Hassan Jaleel

Effect of polyacrylamide soil-dressing on physiological attributes, essential oil content, and composition of vetiver (Vetiveria zizanioides)

ABSTRACT A pot experiment was conducted on vetiver (Vetiveria zizanioides) in a completely randomized design to study the effect of soil-dressing with polyacrylamide (PAM) on the quality and quantity of vetiver essential oil (EO). Among the PAM doses tested, 120 mg kg−1 increased 17.3% and 39.6% in the EO content and yield, respectively. Gas chromatography (GC) revealed that khusimol content and yield was increased by 26.7% and 77.0% over the respective control. The study suggests that PAM increased the root biomass by improving soil environment thus increasing the growth parameters, physiological attributes, and EO production.

Signaling Pathways of Anticancer Plants: Action and Reaction

Insights into the alterations of the mammalian genome in neoplastic diseases and the mechanism of action of the therapeutic anticancer drugs are one of the extremely important, diverse, and challenging areas of study currently. By the virtue of lingering toxicity of the reputable chemical drugs, plant-derived anticancer substances, viz., vinblastine, vincristine, Taxol, topotecan, camptothecin, and podophyllotoxin derivatives, are highly safe and efficient in the treatment and management of this monstrous disease. Among the list of accessible targets of the therapeutic drugs, DNA replication and mitosis, hormonal regulation of cell growth, aberrant signaling pathways, cell surface receptors, and second messengers are noteworthy. Nowadays, newer therapeutic approaches are being followed, and an increased understanding into the mechanism of action of the therapeutic anticancer agents is evolving due to continuous and relentless efforts of the researchers. The aim of the present chapter is to highlight the application of medicinal plants and their secondary metabolites as anticancer substances and also focus on the signaling aspects of potential anticancer compounds to find out their mechanisms of action against cancer cells.

Unraveling the Cumulative Effect of Soil-Applied Radiation-Processed Sodium Alginate and Polyacrylamide on Growth Attributes, Physiological Activities, and Alkaloids Production in Periwinkle [Catharanthus roseus (L.) G. Don]

Cancer has taken millions of lives in the passing decade alarming the scientists to urgently design the magic bullets for this jeopardy. Catharanthus roseus (L.) G. Don reportedly emerged as a remedy to this problem contributing, medicinal system, two of its paramount anticancer alkaloid constituents, vincristine and vinblastine. Recently, a new agro-technique has been evolved in which gamma-irradiated natural polysaccharides (e.g., alginate, carrageenan, and chitosan) are degraded into oligomers. When these oligomers are applied through foliar application to the plants, it proves as potent plant promoter. On the other hand, for quality soil structure, polyacrylamide (PAM) is used whose application to the soil contributes a great deal in terms of stability to soil and increased water holding capacity. A pot experiment was conducted to study the effect of soil-applied polyacrylamide (PAM) and irradiated sodium alginate (ISA) alone or in combination on C. roseus. The plants were harvested at 90 days after transplanting (DAP). Of the six treatments [(i) water sprayed control (Treatment 1), (ii) un-irradiated sodium alginate (UISA) (Treatment 2), (iii) irradiated sodium alginate (ISA) (Treatment 3), (iv) PAM (Treatment 4), (v) UISA + PAM (Treatment 5), and (vi) ISA + PAM (Treatment 6)] increased the values of most of the parameters significantly including fresh and dry weights of plants, contents of nitrogen, phosphorus and potassium, chlorophyll and carotenoids content, and activities of carbonic anhydrase and nitrate reductase in the leaves. The combined application of ISA + PAM also increased total content and yield of leaf alkaloid by 14.1% and by 40.2% over the respective controls. Conclusively, the technique seems economically and ergonomically successful in increasing the expensive alkaloid production of C. roseus.

Essential Oil and Citral Production in Field-Grown Lemongrass in Response to Gamma-Irradiated Chitosan

ABSTRACT A field trial was conducted to study the effect of foliar application (0, 40, 60, 80, and 100 mg.L–1) of irradiated chitosan (ICH) on the growth characteristics, biochemical parameters, and yield and quality attributes of lemongrass (Cymbopogon flexuosus). The lemongrass essential oil (EO) was extracted using Clevenger-type apparatus and analyzed using gas chromatography (GC). ICH at 80 mg.L–1 increased the carbonic anhydrase activity (21.5%), nitrate reductase activity (17.4%), and chlorophyll fluorescence (14.6%); it also increased the content and yield of EO by 36.7% and 98.0%, respectively, and the citral content by 13.5%.

Elucidating the dynamics of physiology and essential oil production in lemongrass using alginate oligomers under field conditions

Cymbopogon flexuosus (Steud.) Wats. (lemongrass) essential oil (EO) is valued for its aromatic and medicinal properties as it holds an important share among volatile oils traded worldwide and exhibits massive diversity in commercial and consumer utility. The last decade witnessed several pot experiments to test the ability of radiation-processed sodium alginate as a plant growth elicitor. Therefore, the present work was designed to authenticate the pot experiment findings and the study was carried out in the field (30 × 30 m2), according to the simple randomised block design at Agricultural Farm, Aligarh Muslim University, Aligarh, UP (India). Different foliar concentrations of irradiated sodium alginate (ISA; 0 (control), 40, 60, 80 and 100 mg L–1) were applied to scrutinise the performance of lemongrass with regard to ISA under field conditions. The effect of ISA, at a given concentration range of 40–100 mg L–1, was found significant in terms of growth, physiological and biochemical as well as quality attributes. However, ISA-60 mg L–1 proved most favourable and substantially enhanced the activities of carbonic anhydrase and nitrate reductase by 18.4 and 15.1%, respectively and chlorophyll fluorescence by 12.8% in comparison to control. Further, due to applied treatment, the content and yield of EO was increased by 35.6 and 91.4%, respectively, over control. Moreover, citral yield was also enriched by 90.4% over control due to ISA applied at 60 mg L–1.

Structural re-arrangement of depolymerized sodium alginate enriches peltate glandular trichomes and essential oil production of spearmint

Over the past decade, radiation-degraded polysaccharides have been used as regulators of growth and development in several crop plants. In quest of the possible reasons of previously established growth-promotion activity of irradiated sodium alginate (ISA), structural parameters of irradiated and un-irradiated sodium alginate were analysed using Ultraviolet-visible spectroscopy (UV-vis) and Fourier Transform Infrared spectroscopic (FT-IR) studies to develop an understanding of structure-property relationship. Using foliar application, response to graded concentrations of ISA was tested in terms of yield and quality attributes of spearmint (Mentha spicata L.). Among different concentrations of ISA [0 (control), 40, 80, 120 and 160mgL-1], 80mgL-1 proved to be the optimum foliar-spray treatment for most of the parameters studied including peltate glandular-trichomes density, which was increased from 20 to 44mm-2. Measurements made at 150days after planting revealed that foliar application of ISA at 80mgL-1 increased the content and yield of spearmint essential oil (EO) by 36.0 and 122.6%, respectively, in comparison to the control. Compared to the control, gas chromatography mass spectrometry (GC-MS) analysis revealed an increase of 18.7% in the carvone content and a decrease of 15.7% in limonene content of the spearmint EO.