Partial Purification of Lectin from Mycoparasitic Species of Trichoderma

Singh, Tanuja,Saikia, Ratul,Arora, Dilip K. The Korean Society of Plant Pathology 2005 Plant Pathology Journal Vol.21 No.4

Trichoderma species/isolates exhibited varied degree of agglutination on sclerotial (Sc) and hyphal (Hy) surface of Macrophomina phaseolina. The agglutination efficiencies on Sc and Hy ranged from $11\;to\;57\%$. Isolates of T. harzianum (Th) and T. viride (Tv) showed greater agglutination on Sc ($23-57\%$) and Hy ($16-47\%$). Different enzymes (trypsin, pepsin, proteinase k, a-chymotrypsin, lyticase and glucosidase) and inhibitors (tunicamycin, cycloheximide, brefeldin A, sodium azide, dithiothreitol and SDS) reduced the agglutination potential of conidia of Th-23/98 and Tv-25/98; however, the extent of response varied greatly in different treatments. Different fractions of Th-23/98 and Tv-25/98 exhibited haemagglutinating reaction with human blood group A, B, AB and O. Haemagglutinating activity was inhibited by different sugars and glycoproteins tested. Crude haemagglutinating protein from outer cell wall protein fraction of Th-23/98 and Tv-25/98 were eluted on Sephadex G-100 column. Initially Th-23/98 and Tv-25/98 exhibited two peaks showing no agglutination activity; however, lectin activity was detected in the third peak. Similar to crude lectin, the purified lectin also exhibited haemagglutinating activity with different erythrocyte source. SDS-PAGE analysis of partially purified lectin revealed single band with an estimated molecular mass of 55 and 52 kDa in Th-23/98 and Tv-25/98, respectively. Trypsin, chymotrypsin and b-1,3-glucanase totally inhibited lectin activity. Similarly, various pH also affected the haemagglutinating activity of Th-23/98 and Tv-25/98. From the present observations, it can be concluded that the recognition/attachment of mycoparasite (T. harzianum and T. viride) to the host surface (M. phaseolina) may be most likely due to lectin-carbohydrate interaction.

종류가 다른 무생물적 요인이 진균류에 미치는 세균의 주화성

이민웅,Gupta, Sushma,Arora, Dilip K.,Pandey, Arun K. 한국균학회 1992 韓國菌學會誌 Vol.20 No.2

Chemotactic responses of five motile saprophytic and one phytopathogenic bacteria e.g. Agrobacterium radiobacter, Bacillus subtilis, B. potymyxa, Pseudomonas aeruginosa, P. fluorescens and Xanthomonas malvacearum towards exudate of Cochliobolus sativus conidia, Fusarium oxysporum f. sp. ciceri chlamydospores, Macrophomina phaseolina sclerotia and Phytophthora drechsleri f. sp. cajani oospores were determined in vitro at different abiotic conditions. In general, a positive correlation (r=0.76 to 0.89; P=0.05) was observed between concentration of fungal exudates and attraction of bacterial cells. Similarly, a significant (P=0.05; r=+0.82 to 0.95) positive correlation was noticed between chemotactic response and incubation period. The chemotactic response of bacteria was greatly influenced by temperature and pH of the test fungal exudate. The optimum temperature for maximum chemotaxis was 25℃ for A. radiobacter, 30℃ for B. polymyxa, P. aerugionosa, P. fluorescens and X. malvacearum and 35℃ for B. subtilis. Fungal exudates maintained at pH 7 attracted maximum number of bacteria. The response of bacterial cells to exudates at pH 3 and 11 was not significantly (P=0.05) different than that to the buffer (control). Chemotaxis of bacteria was observed towards attractants (fungal propagates and their exudates) when they were kept apart and bridged with the capillaries filled with non-attractant (buffer) or attractant (exudate).

Partial Purification of Lectin from Mycoparasitic Species of Trichoderma

Tanuja Singh,Ratul Saikia,Dilip K. Arora 한국식물병리학회 2005 Plant Pathology Journal Vol.21 No.4

Trichoderma species/isolates exhibited varied degree of agglutination on sclerotial (Sc) and hyphal (Hy) surface of Macrophomina phaseolina. The agglutination efficiencies on Sc and Hy ranged from 11 to 57%. Isolates of T. harzianum (Th) and T. viride (Tv) showed greater agglutination on Sc (23-57%) and Hy (16-47%). Different enzymes (trypsin, pepsin, proteinase k, α-chymotrypsin, lyticase and glucosidase) and inhibitors (tunicamycin,cycloheximide, brefeldin A, sodium azide,dithiothreitol and SDS) reduced the agglutination potential of conidia of Th-23/98 and Tv-25/98; however, the extent of response varied greatly in different treatments.Different fractions of Th-23/98 and Tv-25/98 exhibited haemagglutinating reaction with human blood group A, B, AB and O. Haemagglutinating activity was inhibited by different sugars and glycoproteins tested. Crude haemagglutinating protein from outer cell wall protein fraction of Th-23/98 and Tv-25/98 were eluted on Sephadex G-100 column. Initially Th-23/98 and Tv- 25/98 exhibited two peaks showing no agglutination activity; however, lectin activity was detected in the third peak. Similar to crude lectin, the purified lectin also exhibited haemagglutinating activity with different erythrocyte source. SDS-PAGE analysis of partially purified lectin revealed single band with an estimated molecular mass of 55 and 52 kDa in Th-23/98 and Tv- 25/98, respectively. Trypsin, chymotrypsin and b-1,3- glucanase totally inhibited lectin activity. Similarly,various pH also affected the haemagglutinating activity of Th-23/98 and Tv-25/98. From the present observations, it can be concluded that the recognition/attachment of mycoparasite (T. harzianum and T. viride) to the host surface (M. phaseolina) may be most likely due to lectincarbohydrate interaction.

Research Articles : Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

( Ratul Saikia ),( Alok K. Srivastava ),( Kiran Singh ),( Dilip K. Arora ),( Min Woong Lee ) 한국균학회 2005 Mycobiology Vol.33 No.1

Research Articles : Induction of Defense Related Enzymes and Pathogenesis Related Proteins in Pseudomonas fluorescens-Treated Chickpea in Response to Infection by Fusarium oxysporum f. sp. Ciceri

( Ratul Saikia ),( Rakesh Kumar ),( Tanuja Singh ),( Alok K. Srivastava ),( Dilip K. Arora ),( Min Woong Lee ) 한국균학회 2004 Mycobiology Vol.32 No.1

Role of Riboflavin in Induced Resistance against Fusarium Wilt and Charcoal Rot Diseases of Chickpea

Ratul Saikia,yadav mukesh kumar,Saju Varghese,Bhim Pratap Singh,Dip K Gogoi,Rakesh Kumar,Dilip K Arora 한국식물병리학회 2006 Plant Pathology Journal Vol.22 No.4

Riboflavin caused induction of systemic resistance inchickpea against Fusarium wilt and charcoal rotdiseases. The dose effect of 0.01 to 20 mM riboflavinshowed that 1.0 mM concentration was sufficient formaximum induction of resistance; higher concentrationdid not increase the effect. At this concentration,riboflavin neither caused cell death of the host plant nordirectly affected the pathogen’s growth. In time courseobservation, it was observed that riboflavin treatedchickpea plants were inducing resistance 2 days aftertreatment and reached its maximum level from 5 to 7days and then decreased. Riboflavin had no effect onsalicylic acid (SA) levels in chickpea, however, riboflavininduced plants found accumulation of phenolsand a greater activities of phenylalanine ammonia lyase(PAL) and pathogenesis related (PR) protein, peroxidasewas observed in induced plant than the control. Riboflavin pre-treated plants challenged with thepathogens exhibited maximum activity of the peroxidases4 days after treatment. Molecular weight of thepurified peroxidase was 42 kDa. From these studies wedemonstrated that riboflavin induced resistance is PRproteinmediated but is independent of salicylic acid.

Role of Riboflavin in Induced Resistance against Fusarium Wilt and Charcoal Rot Diseases of Chickpea

Saikia Ratul,Yadav Mukesh,Varghese Saju,Singh Bhim Pratap,Gogoi Dip K,Kumar Rakesh,Arora Dilip K The Korean Society of Plant Pathology 2006 Plant Pathology Journal Vol.22 No.4

Riboflavin caused induction of systemic resistance in chickpea against Fusarium wilt and charcoal rot diseases. The dose effect of 0.01 to 20 mM riboflavin showed that 1.0 mM concentration was sufficient for maximum induction of resistance; higher concentration did not increase the effect. At this concentration, riboflavin neither caused cell death of the host plant nor directly affected the pathogen's growth. In time course observation, it was observed that riboflavin treated chickpea plants were inducing resistance 2 days after treatment and reached its maximum level from 5 to 7 days and then decreased. Riboflavin had no effect on salicylic acid(SA) levels in chickpea, however, riboflavin induced plants found accumulation of phenols and a greater activities of phenylalanine ammonia lyase(PAL) and pathogenesis related(PR) protein, peroxidase was observed in induced plant than the control. Riboflavin pre-treated plants challenged with the pathogens exhibited maximum activity of the peroxidases 4 days after treatment. Molecular weight of the purified peroxidase was 42 kDa. From these studies we demonstrated that riboflavin induced resistance is PR-protein mediated but is independent of salicylic acid.