title: Identification and functional characterization of three type III polyketide synthases from Aquilaria sinensis calli.
abstract: Type III polyketide synthases (PKSs) play an important role in biosynthesis of various plant secondary metabolites and plant adaptation to environmental stresses. Aquilaria sinensis (A. sinensis) is the main plant species for production of agarwood, little is known about its PKS family. In this study, AsCHS1 and two new type III PKSs, AsPKS1 and AsPKS2, were isolated and characterized in A. sinensis calli. The comparative sequence and phylogenetic analysis indicated that AsPKS1 and AsPKS2 belonged to non-CHS group different from AsCHS1. The recombinant AsPKS1 and AsPKS2 produced the lactone-type products, suggesting their different enzyme activities from AsCHS1. Three PKS genes had a tissues-specific pattern in A. sinensis. Moreover, we examined the expression profiles of three PKS genes in calli under different abiotic stresses and hormone treatments. AsCHS1 transcript was most significantly induced by salt stress, AsPKS1 abundance was most remarkably enhanced by CdCl2treatment, while AsPKS2 expression was most significantly induced by mannitol treatment. Furthermore, AsCHS1, AsPKS1 and AsPKS2 expression was enhanced upon gibberellins (GA3), methyl jasmonate (MeJA), or salicylic acid (SA) treatment, while three PKS genes displayed low transcript levels at the early stage under abscisic acid (ABA) treatment. In addition, three GFP:PKSs fusion proteins were localized in the cytoplasm and cell wall in Nicotiana benthamiana cells. These results indicated the multifunctional role of three type III PKSs in polyketide biosynthesis, plant resistance to abiotic stresses and signal transduction.
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, People's Republic of China.
authors.forename: Zhongxiu
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
authors.forename: Xianjuan
authors.initials: X
authors.lastname: Dong
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Baotou Medical College, Baotou 014060, People's Republic of China.
authors.forename: Bowen
authors.initials: B
authors.lastname: Gao
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
authors.forename: Jinling
authors.initials: J
authors.lastname: Wang
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
authors.forename: Le
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China. Electronic address: shishepo@163.com.
authors.forename: Shepo
authors.initials: S
authors.lastname: Shi
authors.affiliation: Modern Research Center for Traditional Chinese Medicine, School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China. Electronic address: pengfeitu@163.com.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Tu
mesh_terms: D000217:Acyltransferases / Q000737:chemistry* / Q000502:physiology*; D002384:Catalysis; D007783:Lactones / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology*; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000378:metabolism*; D029645:Thymelaeaceae / Q000145:classification / Q000166:cytology / Q000201:enzymology*; D014018:Tissue Distribution
chemical_list: D007783:Lactones; D010940:Plant Proteins; D000217:Acyltransferases; C020141:flavanone synthetase
keywords: Aquilaria sinensis; Environmental stresses; Expression analysis; Hormone treatments; Lactone-type products; Type III polyketide synthase