Comparative Cytogenetics and Fluorescent Chromosome Banding in Five Indian Species of Medik.

The genus Medik. (Subfamily: Scilloideae) has a narrow distribution in India and several overlapping morphological traits make the genus taxonomically challenging at the species level. Cytogenetic characterization can provide additional taxonomic data and can be used to evaluate genetic diversity at the species level.

 cytogenetics: a critical review on the Indian taxa.

The genus Linnaeus, 1753 (tribe Allieae) contains about 800 species worldwide of which almost 38 species are reported in India, including the globally important crops (onion, garlic, leek, shallot) and many wild species. A satisfactory chromosomal catalogue of species is missing which has been considered in the review for the species occurring in India. The most prominent base number is x=8, with few records of x=7, 10, 11.

A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa.

The cytogenetic relationships in the species of Cucurbitaceae are becoming immensely important to answer questions pertaining to genome evolution. Here, a simplified and updated data resource on cytogenetics of Cucurbitaceae is presented on the basis of foundational parameters (basic, zygotic and gametic chromosome numbers, ploidy, genome size, karyotype) and molecular cytogenetics. We have revised and collated our own findings on seven agriculturally important Indian cucurbit species in a comparative account with the globally published reports.

The -transgenic plants exhibit upregulated and gene expression.

root oncogenic locus B () is known to induce hairy roots along with triggering several physiological and morphological changes when present as a transgene. However, it is still unknown how this gene triggers these changes within the plant system. In this study, the effect of , when present as a transgene, was assessed on the gene expression levels of auxin response factors (s)-transcription factors which are key players in auxin-mediated responses.

A phylogenetic analysis of Momordica (Cucurbitaceae) in India based on karyo-morphology, nuclear DNA content and rDNA ITS1-5.8S-ITS2 sequences.

The infrageneric delimitation of Momordica, a medicinally important genus of Cucurbitaceae, is ill-defined until date. Momordica chromosomes are extremely small and are difficult to stain and visualize because of the dense cytoplasmic background. We have conducted karyomorphometric analysis by EMA method in five Indian Momordica species, and the nuclear genome sizes were estimated by flow cytometry for the first time.

Elicitation: A biotechnological tool for enhanced production of secondary metabolites in hairy root cultures.

Elicitation is a possible aid to overcome various difficulties associated with the large-scale production of most commercially important bioactive secondary metabolites from wild and cultivated plants, undifferentiated or differentiated cultures. Secondary metabolite accumulation in vitro or their efflux in culture medium has been elicited in the undifferentiated or differentiated tissue cultures of several plant species by the application of a low concentration of biotic and abiotic elicitors in the last three decades. Hairy root cultures are preferred for the application of elicitation due to their genetic and biosynthetic stability, high growth rate in growth regulator-free media, and production consistence in response to elicitor treatment.

In Vitro Propagation, Phytochemical and Neuropharmacological Profiles of (L.) Wettst.: A Review.

has been used as a reputed drug in the Indian traditional ayurvedic system for centuries. This medicinal herb with important phytopharmaceuticals has been popularly known as "Brahmi". In recent years, has been extensively studied for its bioactive constituents, constituents responsible for memory enhancing effect, and also its diverse other useful effects.

A critical review on use of Agrobacterium rhizogenes and their associated binary vectors for plant transformation.

Agrobacterium rhizogenes, along with A. tumefaciens, has been used to affect genetic transformation in plants for many years. Detailed studies conducted in the past have uncovered the basic mechanism of foreign gene transfer and the implication of Ri/Ti plasmids in this process.

A molecular phylogeny of the genus Drimia (Asparagaceae: Scilloideae: Urgineeae) in India inferred from non-coding chloroplast and nuclear ribosomal DNA sequences.

The evolutionary history of the medicinally important bulbous geophyte Drimia (subfamily: Scilloideae) has long been considered as a matter of debate in the monocot systematics. In India the genus is represented by a species complex, however, the taxonomic delimitation among them is ill-defined till date. In the present study, a comprehensive phylogenetic relationship among Indian species of this genus has been inferred for the first time based on chloroplast DNA trnL intron, rps16-trnK intergenic spacer, atpB-rbcL intergenic spacer and ribosomal DNA ITS1-5.

Transcriptome profiling of the floral buds and discovery of genes related to sex-differentiation in the dioecious cucurbit Coccinia grandis (L.) Voigt.

Dioecious species offer an inclusive structure to study the molecular basis of sexual dimorphism in angiosperms. Despite having a small genome and heteromorphic sex chromosomes, Coccinia grandis is a highly neglected dioecious species with little information available on its physical state, genetic orientation and key sex-defining elements. In the present study, we performed RNA-Seq and DGE analysis of male (MB) and female (FB) buds in C.

Biotechnological Approaches for Production of Anti-Cancerous Compounds Resveratrol, Podophyllotoxin and Zerumbone.

Secondary metabolites from numerous plant sources have been developed as anti- cancer reagents and compounds such as resveratrol, podophyllotoxin and zerumbone are of particular importance in this regard. Since their de novo chemical synthesis is both arduous and commercially expensive, there has been an impetus to develop viable, biotechnological methods of production. Accordingly, this review focuses on the recent developments in the field, highlighting the use of micropropagation, cell suspension cultures, callus cultures, hairy root cultures, recombinant microbes and genetically modified higher plants.

Micropropagation and genetic transformation of Tylophora indica (Burm. f.) Merr.: a review.

This review provides an in-depth and comprehensive overview of the in vitro culture of Tylophora species, which have medicinal properties. Tylophora indica (Burm. f.

Dynamics of sex expression and chromosome diversity in Cucurbitaceae: a story in the making.

The family Cucurbitaceae showcases a wide range of sexual phenotypes being variedly regulated by biological and environmental factors. In the present context, we have tried to assemble reports of cytogenetic investigations carried out in cucurbits accompanied by information on sex expression diversities and chromosomal or molecular basis of sex determination in dioecious (or other sexual types, if reported) taxa known so far. Most of the Cucurbitaceae tribes have mixed sexual phenotypes with varying range of chromosome numbers and hence, ancestral conditions become difficult to probe.

Chromosomal localization of 45S rDNA, sex-specific C values, and heterochromatin distribution in Coccinia grandis (L.) Voigt.

Coccinia grandis is a widely distributed dioecious cucurbit in India, with heteromorphic sex chromosomes and X-Y sex determination mode. The present study aids in the cytogenetic characterization of four native populations of this plant employing distribution patterns of 45S rDNA on chromosomes and guanine-cytosine (GC)-rich heterochromatin in the genome coupled with flow cytometric determination of genome sizes. Existence of four nucleolar chromosomes could be confirmed by the presence of four telomeric 45S rDNA signals in both male and female plants.

Molecular phylogenetic studies based on rDNA ITS, cpDNA trnL intron sequence and cladode characteristics in nine Protasparagus taxa.

The genus Asparagus comprises three subgenera of cladode bearing plants: Protasparagus, Asparagus, and Myrsiphyllum. The interspecific delimitation of the subgenus Protasparagus is ill-defined till date. In the present study, interspecific phylogenetic relationships among nine taxa of Protasparagus based on ribosomal DNA internal transcribed spacer region (ITS1-5.

Metabolic shift from withasteroid formation to phenylpropanoid accumulation in cryptogein-cotransformed hairy roots of Withania somnifera (L.) Dunal.

Cotransformed hairy roots containing a gene that encodes a fungal elicitor protein, β-cryptogein, were established in Withania somnifera, a medicinal plant widely used in Indian systems of medicine. To find out whether β-cryptogein protein endogenously elicits the pathway of withasteroid biosynthesis, withaferin A and withanolide A contents along with transcript accumulation of farnesyl pyrophosphate (FPP) synthase, 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR), and sterol glycosyltransferase (SGT) were analyzed in both cryptogein-cotransformed and normal hairy roots of W. somnifera.

Karyological relationships in Indian species of Drimia based on fluorescent chromosome banding and nuclear DNA amount.

The genus Drimia (syn. Urginea), commonly called squill, represents a species complex, infrageneric delimitation being ill-defined due to morphological variability, population variation within species and polyploidy. In the present study, fluorescent chromosome banding and measurements of nuclear DNA content by flow cytometry were performed in five Indian species of Drimia: Drimia indica, Drimia polyantha, Drimia razii, Drimia wightii and Drimia coromandeliana to elucidate taxonomic relationship and obtain possible insights into the evolutionary processes within this group.

An improved method of genome size estimation by flow cytometry in five mucilaginous species of Hyacinthaceae.

The family Hyacinthaceae constitutes about 900 species of bulbous geophytes usually characterized by high mucilage content. Taxonomic delimitation of Hyacinthaceae has been controversial since the time of Linnaeus due to the absence of reliable discriminating characters. Pattern of genome size variation can thus be considered as an added character to aid intergeneric and intrageneric relationship of the group.

Use of the cryptogein gene to stimulate the accumulation of Bacopa saponins in transgenic Bacopa monnieri plants.

Genetic transformation of the Indian medicinal plant, Bacopa monnieri, using a gene encoding cryptogein, a proteinaceous elicitor, via Ri and Ti plasmids, were established and induced bioproduction of bacopa saponins in crypt-transgenic plants were obtained. Transformed roots obtained with A. rhizogenes strain LBA 9402 crypt on selection medium containing kanamycin (100 mg l(-1)) dedifferentiated forming callus and redifferentiated to roots which, spontaneously showed shoot bud induction.

Genetic transformation of Bacopa monnieri by wild type strains of Agrobacterium rhizogenes stimulates production of bacopa saponins in transformed calli and plants.

We have developed an efficient transformation system for Bacopa monnieri, an important Indian medicinal plant, using Agrobacterium rhizogenes strains LBA 9402 and A4. Transformed roots induced by strain LBA 9402 spontaneously dedifferentiated to callus while excised roots induced by strain A4 spontaneously showed induction of shoot buds within 10 days. PCR and RT-PCR analysis revealed the presence and expression of the rolAB and rolC genes at the transcription level in pRi A4 transformed cultures indicating that the TL-DNA was integrated retained and expressed in the A4-Ri transformed shoots.

Transgenic mimicry of pathogen attack stimulates growth and secondary metabolite accumulation.

Plant secondary metabolites, including pharmaceuticals, flavorings and aromas, are often produced in response to stress. We used chemical inducers of the pathogen defense response (jasmonic acid, salicylate, killed fungi, oligosaccharides and the fungal elicitor protein, cryptogein) to increase metabolite and biomass production in transformed root cultures of the medicinal plant, Withania somnifera, and the weed, Convolvulus sepium. In an effort to genetically mimic the observed effects of cryptogein, we employed Agrobacterium rhizogenes to insert a synthetic gene encoding cryptogein into the roots of C.

Changes in morphological phenotypes and withanolide composition of Ri-transformed roots of Withania somnifera.

Developmental variability was introduced into Withania somnifera using genetic transformation by Agrobacterium rhizogenes, with the aim of changing withasteroid production. Inoculation of W. somnifera with A.