[Show abstract][Hide abstract] ABSTRACT: Callus cultures were initiated from leaf explants of Artemisia annua L. plants for artemisinin production using Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of plant growth regulators (PGRs), viz., BAP, NAA, 2,4-D and TDZ. The combination of all PGRs at different concentrations showed a better response in induction of undifferentiated friable calli in the light phase as compared to the dark phase. The calli of transgenic plants over-expressing hmgr gene yielded a biomass of 0.13 g dw/explant in the light in comparison to 0.06 g dw/explant in the dark, when grown on MS medium supplemented with BAP (1.0 mg L-1) and NAA (2.0 mg L-1). The non-transgenic (untransformed plant) calli, however, yielded a biomass of 0.10 g dw/explant in the light when grown on MS medium supplemented with the same concentrations of BAP and NAA, while yield was 0.06 g dw/explant in the dark in MS medium
supplemented with BAP (1.0 mg L-1) and 2, 4-D (1.0 mg L-1). Further, the maximum artemisinin content (0.006% on dw basis) was recorded in both transgenic and non-transgenic calli that were grown on MS medium supplemented with BAP (1.0 mg L-1) and NAA (2.0 mg L-1) under light phase.
Full-text · Article · Jan 2014 · Indian Journal of Biotechnology
[Show abstract][Hide abstract] ABSTRACT: Leaf explants were used frequently as target tissue to generate transgenic of Artemisia. annua L. However, obtaining a large number of transgenic lines through out the year is a laborious and delicate process. To circumvent this, we have developed a highly efficient leaf explant based Agrobacterium mediated transformation of A. annua L. plant. The gus gene was used as screenable marker to assess and optimize the performance of T-DNA delivery. The age of explant, kind of bacterial inoculation, suspension duration, infection times and co-culture conditions were optimized. The co-culture was carried out with Agrobacterium tumefaciens strain EHA105 under desiccation condition in the dark at 25-28 0C for 2-4 days. Complete analysis of transgene insertion demonstrated that the optimized method of transformation from leaf explants of A. annua L. was efficient and highly reproducible.
[Show abstract][Hide abstract] ABSTRACT: Podophyllotoxin, a well-known naturally occurring aryl tetralin lignan produced by few plant species is used as precursor for the chemical synthesis of the anticancer drugs like etoposide, teniposide and etopophos phosphate. The availability of this lignan is limited due to the scarce occurrence of its natural sources. Further, synthetic approaches for its production are still commercially unacceptable. This paper reports the synthesis of podophyllotoxin by an endophytic fungus Fusarium solani isolated from the roots of Podophyllum hexandrum. The presence of podophyllotoxin in fungal biomass was confirmed and quantified by HPLC and mass spectrometry. The fungus is able to produce 29.0 µg/g podophyllotoxin on dry weight basis.
Full-text · Article · Mar 2012 · African journal of microbiology research
[Show abstract][Hide abstract] ABSTRACT: In this report, rapid and effective shoot as well as root regeneration system through direct multiplication was successfully developed for Cichorium intybus L. Furthermore, the effect of exogenous growth regulators (TDZ and IAA) at different concentrations on the regulation process of the plant was also studied. Enhanced production of esculin in developed C. intybus L. was evaluated using leaf extract. Only on the expense of 20 days, regeneration was seen and very low dose of TDZ was seen to be more effective. When 0.02 mg/L of TDZ was combined with 1.5mg/L of IAA, nearly 100% of explants produced shoots with the highest number of regenerated shoots (85.37). With further increase in concentration (≥ 0.05 mg/L), the number of shoots per explants get decreased. A lower NAA to IBA ratio (1.0mg/L of IBA and 0.5mg/L of NAA) seemed to be more effective for root generation and considered to be the most effective combination among the tried groups. IBA was more effective in root development than NAA, but both were comparatively effective. On quantitative analysis by RP-HPLC, the 76.23% of Esculin were found in leaf extract of the in vitro developed C. intybus L. This amount was 26.77% higher than normal grown plants.
[Show abstract][Hide abstract] ABSTRACT: A high frequency somatic embryogenesis has been established in mustard crop (Brassica juncea L. cv. Pusa Jai kisan), in which embryogenic calli were induced from hypocotyls and cotyledons of in vitro germinated seedlings. The hypocotyl derived embryogenic calli (HEC) were transparent and whitish, while cotyledon derived embryogenic calli (CEC) were creamy yellow in colour. Highest embryogenic callusing frequency (98%) was obtained in cotyledons on 2 mg/l 2, 4-D added MS medium. Hypocotyls and cotyledons derived calli were differentiated into somatic embryos at high frequency (90-100%) on 2 mg/l 2ip or 2 mg/l BAP amended medium. Embryo maturation occurred on the same embryo development medium, and germination was best achieved on 2.6 mg/l ABA amended medium. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and histological studies revealed that the embryos had bipolar structure and developed mainly from the epidermis of explants. Furthermore, the embryonic tissues have stored bodies and numerous cell organelles. Various embryological stages are presented in this short communication. This protocol is much faster and took just six weeks to obtain complete plantlets. Abbreviations: BAP-6-benzylaminopurine, 2,4-D-2,4-dichlorophenoxyacetic acid, TDZ-thidizouron, 2ip-2-isopentenyladenine, SEM-scanning electron microscopy, Kin-Kinetin, TEM-transmission electron microscopy, ABA-abscisic acid, HEC-hypocotyl derived embryogenic calli, CEC-cotyledon derived embryogenic calli, DMRT-Duncan multiple range test, PGR-plant growth regulator, ANOVA-analysis of variance, MS-Murashige and Skoog's (1962) medium, SE-somatic embryogenesis.
Full-text · Article · Dec 2011 · Australian Journal of Crop Science