Groundnut is an important oilseed crop of the Indian subcontinent. Yield losses due to fungal diseases are enormous in the cultivation of this crop. Over-expression of PR proteins leads to increased resistance to pathogenic fungi in several crops. The PR protein glucanase hydrolyses a major cell-wall component, glucan, of pathogenic fungi and acts as a plant defense barrier. We report in this paper, overexpression of a tobacco glucanase in transgenic groundnut and its resistance towards Cercospora arachidicola and Aspergillus flavus. PCR, Southern and Northern hybridization confirmed stable integration and expression of the glucanase gene in groundnut transgenics. When screened for resistance against Cercospora arachidicola the transgenics showed not only reduction in the number of spots but also delay in the onset of disease. Resistance was also demonstrated against one another important pathogen of groundnut, Aspergillus flavus. The transgenics not only resisted hyphal spread but also did not accumulate aflatoxin in the seeds. The results demonstrate the potential of a PR protein from a heterologous source in developing fungal disease resistant groundnut.

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Coleus forskohlii Briq. is a threatened medicinal plant was transformed with glucanase-chitinase gene along with npt-II gene. The transformants were obtained on MSO supplemented with 2 mg/l or 3 mg/l BAP and 0.2 mg/l 2,4-D for callus induction using leaf as explants. Multiple shoot production from the leaf-derived transformed callus of Coleus has been standardized using the various concentration of NAA with 2 mg/l BAP. The combination of 2 mg/l BAP and 0.5 mg/l NAA was found to be best for multiple shoot production. Rooting of the transformed shoots was found to be best on MS medium supplemented with 0.7 mg/l NAA. The presence of npt-II genes in the leaves of putative transformants was confirmed by PCR analysis. SDS-PAGE analysis and glucanase assay revealed the over expression of glucanase enzyme in the transgenic plants. The transgenic Coleus plants survived the infection caused by Fusarium chlamydosporium due to the accumulation of glucanase-chitinase enzyme, whereas control plants were susceptible to the disease.