1.烟台大学生命科学学院, 山东烟台264005;2.中国农业科学院作物科学研究所, 北京100081
研究方向为玉米矮秆基因定位,E-mail:enhuien@163.com
郑军,玉米分子育种,E-mail : zhengjun02@caas.cn
国家重点研发计划 (2023YFD1200500)
1.College of Life Sciences, Yantai University, Yantai 264005, Shandong;2.Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081
National Key Research and Development Program (2023YFD1200500)
玉米的株高是决定其产量和稳定性的关键因素之一。本研究旨在通过优化玉米株型来提高玉米的单产。本课题组在B73的诱变材料中发现了一个矮化突变体d309,该突变体通过连续自交得以稳定遗传。遗传分析揭示,d309突变体的表型受单一隐性基因控制。与B73自交系相比,d309突变体展现出显著降低的株高和缩短的节间。细胞学研究表明,d309突变体在第5和第6茎节间的细胞长度显著缩短。通过构建d309与PH6WC的F2分离群体,并运用BSR-seq技术,将突变位点定位在第3号染色体的3.47~17.47 Mb区间。进一步通过基因定位将突变位点定位于5-4和5-7两对分子标记之间,该区间内只有1个开放阅读框(Zm00001d039634),编码赤霉素3-氧化酶(GA3ox,gibberellin 3-oxidases),已被报道为Dwarf1。测序结果显示,d309突变体在Zm00001d039634基因CDS区存在单个核苷酸的突变,导致氨基酸序列改变。蛋白质结构预测表明,该突变位点位于Fe(II)2OGD(Iron 2-oxoglutarate dioxygenase)结构域内。通过外源施加赤霉素,d309突变体的矮化表型得到恢复,从而确认d309为一个赤霉素合成缺陷型突变体。此外,d309突变体与已报道的Dwarf1等位突变体在突变机制上存在差异,表明d309可能是Dwarf1基因的一个新等位基因。
Plant height is one of the key factors determining yield and stability in maize. This research aims to increase the individual yield of maize by optimizing the plant architecture. We have discovered a dwarf mutant, d309, in the mutagenized material of the maize variety B73, which was stably inherited through continuous selfing. Genetic analysis revealed that the phenotype of the d309 mutant is controlled by a single recessive gene. Compared to the B73 inbred line, the d309 mutant exhibited a significantly reduced plant height and shortened internodes. Cytological studies indicated that the cell length between the 5th and 6th internodes of the d309 mutant was significantly reduced. By constructing an F2 population from the cross of d309 and PH6WC and employing BSR-seq technology, the mutation site was mapped to an interval of 3.47-17.47 Mb on chromosome 3. Further gene mapping localized the mutation site between two molecular markers, 5-4 and 5-7, within which there is only one open reading frame(Zm00001d039634) encoding gibberellin 3-oxidases (GA3ox), which has been reported as Dwarf1. Sequencing results showed that the d309 mutant has a single nucleotide mutation in the CDS region of the Zm00001d039634 gene, leading to an amino acid sequence change. Protein structure prediction suggested that the mutation site is located within the Fe(II)2OGD (iron 2-oxoglutarate dioxygenase) domain. The dwarf phenotype of the d309 mutant was observed to be rescued upon exogenous application of gibberellins, thereby confirming d309 as a gibberellin biosynthesis-deficient mutant. Additionally, the d309 mutant differs from the reported Dwarf1 allelic mutants in its mutation mechanism, indicating that d309 is a new allelic variant of the Dwarf1 gene.
张恩会,李健,王逸茹,等.玉米矮化突变体