DELAY OF GERMINATION1 (DOG1) regulates both seed dormancy and flowering time through microRNA pathways
DELAY OF GERMINATION1 (DOG1) regulates both seed dormancy and flowering time through microRNA pathways
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DOI：
10.1073/pnas.1600558113
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发表时间：
2016-04-12
影响因子：
11.1
通讯作者：
Bradford, Kent J.
中科院分区：
文献类型：
--
作者：
Huo, Heqiang;Wei, Shouhui;Bradford, Kent J.
种子萌发和开花是植物生命周期中两个重要的发育过程，受遗传和环境因素的协调调节，使植物的建立和繁殖与季节因素相匹配。延迟发芽1基因（DELAY OF GERMINATION1, DOG1）参与调节种子对温度的休眠，并在遗传上与不同拟南芥品种和地点的多效开花表型相关。本研究表明，DOG1可以通过影响microrna (mirna) miR156和miR172的水平来调节莴苣（Lactuca sativa, Ls）和拟南芥的种子休眠和开花时间。在莴苣中，抑制LsDOG1的表达可以使种子在高温下萌发，促进种子提前开花，同时降低miR156和增加miR172的水平。在拟南芥中，miR156基因的过度表达导致miR156水平升高，从而增强了种子的休眠和延迟开花。这些表型效应，以及MIR156转录物向MIR156的转化，在DOG1功能缺失的突变植物中，尤其是在种子中受到损害。MIR172的过表达减少了拟南芥种子的休眠，促进了其提前开花，对开花的影响需要功能性的DOG1。当DOG1突变或表达减少时，拟南芥和莴苣干种子中与miRNA加工相关的几个基因的转录水平持续降低；相反，在DOG1功能获得突变体中，这些基因的转录水平升高。我们的研究结果揭示了植物生命周期中两个关键发育阶段之间通过DOG1-miR156-miR172相互作用的未知联系。
Seed germination and flowering, two critical developmental transitions in plant life cycles, are coordinately regulated by genetic and environmental factors to match plant establishment and reproduction to seasonal cues. The DELAY OF GERMINATION1 (DOG1) gene is involved in regulating seed dormancy in response to temperature and has also been associated genetically with pleiotropic flowering phenotypes across diverse Arabidopsis thaliana accessions and locations. Here we show that DOG1 can regulate seed dormancy and flowering times in lettuce (Lactuca sativa, Ls) and Arabidopsis through an influence on levels of microRNAs (miRNAs) miR156 and miR172. In lettuce, suppression of LsDOG1 expression enabled seed germination at high temperature and promoted early flowering in association with reduced miR156 and increased miR172 levels. In Arabidopsis, higher miR156 levels resulting from overexpression of the MIR156 gene enhanced seed dormancy and delayed flowering. These phenotypic effects, as well as conversion of MIR156 transcripts to miR156, were compromised in DOG1 loss-of-function mutant plants, especially in seeds. Overexpression of MIR172 reduced seed dormancy and promoted early flowering in Arabidopsis, and the effect on flowering required functional DOG1. Transcript levels of several genes associated with miRNA processing were consistently lower in dry seeds of Arabidopsis and lettuce when DOG1 was mutated or its expression was reduced; in contrast, transcript levels of these geneswere elevated in a DOG1 gain-of-function mutant. Our results reveal a previously unknown linkage between two critical developmental phase transitions in the plant life cycle through a DOG1-miR156-miR172 interaction.