Chloroplast genome transformation of medicinal plant Artemisia annua

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Organic and inorganic fertilizers influence biomass production and esculin content in Cichorium intybus L.

Cichorium intybus L. is a promising and potent industrial medicinal herb but the relatively low content of esculin and unavailability of mass scale propagation protocol are major impediments for the commercial production of the drug. The enhancement in the yield of esculin is hence, highly desirable, which can be achieved by adequate and judicious supply of plants nutrients or by adopting more expensive and complex protocol of biotechnology. The field experiment was designed in random plots to study the effect of organic manure (20 tonnes ha-1) and chemical fertilizers (N240, P120, K100, S80, kg ha−1; Nitrogen, Phosphorus, Potassium and Sulphur, respectively) on the accumulation of esculin and biomass in various plant parts through the various developmental stages, rosette, bolting, pre-flowering, flowering and post-flowering of C. intybus. Esculin yield from dried leaves increased significantly at flowering stage in the plants treated with N80+100+60 + P120 + K100 +   S 20+40+20 (31.71% and 111.22 %) when compared with control. Yield of dry leaf biomass ranged between 628.15 to 986.07 kg ha−1 at flowering stage in various treatments

Lead-induced oxidative stress and metabolic alterations in Cassia angustifolia Vahl

Forty-five-days old plants of Indian senna (Cassia angustifolia Vahl.) were subjected to 0–500 µM lead acetate (Pb-Ac) in pot culture. Changes in contents of thiobarbituric acid reactive substances (TBARS), ascorbate, glutathione, proline, sennosides (a+b), and activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), and catalase (CAT) were studied at pre-flowering (60 d after sawing, DAS), flowering (90 DAS) and post-flowering (120 DAS) stages of plant development. Compared with the controls, the Pb-Ac treated plants showed an increase in contents of TBARS, dehydroascorbate, oxidized and total glutathione at all stages of growth. However, sennoside yield and contents of ascorbate and reduced form of glutathione declined. Proline content increased at 60 DAS but declined thereafter. Activities of SOD, APX, GR and CAT were markedly increased. Sennoside content was higher at 60 and 90 DAS but lower at 120 DAS, compared to the control

Enhancement of diterpenoid steviol glycosides by co-overexpressing SrKO and SrUGT76G1 genes in Stevia rebaudiana Bertoni.

Stevia rebaudiana (stevia) contains commercially important steviol glycosides, stevioside and rebaudioside A, these compounds have insulinotropic and anti-hyperglycemic effect. Steviol, stevioside and rebaudioside-A have taste modulation and insulin potentiation activity. Stevia leaves are composed of steviol (2-5%), stevioside (4-13%) and rebaudioside-A (1-6%). Stevioside has after-taste bitterness, rebaudioside-A is sweetest in taste among all the glycosides present. Therefore, lower ratio of rebaudioside-A to stevioside has bitter after-taste, which makes stevia plants unpalatable. By over-expressing the genes, SrUGT76G1 and SrKO, we propose to increase the ratio of RebA to stevioside in stevia. Various lines were generated and amongst them, seven lines had both the transgenes present. Co-overxpresion of SrUGT76G1 and SrKO led to the increased concentration of RebA in all the seven transgenic lines (KU1-KU7) than control plant and RebA to stevioside ratio also increased significantly. Steviol, stevioside and RebA showed a differential concentration in all the seven lines, but the pattern was the same in all of them and the ratio of RebA to stevioside increased dramatically. In transgenic line 2 (KU2), RebA showed a steep increase in concentration 52% the rebaudioside-A to stevioside ratio increased from 0.74 (control) to 2.83. In overall all the lines, RebA showed a positive correlation with steviol and stevioside. Overexpression of SrKO led to an increase in steviol which increased the stevioside, overexpression of SrUGT76G1 ultimately increased RebA concentration. In conclusion, concentration of RebA increased significantly with co- overexpression of SrUGT6G1 and SrKO genes. Lines with increased RebA are more palatable and commercially viable

Phycoremediation of municipal wastewater by microalgae to produce biofuel

Municipal wastewater (WW), if not properly remediated, poses a threat to the environment and human health by carrying significant loads of nutrients and pathogens. These contaminants pollute rivers, lakes and natural reservoirs where they cause eutrophication and pathogen-mediated diseases. However, the high nutrient content of WW makes it an ideal environment for remediation with microalgae that require high nutrient concentrations for growth and are not susceptible to toxins and pathogens. Given that an appropriate algal strain is used for remediation, the incurred biomass can be refined for the production of biofuel. Four microalgal species (Chlamydomonas reinhardtii, Chlorella sp., Parachlorella kessleri-I and Nannochloropsis gaditana) were screened for efficient phycoremediation of municipal WW and potential use for biodiesel production. Among the four strains tested, P. kessleri-I showed the highest growth rate and biomass production in 100% WW. It efficiently removed all major nutrients with a removal rate of up to 98% for phosphate after ten days of growth in 100% municipal WW collected from Delhi. The growth of P. kessleri-I in WW resulted in a 50% increase of biomass and a 115% increase of lipid content in comparison to growth in control media. The FAME and fuel properties of lipids isolated from cells grown in WW complied with international standards. The present study provides evidence that the green alga P. kessleri-I effectively remediates municipal WW and can be used to produce biodiesel

Overexpression of tobacco osmotin gene leads to salt stress tolerance in strawberry (Fragaria × ananassa Duch.) plants

465-471Transgenic plants of strawberry tolerant to salt stress were produced using Agrobacterium mediated gene transfer technology. Leaf discs of in vitro grown plantlets of strawberry cv. Chandler were used as explants. Agrobacterium tumefaciens strain GV2260 harbouring osmotin gene under the control of CaMV 35S promoter in a binary vector system pBinAR was used in transformation experiments. Transgene integration and copy number were assessed by PCR and Southern hybridization confirming single copy as well as multiple copies of transgene integration in 10 different lines of transgenic strawberry. Expression of osmotin gene was confirmed in transgenic lines TL3, TL5, TL9 using Northern hybridization, while biochemical analysis revealed enhanced levels of proline, total soluble protein and chlorophyll content as compared to the wild plants. Leaf disc assays performed using both wild-type and transgenic plants had shown that these transgenic lines were tolerant to salt stress

Standardization and estimation of nitrate reductase activity in the leaves of Ammi majus L. (Bishops weed) in relation to sulphur deficiency and seed yield

Field experiments were conducted to determine the interactive effect of sulphur (S) and nitrogen (N) in relation to nitrate reductase activity as the enzyme catalyze rate-limiting step of the assimilatory pathways of nitrate and sulphate, and seed yield of Ammi majus L. (commonly called as atrilal). To carry out this study we cultivated atrilal in experimental field and used two combinations of sulphur (S) and nitrogen (N) nutrient (-S+N & +S+N in kg ha-1) along with control group (without S & N) in soil during sowing. Sulphur & nitrogen nutrients were applied into field as single basal dose. To the best of our knowledge, no report has been published so far to get the reliable protocol for NR activity in terms of medicinal plant productivity and quality; hence, we standardized the NR activity in leaves prior its estimation in the experimental materials. Results show that sulphur application significantly enhanced the nitrate reductase activity (NR) in fresh leaves of atrilal as well as seed yield (P\u3c0.05) when compared with the sulphur deficient (-S+N) and control group. Internal CO2 concentration and stomatal conductance were also high in the leaves of Atrilal at different growth stages and this increase may be correlated with increased photosynthesis rate and higher NR activity in the leaves of plants grown with combined application of S and N when compared with N alone. The results obtained in this study suggested that sulphur is involved along with nitrogen in regulation of enhanced NR activity and physiological changes which results higher seed yield