title: Transcriptome analysis of near-isogenic lines provides molecular insights into starch biosynthesis in maize kernel.
abstract: Starch is the major component in maize kernels, providing a stable carbohydrate source for humans and livestock as well as raw material for the biofuel industry. Increasing maize kernel starch content will help meet industry demands and has the potential to increase overall yields. We developed a pair of maize near-isogenic lines (NILs) with different alleles for a starch quantitative trait locus on chromosome 3 (qHS3), resulting in different kernel starch content. To investigate the candidate genes for qHS3 and elucidate their effects on starch metabolism, RNA-Seq was performed for the developing kernels of the NILs at 14 and 21 d after pollination (DAP). Analysis of genomic and transcriptomic data identified 76 genes with nonsynonymous single nucleotide polymorphisms and 384 differentially expressed genes (DEGs) in the introgressed fragment, including a hexokinase gene, ZmHXK3a, which catalyzes the conversion of glucose to glucose-6-phosphate and may play a key role in starch metabolism. The expression pattern of all DEGs in starch metabolism shows that altered expression of the candidate genes for qHS3 promoted starch synthesis, with positive consequences for kernel starch content. These results expand the current understanding of starch biosynthesis and accumulation in maize kernels and provide potential candidate genes to increase starch content.
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Yingni
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: DuPont Pioneer, 200 Powder Mill Road, Wilmington, DE 19880, USA.
authors.forename: Shawn
authors.initials: S
authors.lastname: Thatcher
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.|College of Agronomy, Northwest Agricultural and Forest University, Yang Ling 712100, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Wang
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Beatty
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131, USA.
authors.forename: Gina
authors.initials: G
authors.lastname: Zastrow-Hayes
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Li
authors.affiliation: DuPont Pioneer, 200 Powder Mill Road, Wilmington, DE 19880, USA.
authors.forename: Bailin
authors.initials: B
authors.lastname: Li
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yang
mesh_terms: D020869:Gene Expression Profiling / Q000379:methods*; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D018745:Genome, Plant; D007178:Inbreeding; D015203:Reproducibility of Results; D012639:Seeds / Q000235:genetics*; D017423:Sequence Analysis, RNA; D013213:Starch / Q000096:biosynthesis*; D003313:Zea mays / Q000235:genetics*
chemical_list: D013213:Starch
keywords: Coexpression network; RNA-Seq; maize; quantitative trait loci; starch content