Journal of Applied Microbiology (2014) 116, 654-666

B.N. Singh, A. Singh, B.R. Singh and H.B. Singh (2014)
Trichoderma harzianum elicits induced resistance in sunflower challenged by Rhizoctonia solani
Journal of Applied Microbiology 116 (3), 654-666
Abstract:
Aims
To investigate the efficacy of Trichoderma harzianum NBRI-1055 (denoted as 'T-1055') in suppression of seedling blight of sunflower caused by Rhizoctonia solani Kühn and their impact on host defence responses.
Methods and Results
T-1055 was applied as seed treatment, soil application and combined application (seed treatment + soil application). Higher protection afforded by combined application of T-1055 was associated with the marked induction of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (PO) and cinnamyl alcohol dehydrogenase (CAD) activities. The activities of PAL and PPO reached maximum at 10 days after sowing (DAS), while PO and CAD levels reached maximum at 12 DAS. This was further supported by the accumulation of total phenolic content that showed an increase up to threefold at 14 DAS. In addition, HPLC analysis revealed that the contents of ferulic and p-coumaric acids increased by 6·3 and 4·6 times, respectively, at 14 DAS. Amount of gallic acid was also little more than double. Lignin deposition in sunflower root increased by 2·7, 3·4 and 3·7 times through combined application of T-1055 at 16, 18 and 20 DAS, respectively. Combined application also increased the accumulation of PR-2 and PR-3 proteins by 3·3 and 3·9 times, respectively, at 12 DAS in followed by seed treatment alone.
Conclusions
The combined application of T-1055 triggered defence responses in an enhanced level in sunflower than the soil and seed alone and provided better protection against Rhizoctonia seedling blight.
Significance and Impact of the Study
Rhizospheric fungal bioagent 'T-1055' can enhance protection in sunflower against the R. solani pathogen through augmented elicitation of host defence responses.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Harikesh B. Singh

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhizoctonia solani	Sunflower (Helianthus annuus)
Trichoderma harzianum (antagonist)	Rhizoctonia solani	Sunflower (Helianthus annuus)