Sterol glycosyltransferases-identification of members of gene family and their role in stress in Withania somnifera

Chaturvedi, Pankaj; Mishra, Manoj Kumar; Akhtar, Nehal; Gupta, Parul; Mishra, Pratibha; Tuli, Rakesh

doi:10.1007/s11033-012-1841-3

Cited by 43 publications

(52 citation statements)

References 66 publications

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“…9 Recent results obtained with functional characterization of plant GTs indicated that glycosyltransferases might play an important role in plant growth, development and interaction with the environment. 10 Moreover, the gene expression data from Genome Cluster Database suggested that TTG15/ UGT80B1 transcripts were up-regulated by cold stress.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Arabidopsis sterol glycosyltransferase TTG15/UGT80B1 role during freeze and heat stress

Mishra

Singh

Tiwari

et al. 2015

Plant Signaling & Behavior

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Sterol glycosyltransferases regulate the properties of sterols by catalyzing the transfer of carbohydrate molecules to the sterol moiety for the synthesis of steryl glycosides and acyl steryl glycosides. We have analyzed the functional role of TTG15/UGT80B1 gene of Arabidopsis thaliana in freeze/thaw and heat shock stress using T-DNA insertional sgt knockout mutants. Quantitative study of spatial as well as temporal gene expression showed tissue-specific and dynamic expression patterns throughout the growth stages. Comparative responses of Col-0, TTG15/UGT80B1 knockout mutant and p35S:TTG15/UGT80B1 restored lines were analyzed under heat and freeze stress conditions. Heat tolerance was determined by survival of plants at 42 C for 3 h, MDA analysis and chlorophyll fluorescence image (CFI) analysis. Freezing tolerance was determined by survival of the plants at -1 C temperature in non-acclimatized (NA) and cold acclimatized (CA) conditions and also by CFI analysis, which revealed that, p35S:TTG15/UGT80B1 restored plants were more adapted to freeze stress than TTG15/UGT80B1 knockout mutant under CA condition. HPLC analysis of the plants showed reduced sterol glycoside in mutant seedlings as compared to other genotypes. Following CA condition, both b-sitosterol and sitosterol glycoside quantity was more in Col-0 and p35S:TTG15/UGT80B1 restored lines, whereas it was significantly less in TTG15/UGT80B1 knockout mutants. From these results, it may be concluded that due to low content of free sterols and sterol glycosides, the physiology of mutant plants was more affected during both, the chilling and heat stress.

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Section: Introductionmentioning

confidence: 99%

Characterization of Arabidopsis sterol glycosyltransferase TTG15/UGT80B1 role during freeze and heat stress

Mishra

Singh

Tiwari

et al. 2015

Plant Signaling & Behavior

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“…L [4], Solanum melongena [26], and Arabidopsis thaliana [27]. Furthermore, three members belonging to the SGT family were identified and their relative expression has been monitored in different organs of W. somnifera as well as analyzed as a response to external stimuli [14]. Three SGTs have been identified and isolated by degenerate primers which initiated PCR followed by RACE (rapid amplification of cDNA ends) approach.…”

Section: Introductionmentioning

confidence: 99%

“…Elicitor treatments, namely, methyl jasmonate and salicylic acid have been shown to enhance the expression of SGT genes by up to 10-fold suggesting their possible role in defense mechanisms. Furthermore, the expression of SGTs increased on exposure to cold and heat stress highlighting the modification of sterols in abiotic stress mechanisms [14]. Recently, studies on WsSGTL1 from W. somnifera demonstrated to enhance salt tolerance, heat tolerance, and cold acclimatization when overexpressed in transgenic Arabidopsis plant.…”

Section: Introductionmentioning

confidence: 99%

“…SGs are sugar derivatives of membrane associated sterols and are comprised of a sugar moiety attached to the hydroxyl (−OH) group at the C-3 of a sterol molecule which includes a planar sterol backbone formed by four condensed aliphatic rings and a hydrocarbon side chain at C-17 position [14–16, 20, 26–29]. The studies have suggested that steryl glycosides serve as precursors of defense compounds such as saponins, glycoalkaloids, or avenacosides due to the presence of sugar moieties at various hydroxyl groups [30], C-3 OH position being the most preferred one by SGTs for enzymatic catalysis, followed by 27 β -OH position or hydroxyl group present at the side chain of a modified sterol backbone.…”

Section: Introductionmentioning

confidence: 99%

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Molecular Cloning and Biochemical Characterization of a Recombinant Sterol 3-O-Glucosyltransferase fromGymnema sylvestreR.Br. Catalyzing Biosynthesis of Steryl Glucosides

Tiwari

Sangwan

Asha

et al. 2014

BioMed Research International

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Gymnema sylvestre R.Br., a pharmacologically important herb vernacularly called Gur-Mar (sugar eliminator), is widely known for its antidiabetic action. This property of the herb has been attributed to the presence of bioactive triterpene glycosides. Although some information regarding pharmacology and phytochemical profiles of the plant are available, no attempts have been made so far to decipher the biosynthetic pathway and key enzymes involved in biosynthesis of steryl glucosides. The present report deals with the identification and catalytic characterization of a glucosyltransferase, catalyzing biosynthesis of steryl glycosides. The full length cDNA (2572 bp) contained an open reading frame of 2106 nucleotides that encoded a 701 amino acid protein, falling into GT-B subfamily of glycosyltransferases. The GsSGT was expressed in Escherichia coli and biochemical characterization of the recombinant enzyme suggested its key role in the biosynthesis of steryl glucosides with catalytic preference for C-3 hydroxyl group of sterols. To our knowledge, this pertains to be the first report on cloning and biochemical characterization of a sterol metabolism gene from G. sylvestre R.Br. catalyzing glucosylation of a variety of sterols of biological origin from diverse organisms such as bacteria, fungi, and plants.

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“…Genes marked by the red bar mainly take part in the physiological processes of hydrolysis reactions and signal transduction. Genes in the purple group were mainly involved in transcriptional regulation and stress response involving the production of chemical defense components, such as sterols (Kohara et al, 2005; Chaturvedi et al, 2012), which are part of the stress response in D. nipponica ; this is consistent with their high expression in the rhizomes, which are the tissue richest in dioscin.…”

Section: Resultsmentioning

confidence: 62%

Weighted Gene Co-expression Network Analysis of the Dioscin Rich Medicinal Plant Dioscorea nipponica

et al. 2017

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Dioscorea contains critically important species which can be used as staple foods or sources of bioactive substances, including Dioscorea nipponica, which has been used to develop highly successful drugs to treat cardiovascular disease. Its major active ingredients are thought to be sterol compounds such as diosgenin, which has been called “medicinal gold” because of its valuable properties. However, reliance on naturally growing plants as a production system limits the potential use of D. nipponica, raising interest in engineering metabolic pathways to enhance the production of secondary metabolites. However, the biosynthetic pathway of diosgenin is still poorly understood, and D. nipponica is poorly characterized at a molecular level, hindering in-depth investigation. In the present work, the RNAs from five organs and seven methyl jasmonate treated D. nipponica rhizomes were sequenced using the Illumina high-throughput sequencing platform, yielding 52 gigabases of data, which were pooled and assembled into a reference transcriptome. Four hundred and eighty two genes were found to be highly expressed in the rhizomes, and these genes are mainly involved in stress response and transcriptional regulation. Based on their expression patterns, 36 genes were selected for further investigation as candidate genes involved in dioscin biosynthesis. Constructing co-expression networks based on significant changes in gene expression revealed 15 gene modules. Of these, four modules with properties correlating to dioscin regulation and biosynthesis, consisting of 4,665 genes in total, were selected for further functional investigation. These results improve our understanding of dioscin biosynthesis in this important medicinal plant and will help guide more intensive investigations.

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Sterol glycosyltransferases-identification of members of gene family and their role in stress in Withania somnifera

Cited by 43 publications

References 66 publications

Characterization of Arabidopsis sterol glycosyltransferase TTG15/UGT80B1 role during freeze and heat stress

Characterization of Arabidopsis sterol glycosyltransferase TTG15/UGT80B1 role during freeze and heat stress

Molecular Cloning and Biochemical Characterization of a Recombinant Sterol 3-O-Glucosyltransferase fromGymnema sylvestreR.Br. Catalyzing Biosynthesis of Steryl Glucosides

Weighted Gene Co-expression Network Analysis of the Dioscin Rich Medicinal Plant Dioscorea nipponica

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