摘要
为了揭示玉米种子衰老机理,本研究以“郑单958”玉米杂交种为材料,研究了人工老化处理(温度45℃﹑相对湿度100%)后种子活力﹑种胚O_(2)^(-)产生和积累﹑种胚ATP含量和ATP合成酶活性,并用反转录阻断-双引物扩增法分析种胚及不同器官(盾片﹑胚根和胚芽)ATP合成酶亚基mRNA的完整性。结果表明,人工老化处理后,玉米种子的萌发率和胚根生长速率下降;种胚生活力降低;种子呼吸强度减弱。种胚O_(2)^(-)产生速率在老化3d时达到高峰,随后下降;胚根和胚芽O_(2)^(-)产生速率和含量显著增加;种胚ATP含量和ATP合成酶活性降低。ATP合成酶ε亚基和γ亚基的mRNA完整性先升高后降低;δ亚基mRNA的完整性没有明显变化;α亚基和β亚基mRNA的完整性则持续降低;胚根和胚芽ATP合成酶亚基mRNA的损伤程度大于盾片。说明在老化过程中胚根和胚芽ROS产生和积累,导致ATP合成酶亚基mRNA不同程度的损伤,ATP合成酶活性降低,ATP含量减少,造成萌发过程种胚供能不足,这可能是导致玉米种子衰老的重要原因之一。
In this study,hybrid maize(Zea mays L.)cultivar‘Zhengdan 958’seeds were used as materials to reveal the mechanism of seed aging.After artificial aging treatment(45℃,100%relative humidity),the seed vigor,O_(2)^(-) production,ATP content,and ATP synthase activity of seed embryo were investigated,and the integrity of ATP synthase subunit mRNAs in seed embryo and different organs(scutellum,radicle,and plumule)was analyzed by the reverse transcription blocking and double-primer amplification method.The results showed that the germination rate and radicle growth rate of maize seeds decreased,the viability of embryo decreased and the respiration intensity of seeds decreased after artificial aging treatment.The O_(2)^(-) production rate in embryo reached the peak on the 3rd day of aging treatment,and then decreased,the O_(2)^(-) production rate and content in radicle and plumule increased significantly.The ATP content and ATP synthase activity in embryo decreased.The mRNA integrity of ATP synthaseε-subunit andγ-subunit increased first and then decreased.The mRNA integrity ofδ-subunit did not change significantly.The m RNA integrity ofα-subunit andβ-subunit decreased continuously in artificial aging treatment.The damage degree of m RNA integrity of ATP synthase subunits in radicle and plumule was much greater than that in scutellum.These results revealed that the production and accumulation of ROS in radicle and plumule could lead to different degrees of damage to ATP synthase subunit mRNAs and the activity of ATP synthase and the content of ATP in embryo decreased,which resulted in the lack of energy supply during germination,and this maybe one of the major factors causing maize seed aging.
作者
王天波
赫文学
张峻铭
吕伟增
梁雨欢
卢洋
王雨露
谷丰序
宋词
陈军营
WANG Tian-Bo;HE Wen-Xue;ZHANG Jun-Ming;LYU Wei-Zeng;LIANG Yu-Huan;LU Yang;WANG Yu-Lu;GU Feng-Xu;SONG Ci;CHEN Jun-Ying(College of Agronomy,Henan Agricultural University,Zhengzhou 450046,Henan,China)
出处
《作物学报》
CAS
CSCD
北大核心
2022年第8期1996-2006,共11页
Acta Agronomica Sinica
基金
国家自然科学基金项目(31971998,31571761)资助。
