Plant Physiol:华中农业大学严建兵课题组解析玉米籽粒代谢遗传基
近日，《Plant Pysiology》杂志在线发表了华中农业大学作物遗传改良国家重点实验室玉米团队严建兵教授课题组的研究论文，题为“Combining quantitative GENEtics approaches withregulatory network analysis to dissect the complex metabolism of the maizekernel”。研究以两个玉米重组自交系群体为基础，结合数量遗传学和基因表达网络分析方法解析了成熟籽粒中155种代谢物质含量变异的遗传基础。严建兵教授课题组的刘海军、周杨、肖英杰、金敏、杨宁、潘青春，罗杰教授课题组的李东，马普所的Takayuki Toghe, Alisdair Fernie等多位老师和同学共同参与该研究工作，闻玮玮博士为本研究第一作者兼通讯作者。
尽管玉米是全世界最重要的作物之一，但对玉米籽粒中有益微量代谢成分的挖掘研究尚不深入。剖析玉米籽粒中各种代谢成分的遗传基础，挖掘功能基因，不仅对增加玉米籽粒中除淀粉，油份等熟知的大量营养成分之外的其它微量营养成分，提高经济和市场附加值具有重要意义，而且为植物代谢的生化和分子机理研究提供了新的信息和思路。本研究利用液质联用技术分析玉米成熟籽粒中的代谢谱，继而用基于重组自交系的连锁分析定位到与155个代谢物质含量相关联的882个数量性状位点(QTL)。这155个物质涵盖了氨基酸、脂肪酸、维生素和类黄酮等几大类代谢物。在对每个QTL区间内基因进行注释后，研究团队结合生化知识和已发表文献找到了大量与代谢物含量关联的候选基因，并进一步以已知代谢途径为出发点，结合基因表达量数据发散网络，捕获与该代谢途径关联的新的候选基因，部分基因与QTL定位所发掘的基因重合。研究成果丰富了我们对玉米籽粒代谢调控的认识，也为玉米品质性状的进一步遗传改良提供了有价值的参考。相关阅读：PLoS Genetics:华中农业大学张祖新课题组发表玉米产量性状遗传研究论文
原文链接：
Combining quantitative genetics approaches with regulatory network analysis to dissect the complex metabolism of the maize kernel
原文摘要：
Metabolic quantitative trait loci (QTL) studies have allowed us to better understand the genetic architecture underlying naturally occurred plant metabolic variance. Here we use two recombinant inbred line (RIL) populations to dissect the genetic architecture of natural variation of 155 metabolites measured in the mature maize kernel. Overall, linkage mapping identified 882 metabolic QTL in both RIL populations across two environments with an average of 2.1 QTL per metabolite. A large number of metabolic QTL (>65%) were identified with moderate effects (R2=2.1-10%) while a small portion (<35%) showed major effects (R2>10%). Epistatic interactions between these identified loci were detected for more than 30% metabolites (with proportion of phenotypic variance ranging from 1.6 to 37.8%), implying that genetic epistasis is not negligible in determining metabolic variation. Totally, 57 QTL were validated by our previous genome-wide association study (GWAS) on the same metabolites that provided clues for exploring the underlying genes. A gene regulatory network associated with the flavonoid metabolic pathway was constructed based on the transcriptional variations of 28,769 genes in kernels (15 days after pollination) of 368 maize inbred lines. A large number of genes (34/58) in this network overlapped with previously defined genes controlled by maize Pericarp color1 whilst three of them were identified here within QTL intervals for multiple flavonoids. The deeply characterized RIL populations, elucidation of metabolic phenotypes and the identification of candidate genes lay the foundation for maize quality improvement.
作者：严建兵
