title: Molecular cloning, expression profiles, and characterization of a novel polyphenol oxidase (PPO) gene in Hevea brasiliensis.
abstract: The polyphenol oxidase (PPO) is involved in undesirable browning in many plant foods. Although the PPOs have been studied by several researchers, the isolation and expression profiles of PPO gene were not reported in rubber tree. In this study, a new PPO gene, HbPPO, was isolated from Hevea brasiliensis. The sequence alignment showed that HbPPO indicated high identities to plant PPOs and belonged to dicot branch. The cis-acting regulatory elements related to stress/hormone responses were predicted in the promoter region of HbPPO. Real-time RT-PCR analyses showed that HbPPO expression varied widely depending on different tissues and developmental stages of leaves. Besides being associated with tapping panel dryness, the HbPPO transcripts were regulated by ethrel, wounding, H2O2, and methyl jasmonate treatments. Moreover, the correlation between latex coagulation rate and PPO activity was further confirmed in this study. Our results lay the foundation for further analyzing the function of HbPPO in rubber tree.
authors: a Key Laboratory of Rubber Biology, Ministry of Agriculture , Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences , Danzhou , China.
authors: Dejun
authors: D
authors: Li
authors: Zhi
authors: Z
authors: Deng
authors: Changren
authors: C
authors: Liu
authors: Manman
authors: M
authors: Zhao
authors: Huina
authors: H
authors: Guo
authors: Zhihui
authors: Z
authors: Xia
authors: Hui
authors: H
authors: Liu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004156:Catechol Oxidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D019295:Computational Biology; D018506:Gene Expression Regulation, Plant; D028482:Hevea / Q000201:enzymology* / Q000235:genetics*; D007840:Latex / Q000737:chemistry; D008969:Molecular Sequence Data; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics
chemical_list: D007840:Latex; D004156:Catechol Oxidase
keywords: Hevea brasiliensis; expression profiles; latex coagulation; polyphenol oxidase; tapping panel dryness