Plant Pathology (2013) 62, 552-561

A. Kamble, B. Koopmann and A. von Tiedemann (2013)
Induced resistance to Verticillium longisporum in Brassica napus by β-aminobutyric acid
Plant Pathology 62 (3), 552-561
Abstract: A preinoculative soil drench application of 0·5 mm β-aminobutyric acid (BABA) significantly inhibited colonization of oilseed rape (Brassica napus, susceptible cultivar Falcon) by Verticillium longisporum and also prevented plant stunting caused by the pathogen. To better understand the defence responses induced by BABA, the presence of occlusions in the plant hypocotyl, levels of salicylic acid (SA) and hydrogen peroxide (H₂O₂), phenylalanine ammonia lyase (PAL) activity and expression of PR-1 and PDF1.2 genes were examined. Transverse sections through the hypocotyl region of BABA-treated plants showed clear vessels surrounded by phenol-storing cells, in contrast to numerous obstructed vessels in water-treated plants, in response to the pathogen. A significant increase in SA levels was observed in the hypocotyls of both water- and BABA-treated plants in response to the pathogen; however, SA levels were unrelated to disease resistance. The level of H₂O₂ decreased in both treatments in response to the pathogen. A significant increase in PAL activity was observed in hypocotyl tissues of BABA-treated plants. The expression patterns of PR-1 and PDF1.2 were similar in the two treatments in response to the pathogen, indicating no involvement of these genes in resistance. The results indicate a similar organ specificity of the plant hypocotyl for chemically induced internal resistance as for genotype-related resistance, two phenomena which, however, are based on contrasting cytological responses in the vascular tissues. Nonetheless, evidence is provided that the activity of the phenylpropanoid pathway plays a crucial role in both types of resistance.
(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): Avinash Kamble, Andreas von Tiedemann

Research topic(s) for pests/diseases/weeds:
control - general
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Verticillium longisporum	Rape/canola (Brassica napus)