Extracellular Chitinases of Fluorescent Pseudomonads Antifungal to Fusarium oxysporum f. sp. dianthi Causing Carnation Wilt
IR@IHBT: CSIR-Institute of Himalayan Bioresource Technology, Palampur
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| Title |
Extracellular Chitinases of Fluorescent Pseudomonads Antifungal to
Fusarium oxysporum f. sp. dianthi Causing Carnation Wilt
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| Creator |
NS, Ajit
Verma, Rajni Shanmugam, V |
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| Subject |
Microbiology
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| Description |
Vascular wilt of carnation caused by Fusarium oxysporum f. sp. dianthi (Prill. & Delacr.)
W. C. Synder & H.N. Hans inflicts substantial yield and quality loss to the crop. Mycolytic enzymes
such as chitinases are antifungal and contribute significantly to the antagonistic activity of fluorescent
pseudomonads belonging to plant-growth-promoting rhizobacteria. Fluorescent pseudomonads antagonistic
to the vascular wilt pathogen were studied for their ability to grow and produce chitinases on
different substrates. Bacterial cells grown on chitin-containing media showed enhanced growth and
enzyme production with increased anti-fungal activity against the pathogen. Furthermore, the cell-free
bacterial culture filtrate from chitin-containing media also significantly inhibited the mycelial growth.
Both the strains and their cell-free culture filtrate from chitin-amended media showed the formation of
lytic zones on chitin agar, indicating chitinolytic ability. Extracellular proteins of highly antagonistic
bacterial strain were isolated from cell-free extracts of media amended with chitin and fungal cell wall.
These cell-free conditioned media contained one to seven polypeptides. Western blot analysis revealed
two isoforms of chitinase with molecular masses of 43 and 18.5 kDa. Further plate assay for mycelial
growth inhibition showed the 43-kDa protein to be antifungal. The foregoing studies clearly established
the significance of chitinases in the antagonism of fluorescent pseudomonads, showing avenues for
possible exploitation in carnation wilt management.
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| Date |
2006
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://ihbt.csircentral.net/203/1/Extra.pdf
NS, Ajit and Verma, Rajni and Shanmugam, V (2006) Extracellular Chitinases of Fluorescent Pseudomonads Antifungal to Fusarium oxysporum f. sp. dianthi Causing Carnation Wilt. Current Mircobiology, 52 (4). pp. 310-316. |
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| Relation |
http://ihbt.csircentral.net/203/
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