title: Importance of the rice TCD9 encoding α subunit of chaperonin protein 60 (Cpn60α) for the chloroplast development during the early leaf stage.
abstract: The chloroplast development governs plant growth and metabolism. This study characterized a novel rice thermo-sensitive chloroplast development 9 (tcd9) mutant, which exhibited the albino phenotype before the 3-leaf stage grown below 24 °C whereas displayed normal green at over 28 °C or even at 20 °C after 5-leaf stage. The obvious decrease in Chl levels, abnormal chloroplasts with few thylakoid lamella and abnormal thylakoids were observed for the albino mutant seedlings at low temperature, but the mutant was apparently normal green at high temperature, suggesting the thermo-sensitivity of albino phenotype. Genetic analysis showed that the albino phenotype was controlled by a single recessive nuclear gene (tcd9). The map-based cloning and molecular complementation tests revealed that the mutation of TCD9 encoding α subunit of Cpn60 protein (Cpn60α), localized in chloroplasts, was responsible for albino phenotype. In addition, TCD9 exhibited the high expression in all tested tissues, especially in young leaves. The transcriptional analysis indicated that all expression levels of the studied genes related to chloroplast development in tcd9 mutant were seriously affected in the albino seedlings at 20 °C, whereas some of them recovered into normal levels in green-seedlings at 32 °C. Our observations suggest that the nuclear-encoded Cpn60α protein TCD9 plays a crucial role in chloroplast development at early leaf stage of rice.
authors.affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Mei
authors.affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China.
authors.forename: Xiao-Di
authors.initials: XD
authors.lastname: Gong
authors.affiliation: The Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan Cun Street, Beijing 100081, China.
authors.forename: Jian-Long
authors.initials: JL
authors.lastname: Xu
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Zhang
authors.affiliation: Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Teng
authors.affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China. Electronic address: dzlin@shun.edu.cn.
authors.forename: Dong-Zhi
authors.initials: DZ
authors.lastname: Lin
authors.affiliation: Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China. Electronic address: dong@shnu.edu.cn.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Dong
mesh_terms: D018834:Chaperonin 60 / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000235:genetics* / Q000378:metabolism; D061125:Genes, Chloroplast; D017343:Genes, Plant; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010641:Phenotype; D063245:Plant Development / Q000235:genetics*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D021122:Protein Subunits / Q000235:genetics* / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013696:Temperature
chemical_list: D018834:Chaperonin 60; D010940:Plant Proteins; D021122:Protein Subunits
keywords: Chloroplast development; Cpn60α protein; Map-based cloning; Rice (Oryza sativa L.); Subcellular localization; Thermo-sensitive