花生种子萌发过程中内源激素含量的变化

Content changes of endogenous hormones in peanut seeds during germination

种子的休眠和萌发是植物生活史重要的两个环节,植物激素在其中起到关键的调节作用。本研究利用ELISA方法测定了弱休眠性花生品种Chico(CC)和强休眠性丰花1号(FH1)花生种子在萌发过程不同部位中脱落酸(ABA)、赤霉素(GA3)、油菜素内酯(BR)和吲哚乙酸(IAA)的含量。结果表明,FH1新鲜收获种子和干种子中不同部位ABA含量水平明显高于CC;吸水萌发过程中,两品种子叶中ABA含量和ABA/GA3比例变化趋势呈现明显差异,但两品种整体ABA含量及ABA/GA3比例随吸胀降低。研究表明,ABA在检测的三个部位中均发挥作用。萌发中后期,两品种子叶中GA3含量上升,表明GA3主要在子叶发挥作用。两品种IAA及BR含量在种子萌发过程变化趋势一致,它们主要在胚轴及胚根发挥作用。新鲜种子中IAA含量较高,吸胀后呈“波浪型”变化趋势,总体维持明显低于新鲜收获的种子中的水平;且FH1中IAA含量水平明显低于CC品种。萌发过程中两品种BR含量整体呈上升趋势,FH1的BR含量明显高于CC种子。总之,不同品种间内源激素含量水平存在差异,FH1中较高的ABA水平与其较强的休眠性有关;萌发过程中GA3、BR的提高和较低的IAA水平促进胚轴伸长及胚根生长。

Seed dormancy and germination are two important traits in plant life cycle,in which plant hormones play key regulatory roles.In this study,the contents of abscisic acid(ABA),gibberellin(GA3),brassinolide(BR)and indole acetic acid(IAA)in the different seed parts of peanut varieties Chico(CC)with weaker dormancy and Fenghua 1(FH1)with stronger dormancy were detected by ELISA.The results showed that the ABA contents in the different parts of FH1 at freshly harvested and dry seed stages were significantly higher than those in CC;and the ABA contents and ABA/GA3 ratio in cotyledons(Co)of the two varieties showed significant differences,while the overall ABA content and ABA/GA3 ratio of the two varieties decreased with the duration of imbibition.It is indicated that ABA plays a role in all three sections tested.At the middle and late stages of germination,the GA3 content in the cotyledons of the two varieties increased,indicating that GA3 mainly plays a role in the cotyledons.The content changes of IAA and BR in the two cultivars had the similar trend during the process of germination,and they mainly played a role in the Hypocotyl and radicle(HR)section.The IAA content in fresh seeds was higher.After imbibition,the IAA content displayed the alteration of“wave type”curve,and as a whole,maintanted the lower level than that in resh narrested seeds;and in FH1 IAA contents of the three sections were lower than those in CC varieties.The BR contents of two cultivars presented an upward trend during germination,and which of FH1 was higher than that of CC seeds on the whole.In conclusion,there were differences in endogenous hormone levels among different cultivars.The higher ABA level in FH1 was related to its stronger dormancy.The enhanced GA3,BR level and lower IAA level during germination promoted the elongation of hypocotyl and the growth of radicle.