高温胁迫下紫花苜蓿品种胞质蛋白质变化的比较

摘要

To investigate the effects of heat stress on cytoplasmic proteins among different alfalfa cultivars,an experiment was carried with Algonguin,Sardi 10 and Deqin under 35/30℃(day/ night,heat stress)and 25/20℃(dayight,control),and photochemical efficiency was measured as the heat stress tolerance index.The experiment results showed that Fv/Fm decreased most in Algonguin,least in Sardi 10 and Deqin was in-between.This results indicated that Algonguin was sensitive to heat,Sardi 10 was tolerant to heat and Deqin was moderate.The decline in cytoplasmic proteins content was significant in Sardi 10 until 28d under heat stress,while the decline was detected on 21days in both Deqin and Algonguin.55-kDa and 32-kDa proteins degraded under heat stress in all three cultivars;however,Algonguin presented more severe protein degradation than Deqin and Sardi 10 did.Heat stress induced expression of certain heat shock proteins(HSPs)(25-kDa,22-kDa and 18-kDa)in the cytoplasm in three tested cultivars;nevertheless,Sardi 10 had a stronger induced expression of 25-kDa and 22-kDa proteins than Algonguin and Deqin did.In addition,a specific expression of 20kDa cytoplasmic protein was occurred in Deqin.%为探明高温胁迫对不同品种紫花苜蓿胞质蛋白质的影响,以35/30℃(白天/夜间)为高温,25/20℃(白天/夜间)为对照,以光化学效率为高温胁迫耐受力的指标,比较阿尔冈金(Algonguin)、赛迪10(Sardi 10)和德钦(Deqin)3个紫花苜蓿品种胞质蛋白质的变化.结果表明:高温胁迫下,阿尔冈金的光化学效率Fv/Fm下降最快,赛迪10下降最慢；阿尔冈金是热敏型,赛迪10是耐热型,德钦的耐热性中等.在胁迫第28d,赛迪10的胞质蛋白质含量显著下降,而德钦和阿尔冈金的胞质蛋白质含量下降发生在胁迫第21d.3个品种的55kDa和32kDa胞质蛋白质在高温胁迫下均发生降解,阿尔冈金降解最为严重.3个品种在高温胁迫下表达25kDa、22kDa和18kDa胞质蛋白质的程度不同,其中25kDa和22kDa在赛迪10中表达量较其他两个品种大.此外,德钦紫花苜蓿在高温胁迫下具有特异的20kDa胞质蛋白质表达.