title: ZmbZIP91 regulates expression of starch synthesis-related genes by binding to ACTCAT elements in their promoters.
abstract: Starch synthesis is a key process that influences crop yield and quality, though little is known about the regulation of this complex metabolic pathway. Here, we present the identification of ZmbZIP91 as a candidate regulator of starch synthesis via co-expression analysis in maize (Zea mays L.). ZmbZIP91 was strongly associated with the expression of starch synthesis genes. Reverse tanscription-PCR (RT-PCR) and RNA in situ hybridization indicated that ZmbZIP91 is highly expressed in maize endosperm, with less expression in leaves. Particle bombardment-mediated transient expression in maize endosperm and leaf protoplasts demonstrated that ZmbZIP91 could positively regulate the expression of starch synthesis genes in both leaves and endosperm. Additionally, the Arabidopsis mutant vip1 carried a mutation in a gene (VIP1) that is homologous to ZmbZIP91, displayed altered growth with less starch in leaves, and ZmbZIP91 was able to complement this phenotype, resulting in normal starch synthesis. A yeast one-hybrid experiment and EMSAs showed that ZmbZIP91 could directly bind to ACTCAT elements in the promoters of starch synthesis genes (pAGPS1, pSSI, pSSIIIa, and pISA1). These results demonstrate that ZmbZIP91 acts as a core regulatory factor in starch synthesis by binding to ACTCAT elements in the promoters of starch synthesis genes.
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Chen
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yi
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Cao
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Lanjie
authors.initials: L
authors.lastname: Zheng
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Qianling
authors.initials: Q
authors.lastname: Xiao
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Yangping
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Huang
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Yongbin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Xianbin
authors.initials: X
authors.lastname: Hou
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Tiandan
authors.initials: T
authors.lastname: Long
authors.affiliation: College of Life Science, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Life Science, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Hanmei
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Guowu
authors.initials: G
authors.lastname: Yu
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China yubihuang@sohu.com.
authors.forename: Yubi
authors.initials: Y
authors.lastname: Huang
mesh_terms: D056625:Endosperm / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding / Q000235:genetics; D011523:Protoplasts / Q000378:metabolism; D013213:Starch / Q000096:biosynthesis*; D003313:Zea mays / Q000196:embryology / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D013213:Starch
keywords: ACTCAT motif; ZmbZIP91.; co-expression; gene transcription; maize; starch synthesis