title: Genome-Wide Identification of Soybean U-Box E3 Ubiquitin Ligases and Roles of GmPUB8 in Negative Regulation of Drought Stress Response in Arabidopsis.
abstract: Plant U-box (PUB) E3 ubiquitin ligases play important roles in hormone signaling pathways and response to abiotic stresses, but little is known about them in soybean, Glycine max. Here, we identified and characterized 125 PUB genes from the soybean genome, which were classified into eight groups according to their protein domains. Soybean PUB genes (GmPUB genes) are broadly expressed in many tissues and are a little more abundant in the roots than in the other tissues. Nine GmPUB genes, GmPUB1-GmPUB9, showed induced expression patterns by drought, and the expression of GmPUB8 was also induced by exogenous ABA and NaCl. GmPUB8 was localized to post-Golgi compartments, interacting with GmE2 protein as demonstrated by yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) experiments, and showed E3 ubiquitin ligase activity by in vitro ubiquitination assay. Heterogeneous overexpression of GmPUB8 in Arabidopsis showed decreased drought tolerance, enhanced sensitivity with respect to osmotic and salt stress inhibition of seed germination and seedling growth, and inhibited ABA- and mannitol-mediated stomatal closure. Eight drought stress-related genes were less induced in GmPUB8-overexpressing Arabidopsis after drought treatment compared with the wild type and the pub23 mutant. Taken together, our results suggested that GmPUB8 might negatively regulate plant response to drought stress. In addition, Y2H and BiFC showed that GmPUB8 interacted with soybean COL (CONSTANS LIKE) protein. GmPUB8-overexpressing Arabidopsis flowered earlier under middle- and short-day conditions but later under long-day conditions, indicating that GmPUB8 might regulate flowering time in the photoperiod pathway. This study helps us to understand the functions of PUB E3 ubiquitin ligases in soybean.
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Cong
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Zhong
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shouping
authors.initials: S
authors.lastname: Yang
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China yanli1@njau.edu.cn sri@njau.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: National Key Laboratory of Crop Genetics and Germplasm Enhancement/National Center for Soybean Improvement/Key Laboratory for Biology and Genetic Improvement of Soybean (General, Ministry of Agriculture)/Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China yanli1@njau.edu.cn sri@njau.edu.cn.
authors.forename: Junyi
authors.initials: J
authors.lastname: Gai
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D055864:Droughts; D035264:Flowers / Q000187:drug effects / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D018745:Genome, Plant; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism; D008353:Mannitol / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D009995:Osmosis / Q000187:drug effects; D010641:Phenotype; D017440:Photoperiod; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology; D030821:Plants, Genetically Modified; D011485:Protein Binding / Q000187:drug effects; D011523:Protoplasts / Q000187:drug effects / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013025:Glycine max / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D008353:Mannitol; D012965:Sodium Chloride; D000040:Abscisic Acid; D044767:Ubiquitin-Protein Ligases
keywords: Abiotic stress; Drought stress; Gene expression; Glycine max (L.) Merr; Protein–protein interaction; U-box E3 ubiquitin ligases