College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, United Kingdom (F.F.).
Department of Crop Genetics (C.M.O., S.P.) and Department of Computational and Systems Biology (M.T.), John Innes Centre, Norwich, NR4 7UH, United Kingdom.
Plant Physiol. 2017 May;174(1):276-283. doi: 10.1104/pp.16.01556. Epub 2017 Mar 14.
The mother plant plays an important dynamic role in the control of dormancy of her progeny seed in response to environmental signals. In order to further understand the mechanisms by which this dormancy control takes place in Arabidopsis (), we conducted a forward genetic screen to isolate mutants that fail to enter dormancy in response to variation in temperature during seed set. We show that, for the first of these mutants, designated , the maternal allele is required for entry into strongly dormant states and that mutants show seed phenotypes shown previously to be associated with the loss of suberin in the seed. We identify as an allele of , an ATP-binding cassette transporter-encoding gene required for the transport of fatty acids during suberin deposition, and show that further suberin-deficient mutants have seed dormancy defects. Seed coat suberin composition is affected by temperature during seed maturation, but this response appears to be independent of ABCG20. We conclude that seed coat suberin is essential for seed dormancy imposition by low temperature and that the exclusion of oxygen and water from the seed by the suberin and tannin layers is important for dormancy imposition.
母株在控制其后代种子休眠方面起着重要的动态作用，以响应环境信号。为了进一步了解拟南芥中这种休眠控制的机制（），我们进行了正向遗传学筛选，以分离出在种子形成过程中温度变化时无法进入休眠的突变体。我们表明，对于第一个突变体，命名为 ，母本等位基因是进入强烈休眠状态所必需的，而 突变体表现出先前与种子中栓质丢失相关的种子表型。我们将 鉴定为 ，一种需要在栓质沉积过程中运输脂肪酸的 ATP 结合盒转运蛋白编码基因的等位基因，并表明进一步的栓质缺陷突变体具有种子休眠缺陷。种子被成熟过程中的温度影响，但这种反应似乎与 ABCG20 无关。我们得出结论，种子表皮栓质对于低温下种子休眠的施加是必不可少的，而栓质和单宁层将氧气和水分排除在种子之外对于休眠的施加是重要的。
