title: Identification of low Ca(2+) stress-induced embryo apoptosis response genes in Arachis hypogaea by SSH-associated library lift (SSHaLL).
abstract: Calcium is a universal signal in the regulation of wide aspects in biology, but few are known about the function of calcium in the control of early embryo development. Ca(2+) deficiency in soil induces early embryo abortion in peanut, producing empty pods, which is a general problem; however, the underlying mechanism remains unclear. In this study, embryo abortion was characterized to be caused by apoptosis marked with cell wall degradation. Using a method of SSH cDNA libraries associated with library lift (SSHaLL), 62 differentially expressed genes were isolated from young peanut embryos. These genes were classified to be stress responses, catabolic process, carbohydrate and lipid metabolism, embryo morphogenesis, regulation, etc. The cell retardation with cell wall degradation was caused by up-regulated cell wall hydrolases and down-regulated cellular synthases genes. HsfA4a, which was characterized to be important to embryo development, was significantly down-regulated under Ca(2+) -deficient conditions from 15 days after pegging (DAP) to 30 DAP. Two AhCYP707A4 genes, encoding abscisic acid (ABA) 8'-hydroxylases, key enzymes for ABA catabolism, were up-regulated by 21-fold under Ca(2+) -deficient conditions upstream of HsfA4a, reducing the ABA level in early embryos. Over-expression of AhCYP707A4 in Nicotiana benthamiana showed a phenotype of low ABA content with high numbers of aborted embryos, small pods and less seeds, which confirms that AhCYP707A4 is a key player in regulation of Ca(2+) deficiency-induced embryo abortion via ABA-mediated apoptosis. The results elucidated the mechanism of low Ca(2+) -induced embryo abortion and described the method for other fields of study.
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Tie Cheng
authors.initials: TC
authors.lastname: Cai
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Shuangbiao
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Yixiong
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Shiwei
authors.initials: S
authors.lastname: Ma
authors.affiliation: Cash Crops Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, China.
authors.forename: Ronghua
authors.initials: R
authors.lastname: Tang
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India.
authors.forename: Rajeev K
authors.initials: RK
authors.lastname: Varshney
authors.affiliation: Fujian Provincial Key Laboratory of Crop Molecular and Cell Biology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Weijian
authors.initials: W
authors.lastname: Zhuang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D010367:Arachis / Q000166:cytology / Q000187:drug effects / Q000196:embryology* / Q000235:genetics; D002118:Calcium / Q000494:pharmacology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D015723:Gene Library; D017343:Genes, Plant; D058977:Molecular Sequence Annotation; D009693:Nucleic Acid Hybridization / Q000379:methods*; D010641:Phenotype; D030821:Plants, Genetically Modified; D060888:Real-Time Polymerase Chain Reaction; D012639:Seeds / Q000166:cytology* / Q000187:drug effects; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D014026:Nicotiana / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D000040:Abscisic Acid; D003577:Cytochrome P-450 Enzyme System; D002118:Calcium
keywords: Arachis hypogaea; Ca2+ stress; Cyp707A4; SSHaLL; abscisic acid; embryo abortion