Changes in antioxidant systems in sunflower partial resistant and susceptible lines as affected by Sclerotinia sclerotiorum

Abstract

Sunflower, Helianthus annuus L., is a major oil-seed crop widely cultivated throughout the globe. White mold, caused by necrotrophic pathogen Sclerotinia sclerotiorum (Lib.) de Bary, is a common and widespread disease of sunflower. Changes in various physiological activities such as production of malondialdehyde (MDA) as the main end product of lipid peroxidation, enzymatic and non-enzymatic activities and proline content, were investigated in leaves and stems of sunflower lines either resistant or susceptible to S. sclerotiorum. The results showed accumulation of high amount of free proline in the leaves of the resistant line. S. sclerotiorum invasion resulted in increase in the MDA content in both lines compared to the controls. Superoxide dismutase, ascorbate peroxidase and guaiacol peroxidase activities significantly increased in the stem and leaves of inoculated lines. In the resistant line, Sclerotinia infection significantly induced catalase (CAT) activity both in the stem and leaves of contaminated plants. The activity of CAT was significantly decreased in susceptible line. Based on our results the activity of antioxidant enzymes was much pronounced in sunflower resistant line than in susceptible one. Studied lines showed distinctive activity considering different biochemical parameters, which may point to further directions in exploring host-pathogen interaction and lead to selection and production of new lines to achieve an improvement of plant adaptation to pathogen.

Effects of low-temperature hardening on the biochemical response of winter oilseed rape seedlings inoculated with the spores of Leptosphaeria maculans

“…glutathione, tocopherols, carotenoids, ascorbic acid, phenolics), or an increase in the activity of antioxidant enzymes [e.g. catalase (CAT), superoxide dismutase, peroxidase] (Mittler 2002;De Gara et al 2003;Davar et al 2013).…”

Induced resistance during the interaction pathogen x plant and the use of resistance inducers

“…It also acts as a second messenger, being responsible for the activation of the benzoic acid hydrolase, the enzyme responsible for the conversion of benzoic acid into salicylic acid. ROS are highly reactive and toxic to the cell and to the attacker, being quickly removed from the medium by antioxidant enzymes such as superoxide dismutases, ascorbate/glutathione cycle enzymes, catalase and b-carotene (Raoni and Jyothsna, 2010;Davar et al, 2013;Shah et al, 2014). SODs can be linked to a metal, Cu/Zn, Mn and Fe, present in the cytosol, chloroplasts and mitochondria, respectively.…”

“…Additionally, this pathway induces the production of H 2 O 2 , a reactive oxygen species (ROS) that can act as a first defence signalling molecule in plants. A number of other reactive species, as well as several antioxidant enzymes, are constantly modulated in the presence of a certain stress in order to overcome it (Vandenborre et al, 2011;O'Brien et al, 2012;Davar et al, 2013;Raoni and Pratyusha, 2013).…”

Enzymatic activities and pathogenesis-related genes expression in sunflower inbred lines affected bySclerotinia sclerotiorumculture filtrate

“…Our results were in accordance with the results of other researchers in terms of increasing the activity of SOD (Davar et al . ; Liu et al . ) and POX (Liu et al .…”