玉米灌浆期籽粒应答干旱胁迫的差异蛋白质组分析

Differential Proteomics Analysis of Maize Grain in Response to Drought Stress During Filling Stage

为了揭示玉米灌浆期抗旱调节机制,从蛋白质水平分析玉米灌浆期籽粒应答干旱胁迫的差异表达蛋白的特征和功能进行研究。本研究以耐旱性弱玉米自交系‘掖478’和耐旱性强玉米自交系‘黄早四’为试验材料,采用同位素标记相对定量(iTRAQ)技术,对干旱胁迫下差异表达蛋白进行比较研究。结果表明,2种玉米自交系在正常供水和干旱胁迫下共鉴定到蛋白4273个,干旱胁迫相比正常供水处理,‘掖478’差异表达蛋白有63个,包括上调10个,下调53个‘;黄早四’差异表达蛋白有438个,包括上调200个,下调238个。对差异表达蛋白进行基因本论(GO)注释表明,蛋白参与较多的生物过程是细胞过程、代谢过程、单一生物过程和刺激应答;细胞组件类别中蛋白主要分布在细胞、细胞部分、细胞器和大分子复合物;分子功能类别蛋白主要具备催化活性、绑定和结构分子活性。对刺激应答和生物调控差异表达蛋白分析发现,蛋白酶水解抑制剂、抗氧化酶、脱水蛋白、脱落酸应答蛋白和类防御素等蛋白在耐旱性强玉米自交系中表达水平发生了显著改变,他们在玉米灌浆期籽粒响应干旱胁迫过程中发挥了重要作用。相比耐旱性弱玉米自交系,耐旱性强玉米自交系,体内更多蛋白发生了差异表达,它们的共同协作能更好地适应干旱胁迫。本研究结果为玉米抗旱分子育种提供了理论基础。

In order to reveal the regulation mechanism of drought resistance in maize grain filling stage,the characteristics and functions of differentially expressed proteins in maize grain responding to drought stress were analyzed at the protein level.In this study,drought-resistant maize inbred line’Ye478’and drought-sensitive maize inbred line’Huangzao4’were used as experimental materials to compare the differentially expressed proteins under drought stress by using isobaric tags for relative and absolute quantitation(iTRAQ).The results showed that 4273 proteins were identified in the two maize inbred lines under normal water supply and drought stress.Compared with normal water supply treatment,63 differentially expressed proteins in’Ye478’were up-regulated by 10 and down-regulated by 53,and 438 differentially expressed proteins in’Huangzao4’were up-regulated by 200 and down-regulated by 238.Gene Ontology(GO)annotations of differentially expressed proteins showed that proteins participate in biological process,including cellular process,metabolic process,single-organism process and response to stimulus;proteins in cell module categories were mainly distributed in cell,cell part,organelle and macromolecular complex;proteins in molecular functional categories had catalytic activity,binding and structural molecular activity.Analysis of differential expressed proteins of response to stimulus and biological regulation found that protease hydrolysis inhibitors,antioxidant enzymes,dehydration proteins,ABA-responsive and defensin-like proteins had changed significantly in drought-resistant maize inbred line,and they played important roles in response to drought stress during filling stage.Compared with the drought-sensitive of maize inbred lines,the drought-resistant of maize inbred lines had more differentially expressed proteins in vivo,and their cooperation could better adapt to drought stress.The results of this study provided a theoretical basis for molecular breeding of drought resistance in maize.