Department of Crop Genetics and Breeding, College of Agronomy, Hebei Agricultural University, Baoding 071001, China.
North China Key Laboratory for Crop Germplasm Resources of the Education Ministry, Hebei Agricultural University, Baoding 071001, China.
Int J Mol Sci. 2019 Jul 31;20(15):3743. doi: 10.3390/ijms20153743.
Despite recent scientific headway in deciphering maize ( L.) drought stress responses, the overall picture of key proteins and genes, pathways, and protein-protein interactions regulating maize filling-kernel drought tolerance is still fragmented. Yet, maize filling-kernel drought stress remains devastating and its study is critical for tolerance breeding. Here, through a comprehensive comparative proteomics analysis of filling-kernel proteomes of two contrasting (drought-tolerant YE8112 and drought-sensitive MO17) inbred lines, we report diverse but key molecular actors mediating drought tolerance in maize. Using isobaric tags for relative quantification approach, a total of 5175 differentially abundant proteins (DAPs) were identified from four experimental comparisons. By way of Venn diagram analysis, four critical sets of drought-responsive proteins were mined out and further analyzed by bioinformatics techniques. The YE8112-exclusive DAPs chiefly participated in pathways related to "protein processing in the endoplasmic reticulum" and "tryptophan metabolism", whereas MO17-exclusive DAPs were involved in "starch and sucrose metabolism" and "oxidative phosphorylation" pathways. Most notably, we report that YE8112 kernels were comparatively drought tolerant to MO17 kernels attributable to their redox post translational modifications and epigenetic regulation mechanisms, elevated expression of heat shock proteins, enriched energy metabolism and secondary metabolites biosynthesis, and up-regulated expression of seed storage proteins. Further, comparative physiological analysis and quantitative real time polymerase chain reaction results substantiated the proteomics findings. Our study presents an elaborate understanding of drought-responsive proteins and metabolic pathways mediating maize filling-kernel drought tolerance, and provides important candidate genes for subsequent functional validation.
尽管最近在破译玉米（L.）干旱胁迫响应方面取得了科学进展，但调节玉米灌浆期耐旱性的关键蛋白质和基因、途径以及蛋白质-蛋白质相互作用的整体情况仍然很零碎。然而，玉米灌浆期干旱胁迫仍然具有破坏性，对其进行研究对于耐旱性育种至关重要。在这里，我们通过对两个具有不同耐旱性的自交系（耐旱 YE8112 和耐旱 MO17）灌浆期蛋白质组进行全面的比较蛋白质组学分析，报告了调节玉米耐旱性的不同但关键的分子作用因子。使用相对定量同位素标记法，从四个实验比较中共鉴定出 5175 个差异丰度蛋白（DAP）。通过韦恩图分析，挖掘出了四组关键的干旱响应蛋白，并进一步通过生物信息学技术进行了分析。YE8112 特有的 DAP 主要参与与“内质网蛋白质加工”和“色氨酸代谢”相关的途径，而 MO17 特有的 DAP 则参与“淀粉和蔗糖代谢”和“氧化磷酸化”途径。值得注意的是，我们报告称，YE8112 籽粒相对耐旱，而 MO17 籽粒则不耐旱，这归因于其氧化后翻译修饰和表观遗传调控机制、热休克蛋白的高表达、丰富的能量代谢和次生代谢物生物合成以及种子贮藏蛋白的上调表达。此外，比较生理分析和定量实时聚合酶链反应结果证实了蛋白质组学的发现。我们的研究深入了解了调节玉米灌浆期耐旱性的干旱响应蛋白和代谢途径，并为随后的功能验证提供了重要的候选基因。
