title: Up-regulating the abscisic acid inactivation gene ZmABA8ox1b contributes to seed germination heterosis by promoting cell expansion.
abstract: Heterosis has been widely used in agriculture, but the underlying molecular principles are still largely unknown. During seed germination, we observed that maize (Zea mays) hybrid B73/Mo17 was less sensitive than its parental inbred lines to exogenous abscisic acid (ABA), and endogenous ABA content in hybrid embryos decreased more rapidly than in the parental inbred lines. ZmABA8ox1b, an ABA inactivation gene, was consistently more highly up-regulated in hybrid B73/Mo17 than in its parental inbred lines at early stages of seed germination. Moreover, ectopic expression of ZmABA8ox1b obviously promoted seed germination in Arabidopsis Remarkably, microscopic observation revealed that cell expansion played a major role in the ABA-mediated maize seed germination heterosis, which could be attributed to the altered expression of cell wall-related genes.
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Xinye
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Hongjian
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Sui
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Fang
authors.affiliation: National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jinfang
authors.initials: J
authors.lastname: Chu
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Xin
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China.
authors.forename: Chaojie
authors.initials: C
authors.lastname: Xie
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing 100193, China.
authors.forename: Yirong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China qxsun@cau.edu.cn nizf@cau.edu.cn.
authors.forename: Qixin
authors.initials: Q
authors.lastname: Sun
authors.affiliation: State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China National Plant Gene Research Center (Beijing), Beijing 100193, China qxsun@cau.edu.cn nizf@cau.edu.cn.
authors.forename: Zhongfu
authors.initials: Z
authors.lastname: Ni
mesh_terms: D000040:Abscisic Acid / Q000235:genetics / Q000502:physiology*; D017360:Arabidopsis; D049108:Cell Enlargement; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant / Q000235:genetics* / Q000502:physiology; D018525:Germination / Q000235:genetics* / Q000502:physiology; D006823:Hybrid Vigor / Q000235:genetics* / Q000502:physiology; D030821:Plants, Genetically Modified; D012639:Seeds / Q000254:growth & development; D015854:Up-Regulation; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development / Q000502:physiology
chemical_list: D000040:Abscisic Acid
keywords: Abscisic acid; ZmABA8ox1b.; gene expression; heterosis; maize; seed germination