@article { ISI:000302335800008, title = {Trehalose as an indicator of desiccation stress in Drosophila melanogaster larvae: a potential marker of anhydrobiosis}, journal = {Biochemical and Biophysical Research Communications}, volume = {419}, number = {4}, year = {2012}, month = {MAR}, pages = {638-642}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

In the current scenario of global climate change, desiccation is considered as one of the major environmental stressors for the biota exposed to altered levels of ambient temperature and humidity. Drosophila melanogaster, a cosmopolitan terrestrial insect has been chosen as a humidity-sensitive bioindicator model for the present study since its habitat undergoes frequent stochastic and/or seasonally aggravated dehydration regimes. We report here for the first time the occurrence of anhydrobiosis in D. melanogaster larvae by subjecting them to desiccation stress under laboratory conditions. Larvae desiccated for ten hours at \<5\% relative humidity could enter anhydrobiosis and could revive upon rehydration followed by resumption of active metabolism. As revealed by FIR and HPLC analyzes, our findings strongly indicated the synthesis and accumulation of trehalose in the desiccating larvae. Biochemical measurements pointed out the desiccation-responsive trehalose metabolic pathway that was found to be coordinated in concert with the enzymes trehalose 6-phosphate synthase and trehalase. Further, an inhibitor-based experimental approach using deoxynojirimycin, a specific trehalase inhibitor, demonstrated the pivotal role of trehalose in larval anhydrobiosis of D. melanogaster. We therefore propose trehalose as a potential marker for the assessment of anhydrobiosis in Drosophila. The present findings thus add to the growing list of novel biochemical markers in specific bioindicator organisms for fulfilling the urgent need of environmental biomonitoring of climate change. (C) 2012 Elsevier Inc. All rights reserved.

}, keywords = {Anhydrobiosis, biomarker, Deoxynojirimycin, Desiccation, Drosophila melanogaster, trehalose}, issn = {0006-291X}, doi = {10.1016/j.bbrc.2012.02.065}, author = {Thorat, Leena J. and Gaikwad, Sushama M. and Nath, Bimalendu B.} } @article { ISI:000353901700002, title = {Insect trehalase: physiological significance and potential applications}, journal = {Glycobiology}, volume = {25}, number = {4}, year = {2015}, month = {APR}, pages = {357-367}, publisher = {OXFORD UNIV PRESS INC}, address = {JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA}, abstract = {

Trehalose, a non-reducing disaccharide, is widespread throughout the biological world. It is the major blood sugar in insects playing a crucial role as an instant source of energy and in dealing with abiotic stresses. The hydrolysis of trehalose is under the enzymatic control of trehalase. The enzyme trehalase is gaining interest in insect physiology as it regulates energy metabolism and glucose generation via trehalose catabolism. The two forms of insect trehalase namely, Tre-1 and Tre-2, are important in energy supply, growth, metamorphosis, stress recovery, chitin synthesis and insect flight. Insect trehalase has not been reviewed in depth and the information available is quite scattered. The present mini review discusses our recent understanding of the regulation, mechanism and biochemical characterization of insect trehalase with respect to its physiological role in vital life functions. We also highlight the molecular and biochemical properties of insect trehalase that makes it amenable to competitive inhibition by most glycosidase inhibitors. Due to its crucial role in carbon metabolism in insects, application of inhibitors against trehalose can form a promising area towards formulating strategies for insect pest control.

}, keywords = {carbohydrate metabolism, glycosidase inhibitor, glycoside hydrolase, trehalase, trehalose}, issn = {0959-6658}, doi = {10.1093/glycob/cwu125}, author = {Shukla, Ekta and Thorat, Leena J. and Nath, Bimalendu B. and Gaikwad, Sushama M.} } @article {44651, title = {Cloning and characterization of trehalase: a conserved glycosidase from oriental midge, Chironomus ramosus}, journal = {3 Biotech}, volume = {8}, year = {2018}, month = {AUG}, pages = {352}, abstract = {

Insect trehalase is a multiferous enzyme, crucial for normal physiological functions as well as under stress conditions. In this report, we present a fundamental study of the trehalase gene segment (1587 bp) from Chironomus ramosus (CrTre) encoding for 529 amino acids, using appropriate bioinformatics tools. C. ramosus, a tropical midge is an emerging animal model to investigate the consequences of environmental stresses. We observed that CrTre belongs to GH family 37 in the CAZy database and possess 57-92\% identity to dipteran trehalases. In silico characterization provided information regarding the structural, functional and evolutionary aspects of midge trehalase. In the phylogenetic tree, CrTre clustered with the soluble dipteran trehalases. Moreover, domain functional characterization of the deduced protein sequence by InterProScan (IPR001661), ProSite (PS00927 and PS00928) and Pfam (PF01204) indicated presence of highly conserved signature motifs which are important for the identification of trehalase superfamily. Furthermore, the instability index of CrTre was predicted to be \< 40 suggesting its in vivo stability while, the high aliphatic index indicated towards its thermal stability (index value 71-81). The modelled 3D tertiary structure of CrTre depicts a (alpha/alpha)(6) barrel toroidal core. The catalytic domain of the enzyme comprised Glu424 and Asp226 as the putative active site residues. Interestingly, the conserved motifs were observed to be formed by the flexible loopy regions in the tertiary structure. This study revealed essential sequence features of the midge trehalase and offers better insights into the structural aspects of this enzyme which can be correlated with its function.

}, keywords = {Conserved motifs, Homology modelling, Midges, Secondary structure, trehalose}, issn = {2190-572X}, doi = {10.1007/s13205-018-1376-y}, author = {Shukla, Ekta and Thorat, Leena and Bendre, Ameya D. and Jadhav, Santosh and Pal, Jayanta K. and Nath, Bimalendu B. and Gaikwad, Sushama M.} } @article {47003, title = {Crystal-to-crystal synthesis of helically ordered polymers of trehalose by topochemical polymerization}, journal = {Angewandte Chemie-International Edition}, volume = {59}, year = {2020}, month = {FEB}, pages = {2897-2903}, type = {Article}, abstract = {

The synthesis of crystalline helical polymers of trehalose via topochemical azide-alkyne cycloaddition (TAAC) of a trehalose-based monomer is presented. An unsymmetrical trehalose derivative having azide and alkyne crystallizes in two different forms having almost similar packing. Upon heating, both the crystals undergo TAAC reaction to form crystalline polymers. Powder X-ray diffraction (PXRD) studies revealed that the monomers in both the crystals polymerize in a crystal-to-crystal fashion; circular dichroism (CD) studies of the product crystals revealed that the formed polymer is helically ordered. This solvent-free, catalyst-free polymerization method that eliminates the tedious purification of the polymeric product exemplifies the advantage of topochemical polymerization reaction over traditional solution-phase polymerization.

}, keywords = {Click reaction, helical polymers, polysaccharide, topochemical reactions, trehalose}, issn = {1433-7851}, doi = {10.1002/anie.201914164, Early Access Date = JAN 2020}, author = {Hema, Kuntrapakam and Gonnade, Rajesh G. and Sureshan, Kana M.} } @article {47798, title = {Dietary influence on modulation of Helicoverpa armigera oral secretion composition leading to differential regulation of tomato plant defense}, journal = {Plant Science}, volume = {314}, year = {2022}, month = {JAN}, pages = {111120}, type = {Article}, abstract = {Little is known about how different plant-based diets influence the insect herbivores{\textquoteright} oral secretion (OS) composition and eventually the plant defense responses. We analyzed the OS composition of the generalist Lepidopteran insect, Helicoverpa armigera feeding on the host plant tomato (OSH), non-host plant capsicum (OSNH), and artificial diet (OSAD) using Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry. Higher numbers and levels of alkaloids and terpenoids were observed in OSH and OSNH, respectively while OSAD was rich in phospholipids. Interestingly, treatment of H. armigera OSAD, OSH and OSNH on wounded tomato leaves showed differential expression of (i) genes involved in JA and SA biosynthesis and their responsive genes, and (ii) biosynthetic pathway genes of chlorogenic acid (CGA) and trehalose, which exhibited increased accumulation along with several other plant defensive metabolites. Specifically, high levels of CGA were detected after OSH and OSNH treatments in tomato leaves. There was higher expression of the genes involved in phenylpropanoid biosynthesis, which may lead to the increased accumulation of CGA and related metabolites. In the insect bioassay, CGA significantly inhibited H. armigera larval growth. Our results underline the differential accumulation of plant and insect OS metabolites and identified potential plant metabolite(s) affecting insect growth and development.}, keywords = {Chlorogenic acid, defense, Metabolites, Non-host, Oral secretion, trehalose}, issn = {0168-9452}, doi = {https://doi.org/10.1016/j.plantsci.2021.111120}, url = {https://www.sciencedirect.com/science/article/pii/S0168945221003162}, author = {Gopal S. Kallure and Balkrishna A. Shinde and Vitthal T. Barvkar and Archana Kumari and Ashok P. Giri} } @article {48197, title = {Dietary influence on modulation of Helicoverpa armigera oral secretion composition leading to differential regulation of tomato plant defense.}, journal = {Plant Science}, volume = {314}, year = {2022}, month = {JAN}, pages = {111120}, type = {Article}, abstract = {

Little is known about how different plant-based diets influence the insect herbivores{\textquoteright} oral secretion (OS) composition and eventually the plant defense responses. We analyzed the OS composition of the generalist Lepidopteran insect, Helicoverpa armigera feeding on the host plant tomato (OSH), non-host plant capsicum (OSNH), and artificial diet (OSAD) using Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry. Higher numbers and levels of alkaloids and terpenoids were observed in OSH and OSNH, respectively while OSAD was rich in phospholipids. Interestingly, treatment of H. armigera OSAD, OSH and OSNH on wounded tomato leaves showed differential expression of (i) genes involved in JA and SA biosynthesis and their responsive genes, and (ii) biosynthetic pathway genes of chlorogenic acid (CGA) and trehalose, which exhibited increased accumulation along with several other plant defensive metabolites. Specifically, high levels of CGA were detected after OSH and OSNH treatments in tomato leaves. There was higher expression of the genes involved in phenyl-propanoid biosynthesis, which may lead to the increased accumulation of CGA and related metabolites. In the insect bioassay, CGA significantly inhibited H. armigera larval growth. Our results underline the differential accumulation of plant and insect OS metabolites and identified potential plant metabolite(s) affecting insect growth and development.

}, keywords = {Chlorogenic acid, defense, Metabolites, Non-host, Oral secretion, trehalose}, issn = {0168-9452}, doi = {10.1016/j.plantsci.2021.111120}, author = {Kallure, Gopal S. and Shinde, Balkrishna A. and Barvkar, Vitthal T. and Kumari, Archana and Giri, Ashok P.} } @article {48763, title = {Regulation of trehalose metabolism in insects: from genes to the metabolite window}, journal = {Glycobiology}, volume = {33}, year = {2023}, month = {MAY }, pages = {262-273}, type = {Review}, abstract = {

Trehalose is a major circulatory sugar in the haemolymph of insects. It provides instant energy and protection against stress. Trehalose metabolism is associated with insect growth and development. The architecture and spatio-temporal expression dynamics of trehalose metabolism and transport genes are key for regulation. These genes are controlled by various transcription factors, largely linked to nutrition, insect development, and metamorphosis. Also, trehalose levels are affected by substrate affinities and modifications of enzymes involved in the pathway. A feedback mechanism involving the precursors and products can regulate trehalose metabolism. Further, the neuroendocrine system controls trehalose levels under normal and stressed conditions by producing different hormones. Hypotrehalosemic hormones work under surplus energy conditions to activate haemolymph trehalose uptake and degradation. In contrast, hypertrehalosemic hormones stimulate trehalose production in the fat body and its transport to the haemolymph. However, trehalose metabolism regulation in insects needs to be studied in detail. This review discusses aspects of trehalose synthesis, transport, and degradation dynamics in developmental transition and stress response. Unraveling the epigenetic factors, transcriptional control and chemical or genetic modulators can provide further insights into the intricate regulation of trehalose in a development- and tissue-specific manner. This molecular information about effectors and regulators of trehalose metabolism can be applied in developing diverse biotechnological applications.

}, keywords = {Hormone, Insect development, Metabolic regulation, Stress, trehalose}, issn = {0959-6658}, doi = {10.1093/glycob/cwad011}, author = {Tellis, Meenakshi B. and Kotkar, Hemlata M. and Joshi, Rakesh S.} } @article {48306, title = {Trehalose transporter-like gene diversity and dynamics enhances stress response and recovery in Helicoverpa armigera}, journal = {Gene}, volume = {862}, year = {2023}, month = {APR}, pages = {147259}, type = {Article}, abstract = {

Trehalose is a primary sugar and its distribution across the insect body, regulated by trehalose transporters (TRETs), is essential for sugar metabolism and energy homeostasis. The large diversity of Tret-like sugar trans-porters (ST), belonging to SLC2A transporter family, in polyphagous insects probably contributes to their extremely adaptive nature. We aim to study spatio-temporal expression dynamics and functional relevance of ST transcript variants in the lepidopteran model organism, Helicoverpa armigera. Identification of 69 putative Tret-like HaST transcript variants from databases and their digital gene expression analysis indicated tissue and development-specific expression patterns. Phylogenetic and sequence similarity network analysis of HaSTs signify evolutionary divergence, while motif and structure analysis depicted conserved signatures. In vitro gene expression validation for selected genes depicts that HaST09 and 69 are fat body and haemolymph-specific. While, HaST06, 30, 36 and 57 are developmental stage or sex-specific. HaST69 has high expression in the haemolymph of fifth instar larvae. In the presence of trehalose metabolism inhibitors and abiotic stress, HaSTs expression show dysregulation, indicating their possible association with trehalose metabolism and stress re-covery. In vivo gene silencing of HaST69 resulted in reduced trehalose accumulation in the insect body, sug-gesting its plausible role in sugar metabolism. The overall understanding of HaST diversity and expression dynamics highlights their putative roles in sugar transport during adaptation and stress recovery of insects.

}, keywords = {Gene expression, Helicoverpa armigera, Stress, Transporter-like, trehalose}, issn = {0378-1119}, doi = {10.1016/j.gene.2023.147259}, author = {Tellis, Meenakshi B. and Chaudhari, Bhagyashri Y. and Deshpande, Shweta V. and Nikam, Sanika V. and Barvkar, Vitthal T. and Kotkar, Hemlata M. and Joshi, Rakesh S.} }