小麦经过适当高温锻炼可产生获得耐热性，为揭示其分子生物学机理，选取耐热品种邯6172和热敏感品种石新733，对34℃热锻炼和42℃高温胁迫条件下叶片2个热激蛋白基因和6个抗氧化酶基因转录表达进行了荧光定量分析，并测定了热致死时间。结果显示，34℃热锻炼可不同程度地提高耐热品种和热敏感品种叶片的热致死时间，42℃高温胁迫下耐热品种表现出更强耐热性。34℃热锻炼可诱导耐热品种热激蛋白 TaHsp70 和 TaHsp16.9 基因在不同时间点出现不同程度表达高峰，植株遭受高温胁迫时基因表达上调幅度更强于热敏感品种。34℃热锻炼，耐热品种和热敏感品种 Ta（Cu/Zn）SOD、TaMnSOD、TaApx1、TaApx4 和 TaApx5 的表达均呈现间歇性升高趋势，耐热品种的表达量高于热敏感品种，遭受高温胁迫时基因表达持续上升的幅度相对更大。比较出现峰值的时间，热激蛋白和抗氧化酶基因的表达均不晚于热致死时间。说明，热锻炼可诱导热激蛋白和相关酶类基因上调表达，共同调控小麦获得耐热性。不同小麦品种获得耐热性的程度和持续的时间均不同，热锻炼后获得耐热性强度越大，保持的时间越长，遭遇高温胁迫时耐热性越强。
Wheat seedlings can get heat tolerance after exposed to heat acclimation.In order to study the molecular mechanism,heat killing times of leaf were measured and genes expression of heat-shock proteins and antioxidant enzymes were analyzed by qRT-PCR after subjected to heat acclimation at 34℃ for 48 h then 42℃ for 12 h using heat-tolerance cultivar Han 6172 and heat-susceptible cultivar Shixin 733.Heat tolerance of two wheat cultivars were increased to different degrees after heat acclimation at 34℃ and became marked after subjected to 42℃,Han 6172 showed more stronger heat tolerance. TaHsp70 and TaHsp16.9 genes expression could be up-regulated with different degrees in heat-tolerance cultivar after heat acclimation at 34℃ too.Based on this,the genes expression were up-regulated stronger in heat-tolerance cultivar than in heat-susceptible cultivar when subjected to 42℃.Genes expression of Ta(Cu/Zn)SOD, TaMnSOD, TaApx1, TaApx4 and TaApx5 all could be up-regulated with different degrees in heat-tolerance cultivar after heat acclimation at 34℃,and most of their expression level were higher in heat-tolerance cultivar than that in heat-susceptible cultivar.When subjected to 42℃,gene expression of Ta(Cu/Zn)SOD, TaMnSOD, TaApx1 and TaApx4 were up-regulated more stronger in heat-tolerance cultivar than that in heat-susceptible cultivar.Compared to the time point of peak,all gene expression were not latter than that of heat killing time.Those results showed that genes of Hsp and antioxidant enzyme participated in regulating the acquisition of heat tolerance during heat acclimation in wheat seedlings.The acquired heat tolerance were different in different wheat cultivars,the more stronger of acquired heat tolerance after heat acclimation,the longer it can be maintained,and the stronger heat tolerance crop showed after subjected to lethan temperature.
[1] 封超年,郭文善,施劲松,等.小麦花后高温对籽粒胚乳细胞发育及粒重的影响[J].作物学报,2000,26(4):399-405.
[2] 王晨阳,郭天财,阎耀礼,等.花后短期高温胁迫对小麦叶片光合性能的影响[J].作物学报,2004,30(1):88-91.
[3] 郭天财,王晨阳,朱云集,等.后期高温对冬小麦根系及地上部衰老的影响[J].作物学报,1998,24(6):957-962.
[4] 李永庚,于振文,张秀杰,等.小麦灌浆期产量和品质对高温胁迫的响应[J].植物生态学报,2005,29(3):461-466.
[5] Stone P J,Gras P W,Nicolas M E.The influence of recovery temperature on the effects of a brief heat shock on wheat.III.grain protein composition and dough properties[J].Journal of Cereal Science,1997,25(2):129-141.
[6] 周人纲,樊志和,李晓芝.热诱导对细胞膜和相关酶活性的影响[J].作物学报,1995,21(5):568-572.
[7] 周人纲,樊志和,李晓芝,等.小麦的热激蛋白及耐热性的获得[J].华北农学报,1994,9(S1):75-79.
[8] 胡秀丽,李艳辉,杨海荣,等.叶片热激蛋白70提高干旱和热激诱导的玉米抗氧化能力[J].作物学报,2010,36(4):636-644.
[9] 郭秀林,李慧聪,刘子会,等.不同基因型小麦品种对热诱导的响应[J].麦类作物学报,2013,33(3):514-519.
[10] Wang X,Cai J,Jiang D,et al.Pre-anthesis high-temperature acclimation alleviates damage to the flag leaf caused by post-anthesis heat stress in wheat[J].Journal of Plant Physiology,2011,168(6):585-593.
[11] Molinier J,Ries G,Zipfel C, et al. Transgeneration memory of stress in plants[J].Nature,2006,442(716):1046-1049.
[12] 安艳秋,蔺瑞明,冯晶,等.小麦热激蛋白70基因分子克隆及其在植物防御和胁迫反应过程中的表达分析[J].分子植物育种,2011,9(4):402-409.
[13] Nakamoto H,Hiyama T.Heat-shock proteins and temperature stress[M]//Pessaralkli,M.(Ed),Handbook of Plant and Crop Stress.New York:Marcel Dekker,1999:399-416.
[14] 李国良,张红梅,周人纲.小麦胁迫相关蛋白Hsa32基因的克隆[J].华北农学报,2008,23(6):1-5.
[15] 郭虹霞,王创云,赵丽,等.小分子热激蛋白的研究进展[J].山西农业科学,2013,41(12):1421-1423.
[16] 陈小霞,李磊,牛洪斌,等.高温胁迫对不同小麦品种幼苗叶片中抗氧化酶活性的影响[J].河南农业科学,2008(12):38-40,58.
[17] 敬海霞,王晨阳,郭天财,等.花后高温胁迫对不同筋型小麦籽粒品质的影响[J].河南农业科学,2010(6):5-8.
[18] 牛洪斌,陈小霞,白润娥,等.小麦热激蛋白16.9 cDNA克隆及表达 J].麦类作物学报,2008,18(5):719-723.
[19] 姜春明,尹燕枰,刘霞,等.不同耐热性小麦品种旗叶膜脂过氧化和保护酶活性对花后高温胁迫的响应[J].作物学报,2007,33(1):143-148.
[20] 刘萍,郭文善,浦汉春,等.灌浆期高温对小麦剑叶抗氧化酶及膜脂过氧化的影响[J].中国农业科学,2005,38(12):2403-2407.
[21] Plaut Z,Butow B J,Blumenthal C S,et al.Transport of dry matter into developing wheat kernels and its contribution to grain yield under post-anthesis water deficit and elevated temperature[J].Field Crops Research,2004,86(213):185-198.
[22] Hays D B,Do J H,Mason R E,et al.Heat stress induced ethylene production in developing wheat grains induces kernel abortion and increased maturation in a susceptible cultivar[J].Plant Science,2007,172(6):1113-1123.
[23] Weng J,Nguyen H T.Differences in the heat-shock response between thermotolerant and thermsusceptible cultivars of hexaploid wheat[J].Theoretical and Applied Genetics,1992,84(718):941-946.
