title: Genome-wide identification, classification, and expression analysis of autophagy-associated gene homologues in rice (Oryza sativa L.).
abstract: Autophagy is an intracellular degradation process for recycling macromolecules and organelles. It plays important roles in plant development and in response to nutritional demand, stress, and senescence. Organisms from yeast to plants contain many autophagy-associated genes (ATG). In this study, we found that a total of 33 ATG homologues exist in the rice [Oryza sativa L. (Os)] genome, which were classified into 13 ATG subfamilies. Six of them are alternatively spliced genes. Evolutional analysis showed that expansion of 10 OsATG homologues occurred via segmental duplication events and that the occurrence of these OsATG homologues within each subfamily was asynchronous. The Ka/Ks ratios suggested purifying selection for four duplicated OsATG homologues and positive selection for two. Calculating the dates of the duplication events indicated that all duplication events might have occurred after the origin of the grasses, from 21.43 to 66.77 million years ago. Semi-quantitative RT-PCR analysis and mining the digital expression database of rice showed that all 33 OsATG homologues could be detected in at least one cell type of the various tissues under normal or stress growth conditions, but their expression was tightly regulated. The 10 duplicated genes showed expression divergence. The expression of most OsATG homologues was regulated by at least one treatment, including hormones, abiotic and biotic stresses, and nutrient limitation. The identification of OsATG homologues showing constitutive expression or responses to environmental stimuli provides new insights for in-depth characterization of selected genes of importance in rice.
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China.
authors.forename: Kuaifei
authors.initials: K
authors.lastname: Xia
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Ouyang
authors.forename: Ren
authors.initials: R
authors.lastname: Wang
authors.forename: Tian
authors.initials: T
authors.lastname: Fan
authors.forename: Mingyong
authors.initials: M
authors.lastname: Zhang
mesh_terms: D001343:Autophagy / Q000235:genetics* / Q000502:physiology; D019295:Computational Biology / Q000379:methods; D020440:Gene Duplication; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics*; D018869:Heat-Shock Response; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D048348:Reverse Transcription; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D010940:Plant Proteins