drought stress. These DAPs can be used as candidate proteins for molecular breeding of alfalfa to cultivate new germplasm with more drought tolerance to adapt to unfavorable environments.
干旱胁迫限制了紫花苜蓿（Medicago sativa L.）的生长、分布和生产力。为了研究不同苜蓿品种对干旱胁迫的响应差异，我们之前对两个具有不同抗旱性的苜蓿品种（相对抗旱的陇东和抗旱性敏感的阿尔冈昆）进行了生理和分子比较分析。然而，这两个品种在响应干旱胁迫时的蛋白质组学因素差异仍需进一步研究。因此，我们使用两种苜蓿品种的叶片组织进行了基于 TMT 的定量蛋白质组学分析，以鉴定和揭示差异丰度蛋白（DAP）。
在干旱胁迫下，阿尔冈昆共鉴定出 677 个 DAP，陇东鉴定出 277 个 DAP。随后，我们对这些 DAP 进行了各种生物信息学分析，包括亚细胞定位、功能分类和生物途径富集。干旱胁迫后，两种苜蓿品种的 DAP 前两个主要 COG 功能类别是“翻译、核糖体结构和生物发生”和“翻译后修饰、蛋白质周转、伴侣”。根据 KEGG 数据库，干旱处理后两种苜蓿品种的 DAP 在不同的生物途径中差异富集。阿尔冈昆的 DAP 富集在“光合作用”和“核糖体”中。陇东的“亚麻酸代谢”、“内质网蛋白加工”和“RNA 转运”途径明显富集。最后，我们发现干旱处理后，陇东和阿尔冈昆在糖酵解/糖异生、三羧酸循环、光合作用、蛋白质生物合成、类黄酮和异黄酮生物合成以及植物-病原体相互作用途径中，DAP 富集和表达模式存在显著差异。
参与各种代谢途径的 DAP 的差异可能解释了两个品种对干旱胁迫的抗性差异。这些 DAP 可以作为苜蓿分子育种的候选蛋白，培育具有更高抗旱性的新种质，以适应不利环境。
