title: GDSL esterase/lipase genes in Brassica rapa L.: genome-wide identification and expression analysis.
abstract: GDSL esterase/lipase proteins (GELPs), a very large subfamily of lipolytic enzymes, have been identified in microbes and many plants, but only a few have been characterized with respect to their roles in growth, development, and stress responses. In Brassica crops, as in many other species, genome-wide systematic analysis and functional studies of these genes are still lacking. As a first step to study their function in B. rapa ssp. pekinensis (Chinese cabbage), we comprehensively identified all GELP genes in the genome. We found a total of 121 Brassica rapa GDSL esterase/lipase protein genes (BrGELPs), forming three clades in the phylogenetic analysis (two major and one minor), with an asymmetrical chromosomal distribution. Most BrGELPs possess four strictly conserved residues (Ser-Gly-Asn-His) in four separate conserved regions, along with short conserved and clade-specific blocks, suggesting functional diversification of these proteins. Detailed expression profiling revealed that BrGELPs were expressed in various tissues, including floral organs, implying that BrGELPs play diverse roles in various tissues and during development. Ten percent of BrGELPs were specifically expressed in fertile buds, rather than male-sterile buds, implying their involvement in pollen development. Analyses of EXL6 (extracellular lipase 6) expression and its co-expressed genes in both B. rapa and Arabidopsis, as well as knockdown of this gene in Arabidopsis, revealed that this gene plays an important role in pollen development in both species. The data described in this study will facilitate future investigations of other BrGELP functions.
authors.affiliation: Department of Biological Sciences, College of Biological Science and Biotechnology, Chungnam National University, Taejon, Republic of Korea.|School of Agriculture, Yunnan University, Kunming, Yunnan, China.
authors.forename: Xiangshu
authors.initials: X
authors.lastname: Dong
authors.affiliation: Department of Biological Sciences, College of Biological Science and Biotechnology, Chungnam National University, Taejon, Republic of Korea.
authors.forename: Hankuil
authors.initials: H
authors.lastname: Yi
authors.affiliation: Department of Life Science, Sogang University, Seoul, 100-611, Republic of Korea.
authors.forename: Ching-Tack
authors.initials: CT
authors.lastname: Han
authors.affiliation: Department of Horticulture, Sunchon National University, Suncheon, Jeonnam, Republic of Korea.
authors.forename: Ill-Sup
authors.initials: IS
authors.lastname: Nou
authors.affiliation: Department of Biological Sciences, College of Biological Science and Biotechnology, Chungnam National University, Taejon, Republic of Korea. ykhur@cnu.ac.kr.
authors.forename: Yoonkang
authors.initials: Y
authors.lastname: Hur
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029741:Brassica rapa / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D004950:Esterases / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D008049:Lipase / Q000235:genetics*; D010802:Phylogeny; D063245:Plant Development / Q000235:genetics; D011058:Pollen / Q000235:genetics / Q000254:growth & development*
chemical_list: D004950:Esterases; D008049:Lipase
keywords: BrGELP subfamily; Brassica rapa; Extracellular lipase 6; Pollen development; SGNH hydrolase