Chitinolytic and antifungal activity of a Bacillus pumilus chitinase expressed in Arabidopsis.
The Bacillus pumilus SG2 chitinase gene (ChiS) and its truncated form lacking chitin binding (ChBD) and fibronectin type III (FnIII) domains were transformed to Arabidopsis plants and the expression, functionality and antifungal activity of the recombinant proteins were investigated. Results showed that while the two enzyme forms showed almost equal hydrolytic activity toward colloidal chitin, they exhibited a significant difference in antifungal activity. Recombinant ChiS in plant protein extracts displayed a high inhibitory effect on spore germination and radial growth of hyphae in Alternaria brassicicola, Fusarium graminearum and Botrytis cinerea, while the activity of the truncated enzyme was strongly abolished. These findings demonstrate that ChBD and FnIII domains are not necessary for hydrolysis of colloidal chitin but play an important role in hydrolysis of chitin-glucan complex of fungal cell walls. Twenty microgram aliquots of protein extracts from ChiS transgenic lines displayed strong antifungal activity causing up to 80% decrease in fungal spore germination. This is the first report of a Bacillus pumilus chitinase expressed in plant system.
Dehestani
Ali
A
Department of Plant Breeding, Faculty of Agronomic Sciences, Sari Agricultural Sciences and Natural Resources University, P. O. Box 578, Sari, Iran.
Kazemitabar
Kamal
K
Ahmadian
Gholamreza
G
Jelodar
Nadali Babaeian
NB
Salmanian
Ali Hatef
AH
Seyedi
Mehdi
M
Rahimian
Heshmat
H
Ghasemi
Seyedhadi
S
D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D002688:Chitinases / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D009391:Nephelometry and Turbidimetry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013172:Spores, Fungal / Q000187:drug effects
D000935:Antifungal Agents; D011994:Recombinant Proteins; D002688:Chitinases