Urzinger Sebastian, Avramova Viktoriya, Frey Monika, Urbany Claude, Scheuermann Daniela, Presterl Thomas, Reuscher Stefan, Ernst Karin, Mayer Manfred, Marcon Caroline, Hochholdinger Frank, Brajkovic Sarah, Ordas Bernardo, Westhoff Peter, Ouzunova Milena, Schön Chris-Carolin
Plant Breeding, TUM School of Life Sciences, Technical University of Munich, Freising 85354, Germany.
Maize Breeding, KWS SAAT SE & Co. KGaA, Einbeck 37574, Germany.
Plant Physiol. 2024 Dec 24;197(1). doi: 10.1093/plphys/kiae670.
The sustainability of maize cultivation would benefit tremendously from early sowing, but is hampered by low temperatures during early development in temperate climates. We show that allelic variation within the gene encoding subunit M of the NADH-dehydrogenase-like (NDH) complex (ndhm1) in a European maize landrace affects several quantitative traits that are relevant during early development in cold climates through NDH-mediated cyclic electron transport around photosystem I, a process crucial for photosynthesis and photoprotection. Beginning with a genome-wide association study for maximum potential quantum yield of photosystem II in dark-adapted leaves (Fv/Fm), we capitalized on the large phenotypic effects of a hAT transposon insertion in ndhm1 on multiple quantitative traits (early plant height [EPH], Fv/Fm, chlorophyll content, and cold tolerance) caused by the reduced protein levels of NDHM and associated NDH components. Analysis of the ndhm1 native allelic series revealed a rare allele of ndhm1 that is associated with small albeit significant improvements of Fv/Fm, photosystem II efficiency in light-adapted leaves (ΦPSII), and EPH compared with common alleles. Our work showcases the extraction of favorable alleles from locally adapted landraces, offering an efficient strategy for broadening the genetic variation of elite germplasm by breeding or genome editing.
玉米种植的可持续性将从早播中极大受益，但在温带气候下，早期发育期间的低温会阻碍这一点。我们表明，欧洲玉米地方品种中编码NADH脱氢酶样（NDH）复合体亚基M的基因（ndhm1）内的等位基因变异，通过NDH介导的围绕光系统I的循环电子传递，影响了几个在寒冷气候下早期发育过程中相关的数量性状，这一过程对光合作用和光保护至关重要。从对暗适应叶片中光系统II的最大潜在量子产量（Fv/Fm）进行全基因组关联研究开始，我们利用了ndhm1中hAT转座子插入对多个数量性状（早期株高[EPH]；Fv/Fm、叶绿素含量和耐寒性）的巨大表型效应，这些效应是由NDHM和相关NDH组分的蛋白质水平降低引起的。对ndhm1天然等位基因系列的分析揭示了一个罕见的ndhm1等位基因，与常见等位基因相比，它与Fv/Fm、光适应叶片中的光系统II效率（ΦPSII）和EPH虽小但显著的改善相关。我们的工作展示了从地方适应的地方品种中提取有利等位基因，为通过育种或基因组编辑拓宽优良种质的遗传变异提供了一种有效策略。
