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Papers by Parani Madasamy

BMC Genomics, 2010

Background Jatropha curcas L. is promoted as an important non-edible biodiesel crop worldwide. Ja... more Background Jatropha curcas L. is promoted as an important non-edible biodiesel crop worldwide. Jatropha oil, which is a triacylglycerol, can be directly blended with petro-diesel or transesterified with methanol and used as biodiesel. Genetic improvement in jatropha is needed to increase the seed yield, oil content, drought and pest resistance, and to modify oil composition so that it becomes a technically and economically preferred source for biodiesel production. However, genetic improvement efforts in jatropha could not take advantage of genetic engineering methods due to lack of cloned genes from this species. To overcome this hurdle, the current gene discovery project was initiated with an objective of isolating as many functional genes as possible from J. curcas by large scale sequencing of expressed sequence tags (ESTs). Results A normalized and full-length enriched cDNA library was constructed from developing seeds of J. curcas. The cDNA library contained about 1 × 106 clone...

Biochemical Systematics and Ecology, 2016

Plant Growth Regulation, 2004

Genome, 2001

The chloroplast trnS-psbC gene regions from total genomic DNA of 119 accessions from seven small ... more The chloroplast trnS-psbC gene regions from total genomic DNA of 119 accessions from seven small millet species were amplified by polymerase chain reaction (PCR) and digested with eight restriction enzymes individually as well as in combinations of two enzymes to generate restriction fragment length polymorphism (PCRRFLP). PCRRFLP with individual enzymes revealed polymorphism between only some species. However, all the species could be distinguished by using a combination of two enzymes, specifically HaeIII and MspI. PCRRFLP of 11 to 20 accessions with the same enzyme combination showed no intraspecific variation, which established that the differential banding patterns were species specific. In contrast, the same enzyme combination was not useful for differentiating different species of the genera Cajanus, Rhyncosia, Abies, Rhizophora, Ceriops, and Bruguiera, and it also revealed intraspecies variation in three species of Abies. The present study indicated that digestion of trnS...

Indian Journal of Biotechnology

Covalent attachment of ubiquitin has been implicated in mediating proteolysis of the cellular pro... more Covalent attachment of ubiquitin has been implicated in mediating proteolysis of the cellular proteins by Ubiquitin-proteasome pathway. Ubiquitin activating enzyme (E1), ubiquitin conjugating enzyme (E2), and ubiquitin protein ligase (E3) are the three enzymes involved in this process. This paper reports the isolation of a gene that codes for the ubiquitin conjugating enzyme in Avicennia marina (AmUBC2), and regulation of its expression at RNA level under salt stress. Deduced amino acid sequence of AmUBC2 showed 96% identity with UBC2 of Arabidopsis thaliana and also 73-78% identity with RAD6 DNA repair protein of Homo sapiens, Rattus norvegicus, Caenorhabditis elegans, Drosophila melanogaster, Arabidopsis thaliana and Saccharomyces cerevisiae. Multiple alignment analysis showed that the amino acid residues in the core region of UBC2 were highly conserved across different taxa in the evolutionary hierarchy. While some ubiquitin conjugating enzymes were induced under salt, heat and h...

The genus Terminalia L. belongs to the Combretaceae family, which includes several medicinal and ... more The genus Terminalia L. belongs to the Combretaceae family, which includes several medicinal and threatened species with high trade value. Species of Terminalia in India belong to four sections and species identification within the sections is considered to be complex due to the lack of sufficient taxonomical characters and the existence of morphotypes. Therefore, we tested the effectiveness of three chloroplast DNA barcodes (rbcL, matK, and trnH-psbA) and a nuclear DNA barcode (ITS2) for the discrimination of Terminalia species. A reference DNA barcode library consisting of 120 DNA barcodes from ten species of Ter-minalia was created. Intra-specific divergence was not observed among the accessions for any marker. Inter-specific divergence was highest in trnH-psbA (10.6%), followed by ITS2, matK and rbcL markers. The success of species differentiation by DNA barcodes was 100% with trnH-psbA, 80% with matK and ITS2, and 10% with rbcL. In the phylogenetic trees, the rbcL marker did no...

Agronomy

Engineering transcription factors (TF) hold promise in enhancing abiotic stress tolerance in plan... more Engineering transcription factors (TF) hold promise in enhancing abiotic stress tolerance in plants. In this study, one of the popular rice varieties of South India, namely ADT 43, was engineered with a TF AtDREB1A driven by a stress-inducible rd29A promoter. PCR and Southern hybridization were employed to confirm the integration and copy number of the transgene. Transgenic lines (T1) of ADT 43 showed enhanced tolerance to drought and salinity compared to the non-transgenic ADT 43. Transgenic lines were found to maintain higher RWC %, lower leaf temperature, and partially closed stomata, enabling better survival under stress conditions. qRT-PCR analysis revealed the strong induction of AtDREB1A transcripts during drought. Transgenic lines of ADT 43 exhibited increased germination and retention of chlorophyll in their leaves under salinity. Evaluation of transgenic lines under transgenic screen house conditions revealed that line # A16 exhibited on par agronomic performance against i...

Canadian Journal of Biotechnology

Computational Biology and Chemistry

Frontiers in Plant Science, 2016

Genome, 2016

Plants are the major source of therapeutic ingredients in complementary and alternative medicine ... more Plants are the major source of therapeutic ingredients in complementary and alternative medicine (CAM). However, species adulteration in traded medicinal plant raw drugs threatens the reliability and safety of CAM. Since morphological features of medicinal plants are often not intact in the raw drugs, DNA barcoding was employed for species identification. Adulteration in 112 traded raw drugs was tested after creating a reference DNA barcode library consisting of 1452 rbcL and matK barcodes from 521 medicinal plant species. Species resolution of this library was 74.4%, 90.2%, and 93.0% for rbcL, matK, and rbcL + matK, respectively. DNA barcoding revealed adulteration in about 20% of the raw drugs, and at least 6% of them were derived from plants with completely different medicinal or toxic properties. Raw drugs in the form of dried roots, powders, and whole plants were found to be more prone to adulteration than rhizomes, fruits, and seeds. Morphological resemblance, co-occurrence, m...

Recombinant human platelet-derived growth factor-BB (rhPDGF-BB) is used to treat diabetic foot ul... more Recombinant human platelet-derived growth factor-BB (rhPDGF-BB) is used to treat diabetic foot ulcers and is being investigated for use in other chronic ulcers, non-healing wounds and periodontal defects. The codon optimized hPDGF-BB was cloned in pET 28a+ and was transformed in BL21 (DE3) strain. The expression of gene was confirmed by IPTG induction. This project aims to purify the rhPDGF-BB from Escherichia coli. rhPDGF-BB is exclusively found in inclusion bodies (IBs), representing approximately 30% of the total cell proteins. The inclusion bodies were extracted by disrupting E.coli cells by sonication. Approximately 14.5 kDa PDGF-B monomer was isolated from inclusion bodies and was solubilized by 6M guanidine HCl. The solubilized PDGF-B monomer was dialyzed to yield 29 kDa dimeric PDGF-BB. 60 µg of rhPDGF-BB per 100 ml of E. coli culture was obtained.

The current study was an attempt to understand the regulation of nicotine biosynthesis due to des... more The current study was an attempt to understand the regulation of nicotine biosynthesis due to desiccation and meristem topping in Nicotiana tabacum cv. Petite Havana. Our results showed that desiccation induced silencing of Putrescine N-Methyl Transferase 2 (PMT2) (EC 2.1.1.53), a rate limiting enzyme in the nicotine biosynthetic pathway, regulates nicotine levels in tobacco. A hairpin siRNA (hpsiRNA) was designed and expressed against pmt using a stress inducible promoter rd29A from Arabidopsis thaliana. Stable transgenic RNAi lines, developed by Agrobacterium mediated transformation, showed reduced accumulation of nicotine due to desiccation and topping. The increase in the nicotine level in wild type was 115% while in RNAi lines, RNAi1, RNAi2 and RNAi3 the increase was 19.9%, 30% and 21.62%, respectively, due to desiccation. Furthermore, meristem topping of desiccated plants increased nicotine accumulation by 38% in wild type and only 7–9% in RNAi lines. No secondary surge in any...

Journal of Genetics and Genomics, 2015