PNAS:农科院植保所魏守辉研究组等揭示基因通过小RNA途径调控种
2016年3月28日， 国际著名学术期刊《美国国家科学院院刊》杂志在线发表了中国农科院植物保护研究所杂草创新研究组魏守辉博士与美国美国加州大学戴维斯分校科学家合作的题为“DELAY OF GERMINATION1 (DOG1) regulates both seed dormancy and flowering time through microRNA pathways”的研究成果。研究人员在种子休眠遗传调控方面取得新的研究进展，论文称发现休眠相关基因通过小RNA途径调控种子休眠和开花的新机制。
选择适宜的季节进行种子萌发和开花结实是植物对环境的重要适应性，尽管有遗传证据表明调控种子休眠和开花的基因间存在关联，但其协同调控机制尚不明晰。通过研究发现，延迟萌发基因DOG1(DELAY OF GERMINATION1)不仅参与调控拟南芥和生菜种子的休眠深度，确定种子萌发的适宜时机，而且能影响植株的开花时间。进一步研究证实，DOG1基因主要通过影响micrornA的生成来调控植物生长周期中的关键相变(休眠?萌发、营养生长?生殖生长)。该研究结果对揭示种子休眠和开花对环境协同适应的分子遗传学机制以及杂草绿色防控具有重要的理论和应用价值，是植物适应和感知气候变化、调控自身发育状态的重要发现。
图:基因通过小rna途径调控种子休眠和开花机制
原文链接：
DELAY OF GERMINATION1 (DOG1) regulates both seed dormancy and flowering time through microRNA pathways
原文摘要：
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 MIR156gene enhanced seed dormancy and delayed flowering. These phenotypic effects, as well as conversion ofMIR156 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 genes were 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.
作者：魏守辉
