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Houmiao Wang

Publications and source records attributed to Houmiao Wang.

2 recordsLinked to original sources

Integrating GWAS and Transcriptome Analysis Identifies Candidate Genes for Kernel Starch Quality Traits in Maize.

Maize (Zea mays L.) starch quality is a complex trait with significant implications for grain processing and industrial applications. However, the genetic basis underlying starch quality, particularly for gelatinization and thermodynamic properties, remains poorly understood. In this study, we evaluated 12 starch quality traits, including seven gelatinization characteristics, four thermodynamic traits, and kernel starch content (KSC) in a diverse panel of 335 maize inbred lines. Considerable phenotypic variation was observed for all traits. A total of 228 quantitative trait loci (QTLs) were significantly associated with 12 starch quality traits through genome-wide association studies (GWAS). By integrating a dynamic transcriptome analysis of two maize inbred lines with contrasting starch quality, we identified 60 candidate genes. One gene, waxy1, encoding a starch synthase, was found to be associated with enthalpy of gelatinization (ΔHgel) and pasting temperature (Ptemp). Six variants in waxy1 contributed to natural variation in ΔHgel and Ptemp, and a cost-effective InDel and two PARMS-based molecular markers were developed and validated in 144 maize inbred lines, enabling efficient marker-assisted selection. Our findings provide key genes and molecular markers for high-quality maize breeding with improved starch properties.

Zea mays

Natural variation in the cytokinin oxidase gene ZmCKX6 influences leaf morphology and yield-related traits in maize.

Leaf width (LW) is a critical determinant of maize architecture and yield. To uncover its genetic basis, we performed a genome-wide association study (GWAS) on 348 maize inbred lines and identified ZmCKX6, encoding cytokinin oxidase/dehydrogenase, as a key gene associated with LW. Natural variation in the ZmCKX6 promoter significantly influenced its expression levels, leading to differences in LW across various haplotypes. Functional validation using CRISPR/Cas9 revealed that ZmCKX6 knockout results in pleiotropic effects, including narrower leaves, reduced plant height, and decreased grain yield components. These phenotypes were accompanied by elevated levels of active cytokinins but reduced levels of auxin, gibberellins, and salicylic acid. Transcriptome analysis revealed a significant downregulation of photosynthesis-related genes, corresponding to reduced photosynthetic rates in knockout lines. Evolutionary analysis demonstrated that the allele associated with narrower leaves were preferentially selected during maize domestication and breeding. This study highlights the role of ZmCKX6 in modulating cytokinin homeostasis and its subsequent impact on multiple agronomic traits in maize, providing insights into the complex genetic control of plant architecture and yield. The identified natural variations could be valuable for marker-assisted selection aimed at optimizing plant architecture and improving yield.

Zea mays