title: Overexpression of the autophagy-related gene SiATG8a from foxtail millet (Setaria italica L.) confers tolerance to both nitrogen starvation and drought stress in Arabidopsis.
abstract: Autophagy is an evolutionarily conserved biological process in all eukaryotes for the degradation of intracellular components for nutrient recycling. Autophagy is known to be involved in responses to low nitrogen stress in Arabidopsis. Foxtail millet has strong abiotic stress resistance to both low nutrient and drought stress. However, to date, there have only been a few genes reported to be related with abiotic stress resistance in foxtail millet. In this study, we identified an autophagy-related gene, SiATG8a, from foxtail millet. SiATG8a is mainly expressed in stems and its expression was dramatically induced by drought stress and nitrogen starvation treatments. SiATG8a was localized in the membrane and cytoplasm of foxtail millet. Overexpression of SiATG8a in Arabidopsis conferred tolerance to both nitrogen starvation and to drought stress. Under nitrogen starvation conditions, the SiATG8a transgenic plants had larger root and leaf areas and accumulated more total nitrogen than wild-type plants. The transgenic plants had lower total protein concentrations than did the WT plants. Under drought stress, the SiATG8a transgenic plants had higher survival rates, chlorophyll content, and proline content, but had lower MDA content than wild type plants. Taken together, our results represent the first identified case where overexpression of autophagy related gene can simultaneously improve plant resistance to low nitrogen and drought stresses. These findings implicate plant autophagy in plant stress responses to low nitrogen and drought and should be helpful in efforts to improve stresses resistance to nitrogen starvation and drought of crops by genetic transformation.
authors.affiliation: Key Laboratory of Molecular Cytogenetics and Genetic Breeding of Heilongjiang Province, College of Life Science and Technology, Harbin Normal University, Harbin, Heilongjiang 150025, China.
authors.forename: Wei-wei
authors.initials: WW
authors.lastname: Li
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.affiliation: Guizhou Institute of Prataculture, Gui Academy of Agricultural Sciences, Guiyang, Guizhou 550006, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhong
authors.affiliation: Key Laboratory of Molecular Cytogenetics and Genetic Breeding of Heilongjiang Province, College of Life Science and Technology, Harbin Normal University, Harbin, Heilongjiang 150025, China.
authors.forename: Jia-ming
authors.initials: JM
authors.lastname: Liu
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Zhao-shi
authors.initials: ZS
authors.lastname: Xu
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Lian-cheng
authors.initials: LC
authors.lastname: Li
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yong-Bin
authors.initials: YB
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Molecular Cytogenetics and Genetic Breeding of Heilongjiang Province, College of Life Science and Technology, Harbin Normal University, Harbin, Heilongjiang 150025, China. Electronic address: kaku3008@126.com.
authors.forename: Chang-Hong
authors.initials: CH
authors.lastname: Guo
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: mayouzhi@caas.cn.
authors.forename: You-Zhi
authors.initials: YZ
authors.lastname: Ma
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D001343:Autophagy / Q000502:physiology; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D024861:Genetic Enhancement / Q000379:methods; D009584:Nitrogen / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000502:physiology; D032983:Setaria Plant / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*; D014018:Tissue Distribution; D015854:Up-Regulation / Q000502:physiology
chemical_list: D010940:Plant Proteins; D009584:Nitrogen
keywords: Autophagy; Drought; Foxtail millet; Function analysis; Nitrogen starvation