Isolation of Andrographis paniculata Leaf Protein with Antifungal Property MODHUMITA GHOSH *1 , D. THANGAMANI 1 , MANISHA THAPLIYAL 2 , R. YASODHA 1 and K. GURUMURTHI 3 1 Division of Plant Biotechnology, Institute of Forest Genetics and Tree Breeding, Forest Campus, R. S. Puram, Coimbatore- 641 002 India 2 Forest Tree Seed Laboratory, Silviculture Division, Forest Research Institute, Dehradun, India 3 Institute of Forest Genetics and Tree Breeding, Forest Campus, R. S. Puram, Coimbatore- 641 002 India The crude protein extract from the leaves of Andrographis paniculata was found to inhibit the spore germination of two major pathogens Aspergillus flavus and Macrophomina phaseolina. The antifungal protein component was further purified from the crude extract and the molecular mass of toxic protein was estimated to be 39.5 KDa. Keywords: plant defense mechanism, PR proteins, spore inhibition, systemic acquired resistance. Plants have several inducible defense mechanisms that act to limit pathogen infec- tion, like increased lignification, phytoalexin production and hypersensitive reaction (Hammond-Kosack and Jones, 1996). In addition, various novel proteins are induced which are collectively referred to as “pathogenesis-related” (PR) proteins. These proteins accumulate locally in the infected region, but are also induced systemically, associated with the development of systemic acquired resistance (SAR) against further infection. Induction of PRs has been found in many plant species belonging to various families (Van Loon, 1999) suggesting their role in adaptation to biotic stress condition. Some of the reports on purification of PR proteins are from tobacco (Van Loon, 1982), tomato (Vera and Conejero, 1988), barley (García-Olmedo et al., 1995; Christensen et al., 2002), Arabi- dopsis (Epple et al., 1995), maize (Malehorn et al., 1994), sunflower (Jung et al., 1993) and radish (Terras et al., 1992). In an attempt to identify a new source of antifungal protein, Andrographis paniculata was studied and the activity of the antifungal protein component purified was tested against two potent pathogens, Macrophomina phaseolina and Aspergillus flavus. These are two major pathogens in the tropical countries with a broad host range, the former infecting about 500 plant species and the latter a common colonizer and better known for the pro- duction of a mycotoxin called aflatoxin (Sinclair, 1982; Malaguti, 1990; IARC, 1993). Acta Phytopathologica et Entomologica Hungarica 39 (4), pp. 377–381 (2004) 0238–1249/$ 20.00 © 2004 Akadémiai Kiadó, Budapest * Corresponding author: E-mail: ghosm@ifgtb.res.in; fax: 91-0422-2430549