Seed dormancy is a dynamic state: variable responses to pre- and post-shedding environmental signals in seeds of contrasting Arabidopsis ecotypes
Seed dormancy is a dynamic state: variable responses to pre- and post-shedding environmental signals in seeds of contrasting Arabidopsis ecotypes
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DOI：
10.1017/s096025851500001x
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发表时间：
2015-06-01
影响因子：
2.1
通讯作者：
Finch-Savage, William E.
中科院分区：
文献类型：
--
作者：
Huang, Ziyue;Footitt, Hulya Olcer;Finch-Savage, William E.
种子已经进化成为一种高效的环境传感器，不仅对其盛行的环境做出反应，而且对其环境历史做出反应，以调节休眠和萌发的启动。在本工作中，我们模拟土壤种子库中的时间，研究了种子发育过程中的一些环境信号(温度、硝酸盐、光)在种子发育过程中、在脱落后的吸胀过程中以及在脱落后的长时间暴露期间对母株的联合影响。在不同的冬季(CVI、LER)和夏季(BUR)年度拟南芥生态型中，观察到了对这些环境的不同反应。结果表明，落叶前后的环境信号决定了生理休眠的深度，从而决定了种子萌发对周围环境的反应。种子在不同环境中的成熟度大大提高了种子对环境萌发条件反应的生态型差异。当种子没有收到发芽所需的全部环境信号并以干燥或吸水状态进入土壤种子库时，在脱落后反应会进一步变化。因此，由于种子休眠是一种动态状态，受制于种内对当地环境的适应，因此不容易定义物种的休眠特征。
Seeds have evolved to be highly efficient environmental sensors that respond not only to their prevailing environment, but also their environmental history, to regulate dormancy and the initiation of germination. In the present work we investigate the combined impact of a number of environmental signals (temperature, nitrate, light) during seed development on the mother plant, during post-shedding imbibition and during prolonged post-shedding exposure in both dry and imbibed states, simulating time in the soil seed bank. The differing response to these environments was observed in contrasting winter (Cvi, Ler) and summer (Bur) annual Arabidopsis ecotypes. Results presented show that environmental signals both pre- and post-shedding determine the depth of physiological dormancy and therefore the germination response to the ambient environment. The ecotype differences in seed response to ambient germination conditions are greatly enhanced by seed maturation in different environments. Further variation in response develops following shedding when seeds do not receive the full complement of environmental signals required for germination and enter the soil seed bank in either dry or imbibed states. Species seed dormancy characteristics cannot therefore be easily defined, as seed dormancy is a dynamic state subject to within-species adaptation to local environments.