Title : Defense priming in rice: An innovative approach to enhance bacterial blight resistance in rice (Oryza sativa L.)
Abstract:
Many of the metabolites that plants produce offer defense against phytopathogens. The environment is harmed when synthetic bactericides are used excessively to control plant disease. Therefore, sustainable agriculture requires a promising and environmentally friendly method. Here, we show that rice becomes resistant to Xanthomonas oryzae pv. oryzae (Xoo) when foliar-sprayed with leaf extracts of Argemone mexicana, Eucalyptus globulus, Bassia scoparia, Mallotus philippensis, and Shorea robusta. From the 3rd to the 12th day of observation, the Xoo invasion was much lessened by extract treatment. Additionally, increased chlorophyll A fluorescence was noted which indicate the photosystem's defense against Xoo damage in treated leaves. Antioxidant enzymes like guaiacol peroxidase, catalase, superoxidase dismutase, glutathione reductase, and total protein content were measured on the 3rd, 6th , and 9th days following extract application in order to assess the resistance that had evolved. Particularly on the 6th and 9th days following treatment, treated leaves had higher amounts of antioxidant enzymes and protein than the control. Subsequently, Malondialdehyde, a marker of stress-induced damage, was noted to decrease in the leaves that received treatment by the 9th day. Furthermore, an increase in the concentration of phenols, tannins, and flavonoids in the plant extract confirmed the existence of phytochemicals that could potentially activate resistance mechanisms. Comparable outcomes were observed in their antioxidant properties. Finally, FT-IR analysis validated the presence of various functional groups, indicating unique metabolites within the plant samples. Therefore, the improved resistance to bacterial blight in rice leaves treated with plant extracts can be linked to the effects that trigger resistance.
