Zheng Peizhong, Allen William B, Roesler Keith, Williams Mark E, Zhang Shirong, Li Jiming, Glassman Kimberly, Ranch Jerry, Nubel Douglas, Solawetz William, Bhattramakki Dinakar, Llaca Victor, Deschamps Stéphane, Zhong Gan-Yuan, Tarczynski Mitchell C, Shen Bo
Pioneer Hi-Bred International Inc., A DuPont Company, 7300 NW 62nd Avenue, PO Box 1004, Johnston, Iowa 50131, USA.
Nat Genet. 2008 Mar;40(3):367-72. doi: 10.1038/ng.85. Epub 2008 Feb 17.
Plant oil is an important renewable resource for biodiesel production and for dietary consumption by humans and livestock. Through genetic mapping of the oil trait in plants, studies have reported multiple quantitative trait loci (QTLs) with small effects, but the molecular basis of oil QTLs remains largely unknown. Here we show that a high-oil QTL (qHO6) affecting maize seed oil and oleic-acid contents encodes an acyl-CoA:diacylglycerol acyltransferase (DGAT1-2), which catalyzes the final step of oil synthesis. We further show that a phenylalanine insertion in DGAT1-2 at position 469 (F469) is responsible for the increased oil and oleic-acid contents. The DGAT1-2 allele with F469 is ancestral, whereas the allele without F469 is a more recent mutant selected by domestication or breeding. Ectopic expression of the high-oil DGAT1-2 allele increases oil and oleic-acid contents by up to 41% and 107%, respectively. This work provides insights into the molecular basis of natural variation of oil and oleic-acid contents in plants and highlights DGAT as a promising target for increasing oil and oleic-acid contents in other crops.
植物油是生物柴油生产以及人类和牲畜膳食消费的重要可再生资源。通过对植物油脂性状的遗传定位，研究报告了多个效应较小的数量性状位点（QTL），但油脂QTL的分子基础仍 largely未知。在此，我们表明一个影响玉米种子油和油酸含量的高油QTL（qHO6）编码一种酰基辅酶A：二酰甘油酰基转移酶（DGAT1-2），它催化油脂合成的最后一步。我们进一步表明，DGAT1-2在第469位（F469）的苯丙氨酸插入导致了油和油酸含量的增加。具有F469的DGAT1-2等位基因是祖先型的，而没有F469的等位基因是通过驯化或育种选择的较新突变体。高油DGAT1-2等位基因的异位表达分别使油和油酸含量最多增加41%和107%。这项工作为植物中油和油酸含量自然变异的分子基础提供了见解，并突出了DGAT作为增加其他作物油和油酸含量的一个有前景的靶点。
