Phytoremediation ability and selected genetic transcription in Hydrocotyle umbellata-under cadmium stress.

Cadmium (Cd) is the most toxic element which may cause serious consequences to microbial communities, animals, and plants. The use of green technologies like phytoremediation employs plants with high biomass and metal tolerance to extract toxic metals from their rooting zones. In the present work, Hydrocotyle umbellata was exposed to five Cd concentrations (2, 4, 6, 8, and 10 µmol) in triplicates to judge its phytoextraction ability. Effects of metal exposure on chlorophyll (Chl), bio-concentration factor (BCF), translocation factor (TF), and electrolyte leakage (EL) were analyzed after 10 days of treatment. Metal-responding genes were also observed through transcriptomic analysis. Roots were the primary organs for cadmium accumulation followed by stolon and leaves. There was an increase in EL. Plants showed various symptoms under increasing metal stress namely, chlorosis, browning of the leaf margins, burn-like areas on the leaves, and stunted growth, suggesting a positive relationship between EL, and programmed cell death (PCD). Metal-responsive genes, including glutathione, expansin, and cystatin were equally expressed. The phytoextraction capacity and adaptability of H. umbellata L. against Cd metal stress was also demonstrated by BCF more than 1 and TF less than 1.

The results of the current study demonstrated that Hydrocotyle umbellata is a good choice for environmental cleanup in areas with mild Cd contamination. According to TF and BCF, the plant demonstrated a considerable uptake of Cd. Additionally, H. umbellata's eligibility as a phytoremediation agent for Cd was supported by the transcription of numerous metal-responsive genes, including glutathione, expansin, cystatin, and other genes associated with growth.

Exogenously applied nicotinic acid alleviates drought stress by enhancing morpho-physiological traits and antioxidant defense mechanisms in wheat.

Across the globe, the frequent occurrence of drought spells has significantly undermined the sustainability of modern high-input farming systems, particularly those focused on staple crops like wheat. To ameliorate the deleterious impacts of drought through a biologically viable and eco-friendly approach, a study was designed to explore the effect of nicotinic acid on different metabolic, and biochemical processes, growth and yield of wheat under optimal moisture and drought stress (DS). The current study was comprised of different levels of nicotinic acid applied as foliar spray (0 g L-1, 0.7368, 1.477, 2.2159 g L-1) and fertigation (0.4924, 0.9848, and 1.4773 g L-1) under normal conditions and imposed drought by withholding water at anthesis stage. The response variables were morphological traits such as roots and shoots characteristics, yield attributes, grain and biological yields along with biosynthesis of antioxidants. The results revealed that nicotinic acid dose of 2.2159 g L-1 out-performed rest of treatments under both normal and DS. The same treatment resulted in the maximum root growth (length, fresh and dry weights, surface area, diameter) and shoot traits (length, fresh and dry weights) growth. Additionally, foliar applied nicotinic acid (2.2159 g L-1) also produced as the highest spike length, grains spike-1, spikelet's spike-1 and weight of 1000 grains. Moreover, these better yield attributes led to significantly higher grain yield and biological productivity of wheat. Likewise in terms of physiological growth of wheat under DS, the same treatment remained superior by recording the highest SPAD value, relative water content, water potential of leaves, leaf area, stomatal conductance (292 mmolm-2S-1), internal carbon dioxide concentration, photosynthesis and transpiration rate. Interestingly, exogenously applied nicotinic acid remained effective in triggering the antioxidant system of wheat by recording significantly higher catalase, peroxidase, superoxide dismutase and ascorbate peroxidase.

Comparative analysis of phyto-fabricated chitosan, copper oxide, and chitosan-based CuO nanoparticles: antibacterial potential against Acinetobacter baumannii isolates and anticancer activity against HepG2 cell lines.

The aim of this study was to provide a comparative analysis of chitosan (CH), copper oxide (CuO), and chitosan-based copper oxide (CH-CuO) nanoparticles for their application in the healthcare sector. The nanoparticles were synthesized by a green approach using the extract of Trianthema portulacastrum. The synthesized nanoparticles were characterized using different techniques, such as the synthesis of the particles, which was confirmed by UV-visible spectrometry that showed absorbance at 300 nm, 255 nm, and 275 nm for the CH, CuO, and CH-CuO nanoparticles, respectively. The spherical morphology of the nanoparticles and the presence of active functional groups was validated by SEM, TEM, and FTIR analysis. The crystalline nature of the particles was verified by XRD spectrum, and the average crystallite sizes of 33.54 nm, 20.13 nm, and 24.14 nm were obtained, respectively. The characterized nanoparticles were evaluated for their in vitro antibacterial and antibiofilm potential against Acinetobacter baumannii isolates, where potent activities were exhibited by the nanoparticles. The bioassay for antioxidant activity also confirmed DPPH scavenging activity for all the nanoparticles. This study also evaluated anticancer activities of the CH, CuO, and CH-CuO nanoparticles against HepG2 cell lines, where maximum inhibitions of 54, 75, and 84% were recorded, respectively. The anticancer activity was also confirmed by phase contrast microscopy, where the treated cells exhibited deformed morphologies. This study demonstrates the potential of the CH-CuO nanoparticle as an effective antibacterial agent, having with its antibiofilm activity, and in cancer treatment.

Biofortification efficiency with magnesium salts on the increase of bioactive compounds and antioxidant capacity in snap beans / Eficiência da biofortificação com sais de magnésio no aumento de compostos bioativos e capacidade antioxidante em feijão-vagem

ABSTRACT: Biofortification of food crops is implemented through the application of mineral fertilizers, to improve the levels of essential mineral elements for human nutrition. Magnesium is a key macronutrient in crop production and quality; however, worldwide, it is the most limiting macronutrient in agriculture. Magnesium plays an important role in manipulating physiological and biochemical processes in plants. Therefore, the objective of this study was to evaluate the efficacy of biofortification with magnesium chloride and sulfate on the accumulation of bioactive compounds and antioxidant capacity in snap bean cv. Strike. Two sources of Magnesium were applied via edaphic route: Magnesium chloride and magnesium sulfate at doses of 0, 50, 100 and 200 ppm during 2018 in Mexico. Accumulation of bioactive compounds (total phenols, total flavonoids and total anthocyanins) and antioxidant capacity in snap bean fruits were evaluated. Results obtained indicate that the concentration of total flavonoids, total anthocyanins and antioxidant capacity in the edible parts of snap beans were higher in the MgSO4 treatment than in the MgCl2 treatments, exceeding 30, 59 and 6% respectively. This is one of the first studies on the edaphic agronomic biofortification of Mg+ and its effect on nutraceutical quality in snap bean. An interesting result is that MgSO4 produced high concentrations of anthocyanins in edible snap beans. These results can be applied as a new strategy to reduce malnutrition and improve the health of the population in poor urban and rural communities in developing countries.

RESUMO: A biofortificação de culturas alimentares é implementada através da aplicação de fertilizantes minerais, para melhorar os níveis de elementos minerais essenciais para a nutrição humana. O magnésio é um macronutriente essencial na produção e qualidade das culturas, no entanto, em todo o mundo, é o macronutriente mais limitante da agricultura. O magnésio desempenha um papel importante na manipulação de processos fisiológicos e bioquímicos nas plantas. Portanto, o objetivo deste estudo foi avaliar a eficácia da biofortificação com cloreto e sulfato de magnésio no acúmulo de compostos bioativos e capacidade antioxidante em feijões verdes cv. Strike. Duas fontes de magnésio foram aplicadas por via edáfica: cloreto de magnésio e sulfato de magnésio nas doses de 0, 50, 100 e 200 ppm durante o ano de 2018 no México. Foram avaliados o acúmulo de compostos bioativos (fenóis totais, flavonóides totais e antocianinas totais) e a capacidade antioxidante em frutos de feijão-vagem. Os resultados obtidos indicam que a concentração de flavonoides totais, antocianinas totais e capacidade antioxidante nas partes comestíveis do feijão-vagem foram maiores no tratamento com MgSO4 do que nos tratamentos com MgCl2, ultrapassando 30, 59 e 6% respectivamente. Este é um dos primeiros estudos sobre a biofortificação agronômica edáfica do Mg+ e seu efeito na qualidade nutracêutica do feijão-vagem. Um resultado interessante é que o MgSO4 produziu altas concentrações de antocianinas no feijão-vagem comestível. Esses resultados podem ser aplicados como uma nova estratégia para reduzir a desnutrição e melhorar a saúde da população em comunidades urbanas e rurais pobres em países em desenvolvimento.

Enterobacter cloacae, an Emerging Plant-Pathogenic Bacterium Affecting Chili Pepper Seedlings.

A previously unreported bacterial disease on chili pepper (Capsicum annuum L.) seedlings affecting as many as 4% of seedlings was observed in greenhouses in Chihuahua, Mexico (Delicias and Meoqui counties). Initial lesions appeared as irregular small spots on leaves and brown necrosis at margins tips were observed. Later, the spots became necrotic with a chlorotic halo. Advanced disease was associated with defoliation. A Gram negative, rod-shaped bacterium was isolated from diseased chili pepper seedlings. Three inoculation methods revealed that isolated strains produce foliage symptoms, similar to those observed in naturally infected seedlings. Pathogenic strains that caused symptoms in inoculated seedlings were re-isolated and identified to fulfill koch's postulate. Polyphasic approaches for identification including biochemical assays (API 20E and 50CH), carbon source utilization profiling (Biolog) and 16S rDNA, hsp60 and rpoB sequence analysis were done. Enterobacter cloacae was identified as the causal agent of this outbreak on chili pepper seedlings.