Papers by Dr. Pradeep Kumar
Role of endochitinase (ech42) gene in Trichoderma was worked out to prove the efficacy against mo... more Role of endochitinase (ech42) gene in Trichoderma was worked out to prove the efficacy against most dreaded red rot disease of sugarcane caused by Colletotrichum falcatum Went. Trichoderma spp. along with Trichoderma harzianum strain and Aspergillus awamori were tested against the virulent pathotypes of C. falcatum (Cf08, Cf09 and Cf401) under in vitro and in vivo conditions. T. harzianum was significantly able to control the incidence of red rot disease in highly susceptible sugarcane cultivar. PCR-Random amplified polymorphic DNA amplification results clearly separated T. harzianum 1, 2 and 3 from rest of the biological agents. T. harzianum 1 strain was highly diverse and making distant relationship with rest of the T. harzianum bioagents. Wide genetic distance was observed among the red rot pathogens and biological agents. The ech42 specific primers pair amplified a corresponding fragment of 1.5 kb in all Trichoderma spp. Thus, the presence of the ech42 gene was found to be correlated with the biocontrol activity of Trichoderma species. These findings clearly supported that ech42 gene is more specifically responsible for controlling the red rot incidence in sugarcane.
Sugarcane is one of the most important crops for the sugar production in India and Uttar Pradesh ... more Sugarcane is one of the most important crops for the sugar production in India and Uttar Pradesh (UP) is the top on sugarcane while second in sugar production. Many biotic and abiotic stresses affected the sugarcane production among the reported diseases of sugarcane; Pokkah boeng is now playing a very important role due to its economic threats in UP. Recent survey during 2007-13 showed increasing trend of disease incidence and most of the commercial cultivars affected by the disease ranged from 1%-90%. Although Pokkah boeng comes under minor concern but these days it is going to be major on basis of their rapid epidemiology during last few years. Nowadays, the incidence and severity of Pokkah boeng disease has been reported from major sugarcane growing states like Uttar Pradesh, Maharashtra, Punjab, Haryana, Assam, Tamil Nadu and Bihar in India and other sugarcane growing countries. Keeping in view the seriousness of the problem, the present review summarise the distribution, establish a suitable genetic base and disease management practices through various approaches.
Journal of Horticultural …, 2012
Archives Of Phytopathology …, 2012
Malformation disease of Mango (Mangifera indica L.) caused by Fusarium moniliforme var. subglutin... more Malformation disease of Mango (Mangifera indica L.) caused by Fusarium moniliforme var. subglutinans is one of the most destructive diseases, which is a major production constraint in the mango-growing regions of India. In this study, The bioagents Trichoderma viride (Tr1), Trichoderma virens (Tr2) and Trichoderma harzianum (Tr3) were evaluated in culture with the pathogens to monitor the antagonistic effect and their volatile compound and culture filtrates (non-volatile compound). It was found that all the three isolates of bioagents significantly checked the growth of F. moniliforme var. subglutinans. In dual culture, the best result was obtained with T. harzianum followed by T. virens and T. viride. A similar result was also observed in the case of culture filtrates ofTrichoderma spp. The results clearly showed that inhibition of the growth of the fusaria isolates by T. harzianum was significantly superior to T. viride andT.virens. In case of antifungal activity of volatile compounds released by Trichoderma isolates, it was also observed that T. virens was more superior to T.harzianum and T. viride.
Plant Knowledge …, 2012
Sugarcane, being one of the most important cash crop of India, is being widely cultivated in seve... more Sugarcane, being one of the most important cash crop of India, is being widely cultivated in several parts of the country. Like other crops of economic importance, sugarcane is also threatened by several diseases. Diseases caused by fungus, bacteria, viruses and phytoplasmas pose a serious threat to sugarcane cultivation which adversely affect the cane yield and sugar recovery in different sugarcane growing regions. Among the Bacterial diseases Ratoon Stunting Disease (RSD) results in severe losses in cane yield and quality attributes. RSD has been identified from different regions of the world using serological and molecular tools. In this article, information on occurrence, symtomatology, molecular characterization, transmission, and management approaches regarding RSD has been reviewed.
RNA interference mediated gene silencing is a knock down technology that brings revolution in fun... more RNA interference mediated gene silencing is a knock down technology that brings revolution in functional genomics and has great promises for new applications of commercial value in crop improvement. Although the technology is still in its infancy and many mysteries of RNAi have yet to unfold, but the new field of RNAi based on genomics is increasingly being qualified as a fundamental paradigm shift for biotechnology and future genomics. The principle behind RNAi is that it starts with introduction of a dsDNA in cell, followed by activation of DICER gene and RISC complex, which eventually leads to loss of gene expression. An important aspect of silencing in plants is that it can be triggered locally and then spread via a mobile silencing signal. RNAi technology may be used for generating improved crop varieties in terms of disease resistance, insect resistance, enhancing nutritional qualities, shelf life and abiotic stress tolerance as a biological tool has been employed to investigate gene function in vitro and in vivo. It is also being used for regulating genes in crop plants in a very specific manner without affecting the expression of other genes, thus increasing their productivity.
Peroxidases were isolated from Sapindus mukorossi (Reetha) and partially purified using acetone p... more Peroxidases were isolated from Sapindus mukorossi (Reetha) and partially purified using acetone precipitation, ion-exchange chromatography with a 14-fold purification, 22% recovery and a specific activity of 266 × 103 units/mg protein. Sapindus peroxidases (SPases) showed six bands after acetone precipitation and one distinct band after ion exchange chromatography on Native-PAGE after zymography. Enzymes purified by ion exchange chromatography were loaded on Sepahdex G-50 superfine column and their molecular weight was reported to be 25 kDa. They showed temperature optima at 50°C and pH optima at 5.0. km for SPases was reported to be 1.05 mM and 0.186 mM for guaiacol and H2O2 respectively. The Vmax/Km value for o-dianisidine was 449 while for H2O2 it was 5 × 105. Protocatechuic acid acts as a potent inhibitor for SPases (6.0% relative activity at 4.5 μM) but ferulic acid inhibits its activity at a much lower concentration (0.02 μM). Enzymes were stimulated by metal cations like Cu2+, Ca2+ (145, 168; percentage relative activity respectively) and showed mild inhibition (up to 20%) with Mn2+ and Mg2+. Alanine stimulated the enzyme activity (up to 33%; at 0–100 μM) while other amino acids like cysteine, methionine, tryptophan and tyrosine inhibited the SPases (13–57% at 0–100 μM).
Keywords Sapindus peroxidases – Precipitation – Purification – Kinetics – Heat stability
Preparative …, Jan 1, 2007
Ionically bound peroxidases (POD) were salt extracted from the pulp of four Indian apple varietie... more Ionically bound peroxidases (POD) were salt extracted from the pulp of four Indian apple varieties, i.e., Golden delicious HP, Golden delicious JK, Red delicious, and Royal delicious. They were precipitated with chilled ethanol. Thermal treatments of partially purified enzymes were given from 40-708C for 30 minutes. Golden delicious HP peroxidase showed thermostability at 608C, while three other peroxidases were observed at 508C. Phenolic compounds (i.e., caffeic acid, ferulic acids, p-coumaric acid, protocatechuic acid) and metal ions (i.e., Cu 2þ and Fe 2þ ) activated all apple peroxidases. However, Mn 2þ inhibited the peroxidases from Golden delicious HP, Golden delicious JK, and Red delicious, and a substantial increase was observed in Royal delicious peroxidase. Mg 2þ inhibited the peroxidases from Golden delicious HP and Red delicious, but marginal activation was reported in peroxidases from Golden delicious JK and Royal delicious. Zn 2þ established stimulation in Golden delicious HP and Golden delicious JK peroxidases, but inhibition was observed in peroxidases in Red delicious and Royal delicious. . Methionine, proline, tryptophan, and valine stimulated all four apple peroxidases, but cysteine showed inhibition in Golden delicious JK.
Physiology and Molecular Biology of Plants
The Santalum peroxidase was extracted from the leaves and precipitated with double volume of chil... more The Santalum peroxidase was extracted from the leaves and precipitated with double volume of chilled acetone. The optimum percent relative activity for the Santalum peroxidase was observed at pH 5.0 and 50°C temperature. The Santalum peroxidase per cent relative activity was stimulated in the presence of phenolic compounds like ferrulic acid and caffeic acids; however, indole-3-acetic acid (IAA) and protocatechuic acid act as inhibitors. All divalent cations Fe 2+ , Mn 2+ , Mg 2+ , Cu 2+ and Zn 2+ stimulate the relative activity of the Santalum peroxidase at concentration of 2.0 μM. Amino acids like L-alanine and L-valine activate the per cent relative activity, while L-proline and DL-methionine showed moderate inhibition for the Santalum peroxidase. However, a very low a concentration of cysteine acts as a strong inhibitor of Santalum peroxidase at the concentration of 0.4 mM. Native polyacrylamide gel electrophoresis (Native-PAGE) was performed for isoenzyme determination and two bands were observed. K m and V max values were calculated from Lineweaver-Burk graph. The apparent V max /K m value for O-dianisidine and H 2 O 2 were 400 and 5.0×105 Units/min/ mL respectively.
Physiology and Molecular …, Jan 1, 2009
A cephalosporin antibiotic, cefotaxime (Omnatax TM ) promoted somatic embryogenesis and subsequen... more A cephalosporin antibiotic, cefotaxime (Omnatax TM ) promoted somatic embryogenesis and subsequent shoot regeneration in vitro from spindle in sugarcane irrespective of the genotypes as ( CoJ 83, CoJ 88 and CoJ 64) culturered on MS medium with 2,4-D (2.5 mgl -1 ) and kinetin (0.5 mgl -1 ). Seven different concentrations of cefotaxime (100, 200, 300, 400, 500, 600 and 700 mgl -1 ) were tested to find the optimal concentration of cefotaxime for somatic embryogenesis from callus cultures. Among the three varieties, calli of variety CoJ 83 incubated on MS medium with 2,4-D (2.5 mgl -1 ) + kinetin (0.5 mgl -1 ) + cefotaxime (500 mgl -1 ) exhibited maximum somatic embryogenesis. To improve shoot regeneration, the callus was transferred to MS medium with BAP (0.5 mgl -1 ) + kinetin (0.5 mgl -1 ) in combination with different levels of cefotaxime. Highest frequency of shoot regeneration was observed in callus of CoJ 83 in the presence of 500 mgl -1 cefotaxime. The plantlets could be successfully hardened in polybags and transferred to soil, where they exhibited normal growth. Our results convincingly demonstrated that cefotaxime improves somatic embryogenesis from spindle and regeneration from embryogenic calli of sugarcane and hence can be strongly recommended for rapid and large scale multiplication of sugarcane. [Physiol. Mol. Biol. Plants 2009; 15(3) : 257-265]
American Journal of …, Jan 1, 2009
Plant Omics, Jan 1, 2009
During the last few decades, the use of molecular markers, revealing polymorphism at the DNA leve... more During the last few decades, the use of molecular markers, revealing polymorphism at the DNA level, has been playing an increasing part in plant biotechnology and their genetics studies. There are different types of markers viz. morphological, biochemical and DNA based molecular markers. These DNA based markers are differentiates in two types first non PCR based (RFLP) and second is PCR based markers (RAPD, AFLP, SSR, SNP etc.), amongst others, the microsatellite DNA marker has been the most widely used, due to its easy use by simple PCR, followed by a denaturing gel electrophoresis for allele size determination, and to the high degree of information provided by its large number of alleles per locus. Despite this, a new marker type, named SNP, for Single Nucleotide Polymorphism, is now on the scene and has gained high popularity, even though it is only a bi-allelic type of marker. Day by day development of such new and specific types of markers makes their importance in understanding the genomic variability and the diversity between the same as well as different species of the plants. In this review, we will discuss about the biochemical and molecular markers their Advantages, disadvantages and the applications of the marker in comparison with other markers types.
… of Biotechnology & …, Jan 1, 2008
Peroxidases (POD) were extracted from the leaves of Ricinus communis (castor), precipitated with ... more Peroxidases (POD) were extracted from the leaves of Ricinus communis (castor), precipitated with double volume of chilled acetone. Ricinus peroxidases showed the optimum per cent relative activity at the temperature 60 o C and pH 5.0. The Vmax/Km value for O-dianisidine was 680 Units/min/mL while for H 2 O 2 was found to be 6.5×10 5 Units/min/mL. The phenolic compounds like ferrulic acid (0.2-0.08 μM), caffeic acids, and indol 3-acetic acid (1.0-4.5 μM), activated the Ricinus peroxidases, however protocatechuic acid strongly inhibited the enzyme activity at same concentration. Ricinus peroxidases were stimulated by metal ions like Fe 2+ ,Cu 2+ , Mn 2+ , Zn 2+ and Mg 2+ (586, 193,145,145 and 103 per cent relative activity respectively) at concentration of 4.0 μM. Ricinus peroxidases were also stimulated by amino acids like L-proline and L-alanine (128 and 115 per cent relative activity respectively), while DL-Methionine and L-Valine showed strong inhibition with (68 and 80 per cent relative activity respectively) at 4.0 mM concentration.
Asian Journal of Plant Sciences
African Journal of …, Jan 1, 2010
Twenty-five isolates of Colletotrichum gloeosporioides causing mango anthracnose were collected f... more Twenty-five isolates of Colletotrichum gloeosporioides causing mango anthracnose were collected from different agroclimatic zones of India. The isolates were evaluated for their pathogenic variability on mango seedlings and genetic characterization using random amplified polymorphic DNA (RAPD molecular techniques). The random primers OPA-1, 3, 5, 9, 11, 15, 16 and 18 were used and the twentyfive isolates were grouped into two. The amplified DNA fragments (amplicons) obtained was compared by agarose gel electrophoresis. Isolate specific RAPD fingerprints were obtained. Out of eight primers in RAPD, OPA-1, 3 and 18 were able to produce reproducible banding pattern. Each of these primers generated a short spectrum of amplicons, located between 661 and 2291-bp markers, indicative of genetic polymorphism. Dendogram revealed more than 75% level of similarity. 4.36% polymorphism was also found in individual isolates that was not statistically significant (P > 0.05) among the sample, it also indicates that all the isolates tested had approximately same genetic identity. The data suggest that RAPD may be of value by virtue of its rapidity, efficiency and reproducibility in generating genetic fingerprints of C. gloeosporioides isolates.
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Papers by Dr. Pradeep Kumar
Keywords Sapindus peroxidases – Precipitation – Purification – Kinetics – Heat stability
Keywords Sapindus peroxidases – Precipitation – Purification – Kinetics – Heat stability