@article { ISI:000268401300001, title = {Responses of midgut amylases of Helicoverpa armigera to feeding on various host plants}, journal = {Journal of Insect Physiology}, volume = {55}, number = {8}, year = {2009}, month = {AUG}, pages = {663-670}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Midgut digestive amylases and proteinases of Helicoverpa armigera, a polyphagous and devastating insect pest of economic importance have been studied. We also identified the potential of a sorghum amylase inhibitor against H. armigera midgut amylase. Amylase activities were detected in all the larval instars, pupae, moths and eggs; early instars had lower amylase levels which steadily increased up to the sixth larval instar. Qualitative and quantitative differences in midgut amylases of H. amigera upon feeding on natural and artificial diets were evident. Natural diets were categorized as one or more members of legumes, vegetables, flowers and cereals belonging to different plant families. Amylase activity and isoform patterns varied depending on host plant and/or artificial diet. Artificial diet-fed H. armigera larvae had comparatively high amylase activity and several unique amylase isoforms. Correlation of amylase and proteinase activities of H. armigera with the protein and carbohydrate content of various diets suggested that H. armigera regulates the levels of these digestive enzymes in response to macromolecular composition of the diet. These adjustments in the digestive enzymes of H. armigera may be to obtain better nourishment from the diet and avoid toxicity due to nutritional imbalance. H. armigera, a generalist feeder experiences a great degree of nutritional heterogeneity in its diet. An investigation of the differences in enzyme levels in response to macronutrient balance and imbalance highlight their importance in insect nutrition. (C) 2009 Elsevier Ltd. All rights reserved.

}, keywords = {Amylase inhibitors, Diet, Helicoverpa armigera larvae, Midgut amylase, Proteinases}, issn = {0022-1910}, doi = {10.1016/j.jinsphys.2009.05.004}, author = {Kotkar, Hemlata M. and Sarate, Priya J. and Tamhane, Vaijayanti A. and Gupta, Vidya S. and Giri, Ashok P.} } @article { ISI:000267478600011, title = {Spatial and temporal expression patterns of diverse Pin-II proteinase inhibitor genes in Capsicum annuum Linn}, journal = {Gene}, volume = {442}, number = {1-2}, year = {2009}, month = {AUG}, pages = {88-98}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Pin-II type proteinase inhibitor (PI) genes were cloned from fruit and stem tissues of Capsicum annuum L var Phule Jyoti using primers designed from reported CanPI gene sequence (AF039398). In total, 21 novel CanPIs, members of the Pin-II PI family, were identified in the study, with three isoforms of 1-inhibitory repeat domain (IRD), eight isoforms of 2-IRD), three isoforms of 3-IRD, five isoforms of 4-IRD and two partial CanPI sequences. Most of the sequences showed variation (2 to 20\%) in the deduced AA sequences which were pronounced close to the reactive site loop. Expression patterns of CanPIs in the fruit and stem tissues of mature C. annuum plants were shown to vary qualitatively and quantitatively using semi-quantitative RT-PCR expression analysis. In the fruit tissue. CanPIs with different IRDs (from 1 to 4) were expressed simultaneously. In stem tissue, 1- and 2-IRD CanPIs were strongly expressed along moderate expression of 3- and 4-IRD genes. Analysis of CanPI protein activity showed a range of active forms across the tissues. CanPI expression was differentially up-regulated upon wounding and insect attack. Although infestation by aphids (Myzus persicae) and lepidopteran pests (Spodoptera litura) specifically induced 4-IRD CanPIs, virus-infected leaves did not affect CanPI expression. Analysis of CanPI protein activity indicated that the up-regulation in CanPI expression was not always correlated with increase in PI activity. Our results demonstrated that CanPI expression is regulated spatially, temporally as well as qualitatively and quantitatively. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {CanPI, Capsicum annuum, Endogenous role, Pin-II, Plant defense, Proteinase inhibitor}, issn = {0378-1119}, doi = {10.1016/j.gene.2009.04.012}, author = {Tamhane, Vaijayanti A. and Giri, Ashok P. and Kumar, Pavan and Gupta, Vidya S.} } @article { ISI:000281054300011, title = {Interaction of recombinant CanPIs with helicoverpa armigera gut proteases reveals their processing patterns, stability and efficiency}, journal = {Proteomics}, volume = {10}, number = {15}, year = {2010}, month = {JUL}, pages = {2845-2857}, publisher = {WILEY-V C H VERLAG GMBH}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Six diverse representative Capsicum annuum (common name: hot pepper; Solanaceae) protease inhibitor genes, viz CanPI-5, -7, -13, -15, -19, and 22 comprising 1-4 inhibitory repeat domains (IRDs), were cloned and expressed in Pichia pastoris. The recombinant proteins were evaluated for their interactions with bovine trypsin, chymotrypsin, and Helicoverpa armigera gut proteases (HGP) using electrophoretic (native and denaturing) and mass spectrometric (MALDI-TOF-MS in combination with intensity fading assays) techniques. These techniques allow qualitative and semiquantitative analysis of multiple and processed IRDs of purified recombinant Capsicum annuum proteinase inhibitor (rCanPI) proteins. rCanPIs showed over 90\% trypsin inhibition, varying chymotrypsin inhibition depending on the number of respective IRDs and over 60\% inhibition of total HGP. rCanPI-15 that has only one IRD showed exceptionally low inhibition of these proteases. Interaction studies of rCanPIs with proteases using intensity fading-MALDI-TOF-MS revealed gradual processing of multi-IRD rCanPIs into single IRD forms by the action of HGP at the linker region, unlike their interactions with trypsin and chymotrypsin. Intensity fading-MALDI-TOF-MS assay showed that CanPI-13 and -15, possessing single IRD and expressed predominantly in stem tissue are degraded by HGP; indicating their function other than defense. In vitro and in vivo studies on rCanPI-5 and -7 showed maximum inhibition of HGP isoforms and their processed IRDs were also found to be stable in the presence of HGP. Even single amino acid variations in IRDs were found to change the HGP specificity like in the case of HGP-8 inhibited only by IRD-12. The presence of active PI in insect gut might be responsible for changed HGP profile. rCanPI-5 and -7 enhanced HGP-7, reduced HGP-4, -5, -10 expression and new protease isoforms were induced. These results signify isoform complexity in plant PIs and insect proteases.

}, keywords = {CanPI, H. armigera gut proteases, Intensity fading MALDI-TOF-MS, Pin-II, Plant proteomics, Plant-insect interaction}, issn = {1615-9853}, doi = {10.1002/pmic.200900853}, author = {Mishra, Manasi and Tamhane, Vaijayanti A. and Khandelwal, Neha and Kulkarni, Mahesh J. and Gupta, Vidya S. and Giri, Ashok P.} } @article { ISI:000307207300023, title = {Enhanced permeation, leaf retention, and plant protease inhibitor activity with bicontinuous microemulsions}, journal = {Journal of Colloid and Interface Science}, volume = {383}, year = {2012}, month = {OCT}, pages = {177-183}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

Bicontinuous microemulsions (BCMEs) have excellent solubulizing properties along with low interfacial tension and aqueous content that can be controlled. In this work, water soluble plant protease inhibitor (PI), well characterized for its activity against insect pests, was incorporated into a BCME system and explored for permeation on hydrophobic leaf surfaces and protease inhibition activity. The bicontinuous nature of the microemulsion containing water:2-propanol:1-butanol (55:35:10 w/w) was characterized using conductivity and self-diffusion coefficient measurements. The PI was soluble in the water-rich bicontinuous domains, stable in the microemulsions, and protease inhibition activity was retained for a prolonged duration. The microemulsions ensured greater wettability and a wider spread of the PI on hydrophobic leaf surfaces as revealed by contact angle measurements. Significantly, trypsin inhibition activity assays of the PI recovered from the leaves after delivery from the microemulsion indicated a significant increase in the PI retention on the leaf. This BCME enabled greater leaf permeation and retention of the PI can be attributed to a temporary disruption of the waxy leaf surface followed by self-repair without causing any long term damage to the plant. (C) 2012 Elsevier Inc. All rights reserved.

}, keywords = {Bicontinuous microemulsion, Biopesticide, Microemulsion pesticide, protease inhibitor, Protein encapsulation, Protein permeation}, issn = {0021-9797}, doi = {10.1016/j.jcis.2012.06.025}, author = {Tamhane, Vaijayanti A. and Dhaware, Deepika G. and Khandelwal, Neha and Giri, Ashok P. and Panchagnula, Venkateswarlu} } @article { ISI:000311804700002, title = {Stress inducible proteinase inhibitor diversity in capsicum annuum}, journal = {BMC Plant Biology}, volume = {12}, year = {2012}, month = {NOV}, pages = {217}, publisher = {BIOMED CENTRAL LTD}, address = {236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND}, abstract = {

Background: Wound-inducible Pin-II Proteinase inhibitors (PIs) are one of the important plant serine PIs which have been studied extensively for their structural and functional diversity and relevance in plant defense against insect pests. To explore the functional specialization of an array of Capsicum annuum (L.) proteinase inhibitor (CanPIs) genes, we studied their expression, processing and tissue-specific distribution under steady-state and induced conditions. Inductions were performed by subjecting C. annuum leaves to various treatments, namely aphid infestation or mechanical wounding followed by treatment with either oral secretion (OS) of Helicoverpa armigera or water. Results: The elicitation treatments regulated the accumulation of CanPIs corresponding to 4-, 3-, and 2-inhibitory repeat domains (IRDs). Fourty seven different CanPI genes composed of 28 unique IRDs were identified in total along with those reported earlier. The CanPI gene pool either from uninduced or induced leaves was dominated by 3-IRD PIs and trypsin inhibitory domains. Also a major contribution by 4-IRD CanPI genes possessing trypsin and chymotrypsin inhibitor domains was specifically revealed in wounded leaves treated with OS. Wounding displayed the highest number of unique CanPIs while wounding with OS treatment resulted in the high accumulation of specifically CanPI-4, -7 and -10. Characterization of the PI protein activity through two dimensional gel electrophoresis revealed tissue and induction specific patterns. Consistent with transcript abundance, wound plus OS or water treated C. annuum leaves exhibited significantly higher PI activity and isoform diversity contributed by 3- and 4-IRD CanPIs. CanPI accumulation and activity was weakly elicited by aphid infestation yet resulted in the higher expression of CanPI-26, -41 and -43. Conclusions: Plants can differentially perceive various kinds of insect attacks and respond appropriately through activating plant defenses including regulation of PIs at transcriptional and post-translational levels. Based on the differentially elicited CanPI accumulation patterns, it is intriguing to speculate that generating sequence diversity in the form of multi-IRD PIs is a part of elaborative plant defense strategy to obtain a diverse pool of functional units to confine insect attack.

}, keywords = {CanPI, Herbivory, Oral secretions, Pin-II type proteinase inhibitors, Plant-insect interaction}, issn = {1471-2229}, doi = {10.1186/1471-2229-12-217}, author = {Mishra, Manasi and Mahajan, Neha S. and Tamhane, Vaijayanti A. and Kulkarni, Mahesh J. and Baldwin, Ian T. and Gupta, Vidya S. and Giri, Ashok P.} } @article {42623, title = {Plasticity of protease gene expression in helicoverpa armigera upon exposure to multi-domain capsicum annuum protease inhibitor}, journal = {Biochimica et Biophysica Acta (BBA) - General Subjects}, volume = {1830}, year = {2013}, month = {MAR}, pages = {3414{\textendash}3420}, abstract = {

Background A multi-domain Pin-II type protease inhibitor from Capsicum annuum (CanPI-7) is known to be effective against the insect pest, Helicoverpa armigera. The present study is an attempt to investigate the optimal dose of recombinant CanPI-7 (rCanPI-7) for effective antibiosis to H. armigera and further to characterize the responses of digestive proteases upon rCanPI-7 ingestion. Methods The gut protease activity was assessed biochemically and transcript accumulation pattern for selected trypsin and chymotrypsin genes was analyzed by quantitative Real-Time PCR. Results The growth retardation upon exposure to rCanPI-7 was more prominent in neonates as compared to third instar larvae. Influence of stage and dosage of rCanPI-7 was conspicuous on the expression and regulation of candidate trypsin and chymotrypsin genes in H. armigera. The transcript accumulation pattern correlated with the protease activity in rCanPI-7 exposed larvae. Conclusions We conclude that early exposure and specific dose of protease inhibitor are essential for effective antibiosis despite the large diversity and plasticity in the expression of protease genes in H. armigera. Moreover, it is also evident that the regulation and expression of H. armigera gut proteases are specific to the stage of PI exposure. General significance These results highlight the requirement of optimal PI concentration for effective growth retardation and for inhibiting the major gut proteases of H. armigera.

}, doi = {10.1016/j.bbagen.2013.03.017}, author = {Mahajan, Neha S. and Mishra, Manasi and Tamhane, Vaijayanti A. and Gupta, Vidya S. and Giri, Ashok P.} } @article { ISI:000327236600002, title = {Remarkable efficiency of a pin-II proteinase inhibitor sans two conserved disulfide bonds is due to enhanced flexibility and hydrogen bond density in the reactive site loop}, journal = {Journal of Biomolecular Structure \& Dynamics}, volume = {32}, number = {1}, year = {2014}, month = {JAN}, pages = {13-26}, publisher = {TAYLOR \& FRANCIS INC}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

Capsicum annuum (L.) expresses diverse potato type II family proteinase inhibitors comprising of inhibitory repeat domain (IRD) as basic functional unit. Most IRDs contain eight conserved cysteines forming four disulfide bonds, which are indispensible for their stability and activity. We investigated the functional significance of evolutionary variations in IRDs and their role in mediating interaction between the inhibitor and cognate proteinase. Among the 18 IRDs encoded by C. annuum, IRD-7, -9, and -12 were selected for further characterization on the basis of variation in their reactive site loop, number of conserved cysteine residues, and higher theoretical G(bind) for interaction with Helicoverpa armigera trypsin. Moreover, inhibition kinetics showed that IRD-9, despite loss of some of the disulfide bonds, was a more potent proteinase inhibitor among the three selected IRDs. Molecular dynamic simulations revealed that serine residues in the place of cysteines at seventh and eighth positions of IRD-9 resulted in an increase in the density of intramolecular hydrogen bonds and reactive site loop flexibility. Results of the serine residues chemical modification also supported this observation and provided a possible explanation for the remarkable inhibitory potential of IRD-9. Furthermore, this natural variant among IRDs showed special attributes like stability to proteolysis and synergistic inhibitory effect on other IRDs. It is likely that IRDs have coevolved selective specialization of their structure and function as a response towards specific insect proteases they encountered. Understanding the molecular mechanism of pest protease-plant proteinaceous inhibitor interaction will help in developing effective pest control strategies.An animated interactive 3D complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:39

}, keywords = {Capsicum annuum, Helicoverpa armigera, Proteases, Proteinase inhibitor}, issn = {0739-1102}, doi = {10.1080/07391102.2012.745378}, author = {Joshi, Rakesh S. and Mishra, Manasi and Tamhane, Vaijayanti A. and Ghosh, Anirban and Sonavane, Uddhavesh and Suresh, C. G. and Joshi, Rajendra and Gupta, Vidya S. and Giri, Ashok P.} } @article { ISI:000331848900023, title = {Stress inducible proteomic changes in capsicum annuum leaves}, journal = {Plant Physiology and Biochemistry}, volume = {74}, year = {2014}, month = {JAN}, pages = {212-217}, publisher = {ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER}, address = {23 RUE LINOIS, 75724 PARIS, FRANCE}, abstract = {

Herbivore attack induces defense responses in plants, activating several signaling cascades. As a result, molecules deterrent to the herbivores are produced and accumulated in plants. Expression of defense mechanism/traits requires reorganization of the plant metabolism, redirecting the resources otherwise meant for growth. In the present work, protein profile of Capsicum annuum leaves was examined after herbivore attack/induction. Majority of proteins identified as differentially accumulated, were having roles in redox metabolism and photosynthesis. For example, superoxide dismutase and NADP oxidoreductase were upregulated by 10- and 6-fold while carbonic anhydrase and fructose-1,6-bisphosphatase were downregulated by 9- and 4-fold, respectively. Also, superoxide dismutase, NADPH quinone oxidoreductase and NADP dependent isocitrate dehydrogenase transcripts showed a higher accumulation in induced leaf tissues at early time points. In general, proteins having role in defense and damage repair were upregulated while those involved in photosynthesis appeared downregulated. Thus metabolic reconfiguration to balance defense and tolerance was evident in the stress-induced leaves. (C) 2013 Elsevier Masson SAS. All rights reserved.

}, keywords = {Capsicum annuum, Oxidative stress, Wounding}, issn = {0981-9428}, doi = {10.1016/j.plaphy.2013.11.017}, author = {Mahajan, Neha S. and Mishra, Manasi and Tamhane, Vaijayanti A. and Gupta, Vidya S. and Giri, Ashok P.} }