盐胁迫对燕麦叶片生理指标和差异蛋白组学的影响

为探讨盐胁迫对燕麦叶片生理指标及蛋白组的影响,对燕麦进行6d盐胁迫(摩尔浓度NaCl∶Na_2SO_4=1∶1)处理,测定CK与盐胁迫燕麦叶片MDA含量,SOD、POD活性与游离脯氨酸含量,并运用Label-Free技术分析叶片差异表达蛋白质。结果表明,盐胁迫下燕麦叶片MDA含量、SOD、POD活性分别较对照降低了16.7%、23.4%和21.2%,游离脯氨酸较对照升高1.12%;满足P-value≤0.05, ratio2的差异蛋白76个(51个蛋白上调表达, 25个蛋白下调表达);通过GO注释得到27个差异蛋白显著富集16个代谢路径,其中氧化还原过程为33.9%,level3统计富集的生物学过程有氧气结合和氧化还原酶活性;运用KEGG注释得到22个差异蛋白显著富集10个生化代谢途径,主要表现在内质网中的蛋白质加工、长寿调节途径、抗原处理和呈现、雌激素信号通路4个过程;STRING蛋白质互作网络显示21个差异蛋白中涉及翻译后修饰、蛋白质周转、分子伴侣功能的有10个,且HSP70(F2DYT5)和HSP90(F4Y589)可能在盐胁迫燕麦幼苗的调控中发挥重要作用。

Effects of salt stress on physiological indexes and differential proteomics of oat leaf

MDA content, SOD and POD activities, free proline content of oat leaves were determined under salt stress (molar NaCl: Na₂SO₄=1:1), and the differentially expressed proteins in leaves were analyzed by using Label-Free technique. The results showed that the activities of MDA, SOD and POD in oat leaves decreased by 16.7%, 23.4%, and 21.2% respectively, and free proline content increased by 1.12% compared with the control. There were 76 differential proteins with P-value ≤ 0.05 and ratio > 2 (51 proteins up-regulated and 25 proteins down-regulated). The GO annotation indicated that 27 differential proteins were significantly enriched in 16 metabolic pathways, of which the oxidation-reduction process was 33.9%. The biological processes of level 3 statistical enrichment were oxygen binding and oxidoreductase activity. Twenty-two differential proteins were obtained using KEGG annotation, which was significantly enriched in 10 biochemical metabolic pathways, mainly including four processes: protein processing in endoplasmic reticulum, longevity regulating pathway-multiple species, antigen processing and presentation, estrogen signaling pathway. The STRING protein interaction network showed that 10 of the 21 differential proteins involved in post-translational modification, protein turnover, and molecular chaperone function, and HSP70 and HSP90 interacted with the most core proteins of the whole network. It is speculated that the up-regulation of core protein is one of the reasons for the salt tolerance of oats.