title: BnaC.Tic40, a plastid inner membrane translocon originating from Brassica oleracea, is essential for tapetal function and microspore development in Brassica napus.
abstract: Here, we describe the characteristics of a Brassica napus male sterile mutant 7365A with loss of the BnMs3 gene, which exhibits abnormal enlargement of the tapetal cells during meiosis. Later in development, the absence of the BnMs3 gene in the mutant results in a loss of the secretory function of the tapetum, as suggested by abortive callose dissolution and retarded tapetal degradation. The BnaC.Tic40 gene (equivalent to BnMs3) was isolated by a map-based cloning approach and was confirmed by genetic complementation. Sequence analyses suggested that BnaC.Tic40 originated from BolC.Tic40 on the Brassica oleracea linkage group C9, whereas its allele Bnms3 was derived from BraA.Tic40 on the Brassica rapa linkage group A10. The BnaC.Tic40 gene is highly expressed in the tapetum and encodes a putative plastid inner envelope membrane translocon, Tic40, which is localized into the chloroplast. Transmission electron microscopy (TEM) and lipid staining analyses suggested that BnaC.Tic40 is a key factor in controlling lipid accumulation in the tapetal plastids. These data indicate that BnaC.Tic40 participates in specific protein translocation across the inner envelope membrane in the tapetal plastid, which is required for tapetal development and function.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Dun
authors.forename: Zhengfu
authors.initials: Z
authors.lastname: Zhou
authors.forename: Shengqian
authors.initials: S
authors.lastname: Xia
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Shen
authors.forename: Chaozhi
authors.initials: C
authors.lastname: Ma
authors.forename: Jinxing
authors.initials: J
authors.lastname: Tu
authors.forename: Tingdong
authors.initials: T
authors.lastname: Fu
mesh_terms: D001937:Brassica / Q000235:genetics* / Q000378:metabolism; D029688:Brassica napus / Q000254:growth & development*; D060365:Chloroplast Proteins / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D050356:Lipid Metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051479:Plant Infertility; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011058:Pollen / Q000254:growth & development*; D021381:Protein Transport; D017422:Sequence Analysis, DNA
chemical_list: D060365:Chloroplast Proteins; D008565:Membrane Proteins; D010940:Plant Proteins