Cloning and expression of pathogenesis-related protein 4 from jelly fig (Ficus awkeotsang Makino) achenes associated with ribonuclease, chitinase and anti-fungal activities

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• 作者：Hsi-Chi Lu^a ; Jia-Hui Lin^b ; Anna C.N. Chua^c ; Tse-Yu Chung^c ; I.-Chun Tsai^b ; Jason T.C. Tzen^c ; Wing-Ming Chou^b ; ^{wingming@sunws.nfu.edu.tw}
• 关键词：Pathogenesis-related protein 4 ; Ribonuclease ; Anti-fungal ; Pericarp ; Achene ; Ficus awkeotsang
• 刊名：Plant Physiology and Biochemistry
• 出版年：2012
• 期刊代码：87_09819428
• 类别：abs
• 出版时间：July, 2012
• 卷：56
• 期：Complete
• 页码：1-13
• 文件大小：1773 K

摘要

A cDNA fragment (FaPR4) encoding a class I pathogenesis-related protein 4 (PR-4) from Ficus awkeotsang was obtained by PCR cloning. Plant PR-4s were grouped into class I and II, differing by the presence of ChtBD and hinge. The predicted mature FaPR4 comprises N-terminal chitin-binding domain (ChtBD), hinge, Barwin domain and C-terminal extension. FaPR4-C, an N-terminal truncated form of FaPR4, was designed to mimic the structural feature of class II PR-4s. FaPR4 and FaPR4-C were over-expressed in yeast Pichia pastoris, and both recombinants exhibited RNase and anti-fungal activities. To our knowledge, it is the first report that FaPR4, a member of class I PR-4s has RNase activity as class II. FaPR4 possesses better anti-fungal activities toward Fusarium oxysporum and Sclerotium rolfsii than FaPR4-C. Heat-treated FaPR4 remained RNase and anti-fungal activities; while heat-treated FaPR4-C lost those activities. Therefore, ChtBD of FaPR4 may not only contribute to its anti-fungal but also improve the thermal stability of protein. It also implied the correlation of RNase activity with anti-fungal activity of FaPR4-C. Furthermore, FaPR4 was detected to have weak but significant chitinase activity, and its chitinase activity was reduced after heat treatment. The chitinase activity by FaPR4-C was much lower than FaPR4.