title: Heterodimer Formation of BnPKSA or BnPKSB with BnACOS5 Constitutes a Multienzyme Complex in Tapetal Cells and is Involved in Male Reproductive Development in Brassica napus.
abstract: Multienzyme associations localized to specific subcellular sites are involved in several critical functions in cellular metabolism, such as plant survival and reproduction. To date, few multienzyme complexes involved in male fertility have been examined in Brassica napus Here, we reported that in B. napus, the members of a multienzyme complex work in an interaction pattern different from that in Arabidopsis thaliana for sporopollenin biosynthesis. 7365A, a male-sterile mutant with a relatively smooth anther cuticle, was found to have a dramatic reduction in both cutin monomers and wax composition. Proteomic comparison between the mutant 7365A and wild-type 7365B showed down-regulation of three sporopollenin biosynthetic enzymes, namely BnPKSA, BnPKSB and BnTKPR; these enzymes were tightly co-expressed with BnACOS5. BnPKSA and BnPKSB showed similar expression patterns but distinct accumulation levels, suggesting that they had partially distinct functions during sporopollenin biosynthesis. In vitro and in vivo analyses demonstrated that BnPKSB directly interacted with BnPKSA and BnACOS5, but no such interactions were found in the present investigation for BnTKPR1. Interestingly, the interaction between PKSA and PKSB has not been discovered in Arabidopsis, which may indicate a new interaction representing an additional efficient regulation method in B. napus Taken together, we propose that BnPKSA and BnPKSB may comprise a heterodimer combined with BnACOS5, constituting a sporopollenin metabolon in tapetal cells that is related to male reproductive development in B. napus.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Maomao
authors.initials: M
authors.lastname: Qin
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Tiantian
authors.initials: T
authors.lastname: Tian
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Shengqian
authors.initials: S
authors.lastname: Xia
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Song
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Shen
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Chaozhi
authors.initials: C
authors.lastname: Ma
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Tingdong
authors.initials: T
authors.lastname: Fu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement, Huazhong Agricultural University, Wuhan 430070, China tujx@mail.hzau.edu.cn.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Tu
mesh_terms: D001704:Biopolymers / Q000096:biosynthesis / Q000235:genetics; D029688:Brassica napus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D002338:Carotenoids / Q000096:biosynthesis / Q000235:genetics; D015536:Down-Regulation; D035264:Flowers / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D018506:Gene Expression Regulation, Plant; D008563:Membrane Lipids / Q000378:metabolism; D008954:Models, Biological; D009097:Multienzyme Complexes; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D040901:Proteomics
chemical_list: D001704:Biopolymers; D008563:Membrane Lipids; D009097:Multienzyme Complexes; D010940:Plant Proteins; C009800:sporopollenin; D002338:Carotenoids; C000521:cutin
keywords: Anther cuticle; BnMs3; Brassica napus; Lipid metabolism; Male reproductive development; Sporopollenin metabolon