冬凌草甲素对拟南芥种子萌发和幼苗生长的化感作用

Allelopathy of Oridonin on Seed Germination and Seedling Growth of Arabidopsis thaliana

以拟南芥为供试材料,研究了二萜化合物冬凌草甲素(oridonin)对拟南芥种子萌发、幼苗生长及生理特性的化感作用。结果表明:(1)各浓度冬凌草甲素处理均降低了拟南芥种子的发芽率、发芽势、发芽指数和种子活力指数;至最终萌发时间,120μmol/L冬凌草甲素处理的种子发芽率、发芽势和发芽指数、种子活力指数分别为对照的87.76%、70.37%、83.19%、27.72%,说明高浓度的冬凌草甲素对拟南芥种子发芽率、发芽势、发芽指数和种子活力指数均有显著抑制作用,且对种子活力指数的影响最为显著。(2)冬凌草甲素处理后培养拟南芥幼苗2周,60μmol/L冬凌草甲素处理的拟南芥根甚至出现侧根不生长的现象;120μmol/L冬凌草甲素处理的幼苗主根长度比对照组降低了79.05%,其鲜重、干重和相对含水量分别降为对照的58.41%、63.33%和93.91%。(3)不同浓度和时间的冬凌草甲素处理整体上显著促进了拟南芥幼苗体内渗透调节物质可溶性蛋白和脯氨酸的积累。研究发现,冬凌草甲素对拟南芥种子萌发及生长表现出不同程度的化感抑制作用,该抑制作用与冬凌草甲素的处理浓度及处理时间均密切相关;拟南芥幼苗能通过增加自身渗透调节物质积累在一定程度上缓解这种抑制作用。

Using Arabidopsis thaliana as material,we studied the allelopathy potential of the diterpene compound oridonin on the seed germination,growth and physiological reaction of A.thaliana seedlings.The results showed that:(1)oridonin treatment reduced A.thaliana seed germination rate,germination potential,germination index and seed vigor index;until the final germination time,the germination rate,germination potential and germination index were87.76%,70.37%and83.19%,respectively in120μmol/L oridonin treatment,the seed vigor index was only27.72%of the control.It showed that oridonin in higher concentration had significant inhibitory effects on the seed germination rate,germination potential,germination index and seed vigor index.(2)After two weeks culture,the lateral roots were inhibited totally in60μmol/L oridonin treatment.And the seedling primary root lengths decreased by79.05%,while the fresh weights,dry weights and relative water contents were reduced to58.41%,63.33%and93.91%,respectively in120μmol/L oridonin treatment.(3)The accumulation of osmotic regulators,soluble proteins and proline in A.thaliana seedlings were also overall promoted by oridonin at different concentrations and treating time.The study presented here confirmed that oridonin had inhibitory effect on seed germination and seedling growth of A.thaliana.And this allelopathy effect was closely related with both oridonin concentration and treatment time;Arabidopsis thaliana seedlings could alleviate this inhibition to a certain extent by increasing the accumulation of their own osmotic adjustment substances.