title: Functional analyses of chitinases in the moss Physcomitrella patens: chitin oligosaccharide-induced gene expression and enzymatic characterization.
abstract: Plant chitinases play diverse roles including defense against pathogenic fungi. Using reverse-transcription quantitative PCR analysis, we found that six chitinase (PpChi) genes and two genes for chitin elicitor receptor kinases (PpCERKs) are expressed at considerable levels in the moss Physcomitrella patens subsp. patens. The expressed PpChis belonged to glycoside hydrolase family 19 (class I: PpChi-Ia and -Ib; class II: PpChi-IIa and -IIc; and class IV: PpChi-IV) and to glycoside hydrolase family 18 (class V: PpChi-Vb). Treatment with chitin tetramer or hexamer increased the expression of class I and IV PpChi genes and decreased that of class II PpChi genes. Recombinant PpChi-Ia, PpChi-IV, and PpChi-Vb were characterized. PpChi-IV exhibited higher activity against chitin tetramer and pentamer than PpChi-Ia did. PpChi-Vb showed transglycosylation activity and PpChi-Ia inhibited fungal growth. These results suggest that chitinases of different classes play different roles in defense mechanism of moss plant against fungal pathogens.
authors: a Graduate School of Science and Engineering , Kagoshima University , Kagoshima , Japan.
authors: Saki
authors: S
authors: Kobaru
authors: b Department of Bioscience and Biotechnology , University of the Ryukyus , Nishihara-cho , Japan.
authors: Ryusuke
authors: R
authors: Tanaka
authors: b Department of Bioscience and Biotechnology , University of the Ryukyus , Nishihara-cho , Japan.
authors: Toki
authors: T
authors: Taira
authors: a Graduate School of Science and Engineering , Kagoshima University , Kagoshima , Japan.
authors: Toshiki
authors: T
authors: Uchiumi
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology; D019068:Bryopsida / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D002686:Chitin / Q000737:chemistry*; D002688:Chitinases / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D009844:Oligosaccharides / Q000737:chemistry* / Q000494:pharmacology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014242:Trichoderma / Q000187:drug effects
chemical_list: D000935:Antifungal Agents; D009844:Oligosaccharides; D002686:Chitin; D002688:Chitinases
keywords: chitin oligosaccharide elicitor; chitinase; enzymatic activity; gene expression; moss