烟草种子后熟对GA和ABA代谢与信号基因表达及萌发的影响  

Effects of Seed After-ripening on GA and ABA Metabolism,Signal Gene Expression and Germination in Tobacco

作　　者：王尧 李振华 彭忠华[1] Wang Yao;Li Zhenhua;Peng Zhonghua(College of Agriculture,Guizhou University,Guiyang,550025;Guizhou Subcenter of National Wheat Improvement Center,Guiyang,550025)

机构地区：[1]贵州大学农学院,贵阳550025 [2]国家小麦改良中心贵州分中心,贵阳550025

出　　处：《分子植物育种》2021年第7期2312-2319,共8页Molecular Plant Breeding

基　　金：国家自然科学基金项目(31860420;32060512);贵州省科技计划项目(黔科合平台人才[2018]5781号);贵州省自然科学基金项目(黔科合基础[2019]1069);贵州大学引进人才科研项目(贵大人基合字[2018]37号)共同资助。

摘　　要：为了探索适宜的烟草种子后熟条件及了解其作用机理,本研究以‘K326’新采收烟草种子作为对照(CK),比较了恒温25℃、自然变温下后熟一个月及后熟两个月时期种子中GA和ABA代谢与信号基因表达差异。结果表明,新采收烟草种子存在光休眠,后熟有利于打破光休眠;自然变温较恒温25℃处理更有利于加速种子后熟;随着后熟时间的延长,不仅种子萌发率提高,而且萌发速度也加快。种子后熟过程中,自然变温处理NCED6的相对表达量均低于恒温25℃处理。无论常温还是变温处理,种子后熟两个月后GA3ox2和CYP707A1的相对表达量较后熟一个月显著升高,而GA2ox2、ABI3、XTH2和TOC1显著降低。综上所述,在后熟过程ABA代谢和信号被抑制,而GA合成和信号被激发,从而加速种子后熟和促进其萌发。本研究结果为后熟作用释放烟草种子光休眠的现象提供理论依据。In order to explore the appropriate conditions for tobacco seed after ripening and understand its mechanism of action,this study took fresh harvested tobacco seeds’K326’as the control(CK),and compared the differences in GA and ABA metabolism and signal gene expression in the seeds after ripening for one month and two months after ripening under a constant temperature of 25℃and a natural temperature variation.The results showed that fresh harvested tobacco seeds were photodormant,and the after-ripening was beneficial to break the photodormancy.Compared with constant temperature of 25℃treatment,natural temperature variation treatment is more beneficial to accelerate seed after-ripening.The germination rate and germination speed were increased with the prolongation of after-ripening time.During seed after-ripening,the expression level of NCED6 under natural temperature variation was lower than that under constant temperature of 25℃.The expression levels of GA3 ox2 and CYP707 A1 in two months after-ripening seeds were significantly higher than that in one month after ripening seeds,while the expression levels of GA2 ox2,ABI3,XTH2 and TOC1 were significantly lower than that at1 month after-ripening.In summary,ABA metabolism and signals are inhibited in the after-ripening process,while GA synthesis and signals are stimulated,thus accelerating seed after-ripening and promoting germination.This study provides a theoretical basis for the photodormancy of tobacco seeds released by after ripening.

关 键 词：后熟 光休眠 种子萌发 脱落酸 赤霉素 

分 类 号：S572[农业科学—烟草工业]