Regulation of defence response in Eruca sativa plants inoculated with Alternaria brassicicola

• Published in: Archiv für Phytopathologie und Pflanzenschutz Vol. 47; no. 12; pp. 1408 - 1414
• Main Authors: Gupta, Poonam, Ravi, Indu, Sharma, Vinay
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 21.07.2014; Taylor & Francis Ltd
• Subjects: Alternaria brassicicola; anti-infective agents; biotic stress; defence response; Eruca sativa; Eruca vesicaria subsp. sativa; flavonoids; flavonols; fungi; isoflavones; metabolism; oilseed crops; pathogens; phenolic acids; phenylalanine ammonia lyase; plant response; polyphenols; secondary metabolites; semiarid zones
• ISSN: 1477-2906; 0323-5408; 1477-2906
• DOI: 10.1080/03235408.2013.844469

Plants have developed a number of strategies to defend themselves against various pathogens or biotic stress. Secondary metabolites of plants are generally involved in defence against pathogens. Phenolics present in plants, as preformed antimicrobial compounds, inhibit the growth of fungi and may include phenolic acids, flavonols and some isoflavones. An almost ubiquitous feature of plant responses to pathogens is the activation of phenylpropanoid metabolism in which PAL catalyses the production of phenolic compounds. Polyphenol, flavonoid content and PAL activity were determined in two varieties viz. RTM-2002 (resistant) and T-27 (susceptible) control and pathogen (Alternaria brassicicola ; Schw., Wilt.) inoculated Eruca sativa Miller (rocket salad) plants. Polyphenol and flavonoid content were higher in pathogen-inoculated plants as compared to control plants with an increase till 168 h. A similar pattern of higher PAL activity was observed after pathogen inoculation with a maximum at 24 h in 10 days old plants of var. T-27 and at 48 h in var. RTM-2002. However, in 1–month-old plants, the maximum PAL activity was obtained at 24 h in both the varieties. The results indicate a role of polyphenol, flavonoids and PAL in the defence response of E. sativa , an economically important oilseed crop of semi-arid regions.