Optimization of Elicitation Conditions with Methyl Jasmonate and Salicylic Acid to Improve the Productivity of Withanolides in the Adventitious Root Culture of Withania somnifera (L.) Dunal

Adventitious root cultures derived from leaf derived callus of Withania somnifera (L.) Dunal were treated with methyl jasmonate and salicylic acid independently. Biomass accumulation, culture age, elicitation period, and culture duration were optimized for higher withanolides production in the two best-responding varieties collected from Kolli hills (Eastern Ghats) and Cumbum (Western Ghats) of Tamil Nadu, India. Between the two elicitors, salicylic acid (SA) improved the production of major withanolides (withanolide A, withanolide B, withaferin A, and withanone) as well as minor constituents (12-deoxy withastramonolide, withanoside V, and withanoside IV) in the Kolli hills variety. Treatment of root biomass (11.70?g FW) on 30-day-old adventitious root cultures with 150???M SA for 4?h elicitor exposure period resulted in the production of 64.65?mg?g^?l dry weight (DW) withanolide A (48-fold), 33.74?mg?g^?l DW withanolide B (29-fold), 17.47?mg?g^?l DW withaferin A (20-fold), 42.88?mg?g^?l DW withanone (37-fold), 5.34?mg?g^?l DW 12-deoxy withastramonolide (nine fold), 7.23?mg?g^?l DW withanoside V (seven fold), and 9.45?mg?g^?l DW withanoside IV (nine fold) after 10?days of elicitation (40th day of culture) when compared to untreated cultures. This is the first report on the use of elicitation strategy on the significant improvement in withanolides production in the adventitious root cultures of W. somnifera.     

Biochemical alternation and silicon accumulation in groundnut (Arachis hypogaea L.) in response to root and foliar application of two sources of silicon

Abstract

Silica deposits in leaves of groundnut ranged from 3.23 to 6.16% and 2.61 to 6.52% when sodium meta silicate was applied as foliar spray at the rate of 0.5, 1.0, 2.0, 3.5 and 5.0%, and soil application at the rate of 5.0, 7.5, 10.0, 15 and 20% and 4.44 to 11.94% and 3.57 to 9.33% when calcium silicate was applied through leaves and soil at the same doses, respectively in contrast to 2.0% in plants without silica fertilizer applications. Similarly, polyphenol oxidase (PPO) activity was highest (43.26 units) in plant system, in case of foliar spray of calcium silicate at the rate of 5.0% and 33.80 units with reference to foliar spray of meta silicate at the rate of 5.0% whereas it was only 19.10 units in untreated check. Among the two sources of silica fertilizers tested, foliar spray of calcium silicate at 5.0% was effective in facilitating the maximum deposition of silica content apart from increasing the activities of PPO in groundnut leaves.