Authors:R. Radhajeyalakshmi, K. Yamunarani, K. Seetharaman and R. Velazhahan
Seed extracts of pearl millet, sorghum, Japanese barnyard millet, foxtail millet, samai and proso millet were evaluated in vitro for their ability to inhibit the growth of Rhizoctonia solani, Macrophomina phaseolina and Fusarium oxysporum. Among them, seed extracts of pearl millet and sorghum were highly effective in inhibiting the growth of all three examined phytopathogenic fungi. The seed extracts were tested for the presence of thaumatin-like proteins (TLPs) by Western blot analysis using bean TLP antiserum. Results of Western blot analysis indicated the presence of a 23-kDa TLP in seeds of pearl millet, sorghum and Japanese barnyard millet. The 23-kDa TLP was more abundant in the seeds of pearl millet. The distribution of TLP in various parts of pearl millet was analyzed by Western blotting. The results indicated that the 23 kDa TLP was predominantly expressed in seeds and inflorescence of pearl millet.
Authors:R. M. Babu, R. Velazhahan, P. Vidhyasekaran, K. Seetharaman and A. Sajeena
Systemic acquired resistance induced by benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH) in rice against bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae was studied. Rice plants (IR 50) pre-treated with BTH showed resistance to a challenge infection with Xanthomonas oryzae pv. oryzae. About 50% reduction in disease intensity was observed in plants treated with BTH at 100 µg a.i./ml. Immunoblot analysis using barley chitinase antiserum revealed the induction of a 35 kDa chitinase in rice in response to treatment with BTH. The results indicate that the BLB resistance can be induced even in genetically susceptible cultivar through application of BTH.