Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695.
National Laboratory of Genomics for Biodiversity 36821, Irapuato, Mexico.
Proc Natl Acad Sci U S A. 2022 Jul 5;119(27):e2100036119. doi: 10.1073/pnas.2100036119. Epub 2022 Jun 30.
Native Americans domesticated maize ( ssp. ) from lowland teosinte ( ssp. in the warm Mexican southwest and brought it to the highlands of Mexico and South America where it was exposed to lower temperatures that imposed strong selection on flowering time. Phospholipids are important metabolites in plant responses to low-temperature and phosphorus availability and have been suggested to influence flowering time. Here, we combined linkage mapping with genome scans to identify (), a gene that encodes a phospholipase A1 enzyme, as a major driver of phospholipid variation in highland maize. Common garden experiments demonstrated strong genotype-by-environment interactions associated with variation at with the highland allele leading to higher fitness in highlands, possibly by hastening flowering. The highland maize variant resulted in impaired function of the encoded protein due to a polymorphism in a highly conserved sequence. A meta-analysis across HPC1 orthologs indicated a strong association between the identity of the amino acid at this position and optimal growth in prokaryotes. Mutagenesis of via genome editing validated its role in regulating phospholipid metabolism. Finally, we showed that the highland allele entered cultivated maize by introgression from the wild highland teosinte ssp. and has been maintained in maize breeding lines from the Northern United States, Canada, and Europe. Thus, introgressed from teosinte underlies a large metabolic QTL that modulates phosphatidylcholine levels and has an adaptive effect at least in part via induction of early flowering time.
美洲原住民在墨西哥温暖的西南部低地驯化了大刍草（ Zea mays subsp. ），并将其带到墨西哥和南美洲的高地，在那里，它面临着更低的温度，这对开花时间施加了强烈的选择压力。磷脂是植物对低温和磷供应响应的重要代谢物，并被认为会影响开花时间。在这里，我们将连锁作图与全基因组扫描相结合，鉴定出（），一个编码磷脂酶 A1 酶的基因，是高地玉米中磷脂变异的主要驱动因素。共同田间实验表明，与 基因座上的变异相关的基因型与环境的强烈互作，高地 等位基因导致在高地上更高的适应性，可能通过加速开花。高地玉米 变体由于高度保守序列中的一个多态性导致编码蛋白的功能受损。对 HPC1 同源物的荟萃分析表明，该位置氨基酸的身份与原核生物中的最佳生长之间存在很强的关联。通过基因组编辑对 进行诱变验证了其在调节磷脂代谢中的作用。最后，我们表明，高地 等位基因是通过从野生高地大刍草（ Zea mays subsp. mexicana ）的杂交进入栽培玉米的，并且在美国北部、加拿大和欧洲的玉米育种种系中得到了维持。因此，从大刍草中引入的 是一个很大的代谢 QTL 的基础，该 QTL 调节磷脂酰胆碱水平，并通过诱导早期开花时间至少部分地产生适应性效应。
