Inoculation of heavy metal resistant bacteria alleviated heavy metal-induced oxidative stress biomarkers in spinach (Spinacia oleracea L.).

Most vegetable crops are severely affected by the uptake of heavy metals from the soil. Heavy metals in vegetable bodies generate reactive oxygen species (ROS) that unbalance the antioxidant defense system. This study was initiated to determine the physiological and biochemical characteristics of spinach plants grown on soil contaminated with heavy metals and responding to Bacillus cereus and Bacillus aerius were isolated from soil contaminated with heavy metals. Heavy metal contamination led to a significant reduction in seed germination, seedling biomass, protein, and total nitrogen content of spinach plants grown in contaminated soils compared to control soils. In contrast, a significant increase in the content of metallothioneins and antioxidant enzymes was observed. Plants inoculated with B. cereus and B. aerius significantly reduced the oxidative stress induced by heavy metals by improving seed germination (%), seedling growth, nitrogen, and protein content. The content of metallothioneins and the activities of antioxidant enzymes were reduced in spinach plants grown from seeds inoculated with bacterial strains. In addition, plants inoculated with, B. cereus and B. aerius showed greater stomata opening than plants grown on soil contaminated with heavy metals, whose stomata were almost closed. These results suggested that both bacterial strains enhanced plant growth by reducing oxidative stress caused by metals.

Mitigation effect of alpha-tocopherol and thermo-priming in Brassica napus L. under induced mercuric chloride stress.

Soil pollution with heavy metals has grown to be a big hassle, leading to the loss in farming production particularly in developing countries like Pakistan, where no proper channel is present for irrigation and extraction of these toxic heavy metals. The present study aims to ameliorate the damages caused by heavy metal ions (Hg-Mercury) on rapeseed (Brassica napus L.) via a growth regulator (α-tocopherol 150 mg/L) and thermopriming technique at 4 °C and 50 °C to maintain plant agronomical and physiological characteristics. In pot experiments, we designed total of 11 treatments viz.( T0 (control), T1 (Hg4ppm), T2 (Hg8ppm), T3 (Hg4ppm + 4 °C), T4 (Hg4ppm + 4 °C + tocopherol (150 m/L)), T5 (Hg4ppm + 50 °C), T6 (Hg4ppm + 50 °C + tocopherol (150 mg/L)), T7 (Hg8ppm + 4 °C), T8 (Hg8ppm + 4 °C + tocopherol (150 mg/L)), T9 (Hg8ppm + 50 °C), T10 (Hg8ppm + 50 °C + tocopherol (150 mg/L) the results revealed that chlorophyll content at p < 0.05 with growth regulator and antioxidant enzymes such as catalase, peroxidase, and malondialdehyde enhanced up to the maximum level at T5 = Hg4ppm + 50 °C (50 °C thermopriming under 4 ppm mercuric chloride stress), suggesting that high temperature initiate the antioxidant system to reduce photosystem damage. However, protein, proline, superoxide dismutase at p < 0.05, and carotenoid, soluble sugar, and ascorbate peroxidase were increased non-significantly (p > 0.05) 50 °C thermopriming under 8 ppm high mercuric chloride stress (T9 = Hg8ppm + 50 °C) representing the tolerance of selected specie by synthesizing osmolytes to resist oxidation mechanism. Furthermore, reduction in % MC (moisture content) is easily improved with foliar application of α-tocopherol and 50 °C thermopriming and 4 ppm heavy metal stress at T6 = Hg4ppm + 50 °C + α-tocopherol (150 mg/L), with a remarkable increase in plant vigor and germination energy. It has resulted that the inhibitory effect of only lower concentration (4 ppm) of heavy metal stress was ameliorated by exogenous application of α-tocopherol and thermopriming technique by synthesizing high levels of proline and antioxidant activities in maintaining seedling growth and development on heavy metal contaminated soil.

Breeding for water-use efficiency in wheat: progress, challenges and prospects.

Drought poses a significant challenge to wheat production globally, leading to substantial yield losses and affecting various agronomic and physiological traits. The genetic route offers potential solutions to improve water-use efficiency (WUE) in wheat and mitigate the negative impacts of drought stress. Breeding for drought tolerance involves selecting desirable plants such as efficient water usage, deep root systems, delayed senescence, and late wilting point. Biomarkers, automated and high-throughput techniques, and QTL genes are crucial in enhancing breeding strategies and developing wheat varieties with improved resilience to water scarcity. Moreover, the role of root system architecture (RSA) in water-use efficiency is vital, as roots play a key role in nutrient and water uptake. Genetic engineering techniques offer promising avenues to introduce desirable RSA traits in wheat to enhance drought tolerance. These technologies enable targeted modifications in DNA sequences, facilitating the development of drought-tolerant wheat germplasm. The article highlighted the techniques that could play a role in mitigating drought stress in wheat.

Temporal Trends and Burden of Rheumatic Heart Disease in South Asia: A Comprehensive Analysis of Three Decades from Global Burden of Disease Study.

Background: The objective of this study is to conduct a temporal analysis of rheumatic heart disease (RHD) disease burden trends over a 30-year period (1991 to 2021), focusing on prevalence, deaths, and disability-adjusted life years (DALYs) in the South Asia (SA). Methods: In this ecological study, we analyzed data regarding burden of RHD from the Global Burden of Diseases (GBD) study spanning the years 1991 to 2021 for the SA Region. Estimates of the number RHD-related prevalence, deaths, and DALYs along with age-standardized rates (ASR) per 100,000 population and 95% uncertainty intervals (UI) were evaluated. Results: The overall prevalent cases of RHD in the 2021 were 54785.1 × 103 (43328.4 × 103 to 67605.5 × 103), out of which 14378.8 × 103 (11206.9 × 103 to 18056.9 × 103) were from SA. The ASR of point prevalence showed upward trend between 1991 and 2021, at global level and for SA with an average annual percentage change (AAPC) of 0.40 (0.39 to 0.40) and 0.12 (0.11 to 0.13), respectively. The overall number of RHD-related deaths in the 2021 were 373.3 × 103 (324.1 × 103 to 444.8 × 103), out of which 215 × 103 (176.9 × 103 to 287.8 × 103) were from SA, representing 57.6% of the global deaths. The ASR of deaths also showed downward trend between 1991 and 2021, at global level and for SA with an AAPC of -2.66 (-2.70 to -2.63) and -2.07 (-2.14 to -2.00), respectively. The ASR of DALYs showed downward trend between 1990 and 2019, at global level and for South Asian region with an AAPC of -2.47 (-2.49 to -2.44) and -2.22 (-2.27 to -2.17), respectively. Conclusion: The rising age-standardized prevalence of RHD remains a global concern, especially in South Asia which contribute to over 50% of global RHD-related deaths. Encouragingly, declining trends in RHD-related deaths and DALYs hint at progress in RHD management and treatment on both a global and regional scale.

SEM and LM insights: Spore morphology and its taxonomic significance in Sino Himalayan, Malesian, and European elements of Pteridaceae.

The Pteridaceae family, known for its taxonomic complexity, presents challenges in identification due to high variability among its species. This study investigates the spore morphology employing both SEM and LM techniques in 10 Pteridaceae taxa phytogeographicaly Sino-Himalayan, Malesian, and European elements in Pakistan. The taxa include Adiantum capillus-veneris, A. incisum, A. venustum, Aleuritopteris bicolor, Oeosporangium nitidulum, O. pteridioides, Onychium cryptogrammoides, O. vermae, Pteris cretica, and P. vittata. The objective is to assess their taxonomic relevance and develop a spore-based taxonomic key. Findings indicate differences in spore shape, sizes, exospore thickness, and in surface ornamentation highlighting the potential for taxonomic differentiation. Spores are trilete, and notable differences are observed in the dimension of spores in both distal and proximal sides. Equatorial dimensions vary between 35 and 50 µm, while the polar diameter ranges from 29 to 50 µm. SEM revealed different spore ornamentation types that show several useful characteristics establishing valuable taxonomic variations. The studied Adiantum taxa feature a perispore with tubercules and a micro-granulose surface. The spores of examined Oeosporangium and Aleuritopteris taxa shows cristate sculptures with variable ornamentations. Both species of Onychium have tuberculate-pleated tubercles with sinuous folds on both distal and proximal sides. The surface ornamentation among examined Pteris taxa show variability. PCA analysis indicated that spore quantitative data identified distinct groups, underscoring taxonomic significance. Nevertheless, there was variation observed in surface ornamentation and spore shape, indicating the potential for discrimination among taxa. RESEARCH HIGHLIGHTS: Spore morphology of 10 Pteridaceae taxa has been investigated through LM and SEM. Investigated species shows differences in spore shape, sizes, exospore thickness, and in surface ornamentation. Ornamentation on the perispore provides several valuable characteristics, establishing useful taxonomic distinctions. Spore morphological analysis is effective at the generic level, with minor distinctions discernible at the species level.

Putting Biochar in Action: A Black Gold for Efficient Mitigation of Salinity Stress in Plants. Review and Future Directions.

Soil salinization is a serious concern across the globe that is negatively affecting crop productivity. Recently, biochar received attention for mitigating the adverse impacts of salinity. Salinity stress induces osmotic, ionic, and oxidative damages that disturb physiological and biochemical functioning and nutrient and water uptake, leading to a reduction in plant growth and development. Biochar maintains the plant function by increasing nutrient and water uptake and reducing electrolyte leakage and lipid peroxidation. Biochar also protects the photosynthetic apparatus and improves antioxidant activity, gene expression, and synthesis of protein osmolytes and hormones that counter the toxic effect of salinity. Additionally, biochar also improves soil organic matter, microbial and enzymatic activities, and nutrient and water uptake and reduces the accumulation of toxic ions (Na+ and Cl), mitigating the toxic effects of salinity on plants. Thus, it is interesting to understand the role of biochar against salinity, and in the present Review we have discussed the various mechanisms through which biochar can mitigate the adverse impacts of salinity. We have also identified the various research gaps that must be addressed in future study programs. Thus, we believe that this work will provide new suggestions on the use of biochar to mitigate salinity stress.