Gresset Sebastian, Westermeier Peter, Rademacher Svenja, Ouzunova Milena, Presterl Thomas, Westhoff Peter, Schön Chris-Carolin
Plant Breeding, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany.
Plant Physiol. 2014 Jan;164(1):131-43. doi: 10.1104/pp.113.224816. Epub 2013 Nov 26.
In plants with C4 photosynthesis, physiological mechanisms underlying variation in stable carbon isotope discrimination (Δ(13)C) are largely unknown, and genetic components influencing Δ(13)C have not been described. We analyzed a maize (Zea mays) introgression library derived from two elite parents to investigate whether Δ(13)C is under genetic control in this C4 species. High-density genotyping with the Illumina MaizeSNP50 Bead Chip was used for a detailed structural characterization of 89 introgression lines. Phenotypic analyses were conducted in the field and in the greenhouse for kernel Δ(13)C as well as plant developmental and photosynthesis-related traits. Highly heritable significant genetic variation for Δ(13)C was detected under field and greenhouse conditions. For several introgression library lines, Δ(13)C values consistently differed from the recurrent parent within and across the two phenotyping platforms. Δ(13)C was significantly associated with 22 out of 164 analyzed genomic regions, indicating a complex genetic architecture of Δ(13)C. The five genomic regions with the largest effects were located on chromosomes 1, 2, 6, 7, and 9 and explained 55% of the phenotypic variation for Δ(13)C. Plant development stage had no effect on Δ(13)C expression, as phenotypic as well as genotypic correlations between Δ(13)C, flowering time, and plant height were not significant. To our knowledge, this is the first study demonstrating Δ(13)C to be under polygenic control in the C4 species maize.
在具有C4光合作用的植物中，稳定碳同位素分馏（Δ(13)C）变化背后的生理机制很大程度上未知，且尚未描述影响Δ(13)C的遗传成分。我们分析了一个源自两个优良亲本的玉米（Zea mays）渗入系文库，以研究在这种C4物种中Δ(13)C是否受遗传控制。使用Illumina MaizeSNP50 Bead芯片进行高密度基因分型，对89个渗入系进行详细的结构表征。在田间和温室中对籽粒Δ(13)C以及植物发育和光合作用相关性状进行表型分析。在田间和温室条件下均检测到Δ(13)C具有高度可遗传的显著遗传变异。对于几个渗入系文库品系，在两个表型分析平台内和平台间，其Δ(13)C值始终与轮回亲本不同。在164个分析的基因组区域中，有22个与Δ(13)C显著相关，表明Δ(13)C具有复杂的遗传结构。影响最大的五个基因组区域位于第1、2、6、7和9号染色体上，解释了Δ(13)C表型变异的55%。植物发育阶段对Δ(13)C表达没有影响，因为Δ(13)C、开花时间和株高之间的表型及基因型相关性均不显著。据我们所知，这是第一项证明在C4物种玉米中Δ(13)C受多基因控制的研究。
