-The commercial importance of linseed (Linum usitatissimumL

Glycyrrhiza glabra L. has become an endangered medicinal plant due to the unabated extraction of glycyrrhizin. Glycyrrhizin is a triterpenoid saponin that is a root centric secondary metabolite having numerous pharmacological properties, such as anti-inflammatory, immunomodulatory, antiallergic, antiulcer, and is found to be effective even against HIV. Harvesting of the roots for high value glycyrrhizin destroys the whole plant causing existential threat to the plant itself and consequent damage to biodiversity. The present study establishes that hairy root cultures of G. glabra, using an optimized elicitor, can dramatically enhance focused production of glycyrrhizin at a much faster pace year-round without causing destruction of the plant. Hairy root cultures of G. glabra were developed using the Agrobacterium rhizogenes A4 strain. The glycyrrhizin content was enhanced using different biotic and abiotic elicitors, for example, PEG (polyethylene glycol), CdCl 2 , cellulase, and mannan at different concentrations and durations. PEG at 1% concentration enhanced the yield of glycyrrhizin up to 5.4fold after 24 h of exposure, whereas 200 µg mL −1 cellulase enhanced glycyrrhizin yield to 8.6-fold after 7 days of treatment. Mannan at 10 mg L −1 concentration enhanced the production of glycyrrhizin up to 7.8-fold after 10 days of stress. Among different antioxidant enzymes, SOD activity was significantly enhanced under drought, cellulase and mannan stress. This identification of elicitors can result in abundant supply of valuable glycyrrhizin to meet broad spectrum demand through commercial production without endangering G. glabra L.

In India, among nonedible oilseed crops, linseed is a commercial crop having tremendous economic and industrial importance. The seed production is low due to limited resources, so the development of high-yielding lines with desirable characters is urgently needed. In the present study seven parents' half diallel data was subjected to biplot analysis to identify the heterotic crosses, genetically similar parents, and to study their interrelationship. Parent Sln-Ys with A-79 and A-03 with A-79 for capsules per plant and seed yield, parent Mukta with Sln-Ys and Mukta with BAU-45 for seeds per capsule, and parents Mukta, A-103, A-79 and A-94 for test weight had lowest correlation. Parent B [Mukta] and F [A-79] were good general combiner for all the traits. The crosses F [A-79]  ×  A [Sln-Ys] and D [A-03]  ×  F [A-79] for capsules per plant, test weight and seed yield per plant, cross D [A-03]  ×  A [Sln-Ys] for capsules per plant and test weight and cross D [A-03]  ×  F [A-79] for test weight and seed yield per plant were heterotic. None of the crosses were heterotic for seeds per capsule.

Background:Rauwolfia serpentina and Solanum khasianum are well-known medicinally important plants contained important alkaloids in their different parts. Elicitation of these alkaloids is important because of associated pharmaceutical properties. Targeted metabolites were ajmaline and ajmalicine in R. serpentina; solasodine and α-solanine in S. khasianum.Objective:Enhancement of secondary metabolites through biotic and abiotic elicitors in hairy root cultures of R. serpentina and S. khasianum.Materials and Methods:In this report, hairy root cultures of these two plants were established through Agrobacterium rhizogenes mediated transformation by optimizing various parameters as age of explants, duration of preculture, and co-cultivation period. NaCl was used as abiotic elicitors in these two plants. Cellulase from Aspergillus niger was used as biotic elicitor in S. khasianum and mannan from Saccharomyces cerevisiae was used in R. serpentina.Results:First time we have reported the effect of biotic and abiotic elicitors on the production of important metabolites in hairy root cultures of these two plants. Ajmalicine production was stimulated up to 14.8-fold at 100 mM concentration of NaCl after 1 week of treatment. Ajmaline concentration was also increased 2.9-fold at 100 mg/l dose of mannan after 1 week. Solasodine content was enhanced up to 4.0-fold and 3.6-fold at 100 mM and 200 mM NaCl, respectively, after 6 days of treatments.Conclusion:This study explored the potential of the elicitation strategy in A. rhizogenes transformed cell cultures and this potential further used for commercial production of these pharmaceutically important secondary metabolites.SUMMARY Hairy roots of Rauwolfia serpentina were subjected to salt (abiotic stress) and mannan (biotic stress) treatment for 1 week. Ajmaline and ajmalicine secondary metabolites were quantified before and after stress treatmentAjmalicine yield was enhanced up to 14.8-fold at 100 mM concentration of NaCl. Ajmaline content was also stimulated 2.9-fold at 100 mg/l dose of mannan after 1 weekHairy roots of Solanum khasianum were treated with cellulase (biotic elicitor) and salt (abiotic stress)Solasodine content was improved up to 4.0-fold and 3.6-fold at 100 mM and 200 mM NaCl, respectively, after 6.days of treatmentsThe α-solanine content increased to 1.6-fold after 24 h of treatment at 100 μg/mL cellulase concentration. Abbreviations used: MS medium: Murashige and Skoog medium, B5 medium: Gamborg B5 medium, OD: Optical Density, NaCl: Sodium Chloride.

The climbers have very important role as ornamentals (e.g. Bougainvillea , Clematis , Bignonia , Lonicera , fl oribunda rose, Asparagus racemosus , Gloriosa superba , Trachelospermum jasminoides , Ceropegia spp., etc.) and as medicinal plants (e.g. Gymnema sylvestre , Tinospora cordifolia , Gloriosa superba , Asparagus racemosus , Piper betle , Holostemma ada-kodien ). But there are many problems associated with their propagation, breeding, untimely ripening of male and female fl owers, biotic and abiotic stress and also many types of diseases. Plant transformations including Agrobacterium -mediated; virus-mediated, chemical-mediated microinjection; electroporation; particle bombardment; RNAi and miRNA technologies are routinely being used for the improvement of crops, to develop desired transgenics and to introduce various types of biotic and abiotic resistance in plants. Mutation breeding is a conventional and time-consuming technique for modifying the target traits in plant systems. To overcome this, genetic transformation can be used for the modifi cation of trait-related genes in few plants.Flower colour, fl ower fragrance, dwarfi sm and increase in vase life of climbing ornamentals are some of the important areas of research which contribute to the market value of any ornamental plant. In last few decades, the relationship between fl avonoid biosynthetic pathway and anthocyanin production has been well studied, and genetic engineering is being used to produce cultivars with novel pigmentation in fl owers by modifi cation in the biosynthesis of fl avonoid/anthocyanin. Initially, blue rose was developed by introducing genes for delphinidin pigments to ordinary roses. But recently, gene silencing using RNAi technology is being used to prevent red pigment formation and allow the production of blue pigment. Colour intensity and fl ower longevity can be increased by the transformation and modulation of genes that encode for pigment and ethylene biosynthetic pathways. However, with the knowledge of genes related to fragrance biosynthesis, one can improve the ornamental climbers, such as Quisqualis indica ,

Plants by nature protect themselves by producing secondary metabolites which often have pronounced bioactivities. The presence of these metabolites is responsible for the active interaction of plants with their environment defending themselves against a variety of herbivores and pathogenic microorganisms as well as various kinds of abiotic stresses. Climber plants contain large number of useful secondary metabolites. Besides their pharmacological role, secondary metabolites also contain some other properties. Artabotrys hexapetalus , a climbing herb, secretes oil which is used in perfume industry. Capparis zeylanica is a thorny stout climbing shrub, used in the treatment of snake bite and to cure small pox, cholera, etc. Stem barks and roots of Tinospora cordifolia , a woody climber, are used in dysentery and diarrhoea. Toddalia asiatica , an evergreen climber, produced nitidine secondary metabolite which contains anti-HIV and antimalarial and anticancerous properties, but its production is not enough for commercial supply. Tissue culture technology has emerged as a supplementary branch to fulfi l demands for this valuable secondary metabolite. Various in vitro methods for enhancement of secondary metabolites are available such as hairy root culture, treatment of elicitors and use of precursors and introduction of any foreign gene via bacterial transformation.Current progresses have been made in the fi eld of molecular biology through the alteration in metabolic skeleton of plant secondary metabolism. With the use of various genes (involved in the synthesis of enzymes and their regulatory proteins), diverse pathways have been traced and being transformed. Antisense technology has been emerged as an additional alternative for enhancement of secondary metabolites. In Tylophora indica enhancement in kaempferol, an antioxidant compound was observed by using precursors like salicylic acid, ornithine, cinnamic acid, tyrosine and phenylalanine. The total dry weight of 2-hydroxy-4-methoxy benzaldehyde was enhanced in hairy root cultures of Decalepis hamiltonii . The present chapter provides an insight on the use of biotechnological techniques for the enhancement of secondary metabolites in medicinal climbers.

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