Deciphering the impact of cold-adapted bioinoculants on rhizosphere dynamics, biofortification, and yield of kidney bean across varied altitudinal zones

Agriculture stands as a thriving enterprise in India, serving as both the bedrock of economy and vital source of nutrition. In response to the escalating demands for high-quality food for swiftly expanding population, agricultural endeavors are extending their reach into the elevated terrains of the Himalayas, tapping into abundant resources for bolstering food production. Nonetheless, these Himalayan agro-ecosystems encounter persistent challenges, leading to crop losses. These challenges stem from a combination of factors including prevailing frigid temperatures, suboptimal farming practices, unpredictable climatic shifts, subdivided land ownership, and limited resources. While the utilization of chemical fertilizers has been embraced to enhance the quality of food output, genuine concerns have arisen due to the potential hazards they pose. Consequently, the present investigation was initiated with the objective of formulating environmentally friendly and cold-tolerant broad ranged bioinoculants tailored to enhance the production of Kidney bean while concurrently enriching its nutrient content across entire hilly regions. The outcomes of this study unveiled noteworthy advancements in kidney bean yield, registering a substantial increase ranging from 12.51 ± 2.39 % to 14.15 ± 0.83 % in regions of lower elevation (Jeolikote) and an even more remarkable surge ranging from 20.60 ± 3.03 % to 29.97 ± 5.02 % in higher elevated areas (Chakrata) compared to the control group. Furthermore, these cold-tolerant bioinoculants exhibited a dual advantage by fostering the enhancement of essential nutrients within the grains and fostering a positive influence on the diversity and abundance of microbial life in the rhizosphere. As a result, to effectively tackle the issues associated with chemical fertilizers and to achieve sustainable improvements in both the yield and nutrient composition of kidney bean across varying elevations, the adoption of cold-tolerant Enterobacter hormaechei CHM16, and Pantoea agglomerans HRM 23, including the consortium, presents a promising avenue. Additionally, this study has contributed significant insights-into the role of organic acids like oxalic acid in the solubilization of nutrients, thereby expanding the existing knowledge in this specialized field.

First Report of Green Mould on Leaf of Phaseolus vulgaris Caused by Cladosporium tenuissimum in Liaoning, China

Phaseolus vulgaris Linn. is a widely cultivated vegetable throughout the world. From spring 2019 to 2022, green mould symptoms were observed on leaves of P. vulgaris in the greenhouse in Liaoning, China, with disease incidence of 8-75% (plants) and 6-23% (leaves). Symptoms appeared as chlorotic lesions covered with dark green mould. The infections started at the apex or margin of the leaves and then spread inward with a characteristic "V" shape. Lesions exhibited curly morphology. 15 leaf samples with typical symptoms were collected from 5 different greenhouses. A total of 75 (5 replicates of each sample) leaf tissues (0.5 cm × 0.5 cm) were selected from the boundary between diseased and healthy parts. These samples were surface sterilized in 0.5% NaClO formin, rinsed 3 times in sterile distilled water and subsequently incubated at 28℃ on potato dextrose agar (PDA) supplemented with streptomycin (50 μg/ml). Numerous morphologically uniform colonies had been purified, with no other fungi observed. Afterwards, the strains were subcultured on malt extract agar (MEA). Colonies on MEA reached 70 to 80 mm diam after 14 days, smoke-grey to pale olivaceous-grey, woolly, sometimes radially wrinkled. The mycelia were pale olivaceous-grey, with hyphae measuring 1-5 μm wide (n = 20). The conidiophores were solitary or in groups of 2 to 5, and measured 50-280(-350) × 2.5-4 μm (n = 20), with 2-7 septa. The conidiogenous cells exhibited a cylindrical-oblong morphology and measured 10-44 × 5 μm (n = 20), with 0-2 septa, and the loci frequently thickened. The conidia were catenate in densely branched chains, ellipsoid to obovoid, smooth, and measured 2.5-5 × 2-3 μm (n = 50), with 0-4 septa. The morphological characteristics were similar to Cladosporium tenuissimum (Zhang 2003). The representative isolate KZ-19 was selected for molecular identification. The rDNA-ITS, translation elongation factor 1-α and actin genes were amplified, sequenced, and the resulting sequence data were submitted to GenBank (ITS: OQ931048; EF-1α: OQ954495; ACT: OQ954496). The BLAST results exhibited a 99 to 100% similarity with the sequences of C. tenuissimum type strain CBS 125995(ITS: HM148197; EF-1α: HM148442; ACT: HM148687). Furthermore, a multi-locus phylogenetic tree was constructed using the PhyloSuite (v 1. 2. 2) software, which revealed that the strains were most closely related to C. tenuissimum (Zhang et al. 2020). Based on both morphological and molecular characteristics, KZ-19 was finally identified as C. tenuissimum (Bensch 2012). Pathogenicity testing was performed on healthy 1-month-old P. vulgaris plants by inoculating the spore suspension (1×106 conidia/ml) of KZ-19 onto leaf surfaces, while control plants were simulated inoculated with sterile water, and five pots were used for each treatment. The test was performed under field conditions of 16-28°C (temperature) and 24-56% (relative humidity). Chlorotic lesions became evident within 2 days of inoculation, followed by the appearance of green mold on leaves after 7 days. No symptoms were observed in the control group. To fulfill Koch's postulates, the pathogen was re-isolated from three inoculated leaves. The morphological identification of re-isolated pathogens was similar to that of originally isolated pathogens. No infection was observed in non-inoculated control. To the best of our knowledge, this is the first report of C. tenuissimum causing green mould on P. vulgaris. As a ubiquitous saprobic hyphomycete, C. tenuissimum has been implicated in leaf mold in Punica granatum and Trifolium repens, larch bud blight, and strawberry blossom blight in previous years (He et al. 1987; Zhang et al. 2003; Zheng et al. 2010; Nam et al. 2015), presenting a potential threat to numerous crops. Therefore, an investigation of its distribution and pathogenic potential is essential in addition to the development of effective disease management strategies.

Synthesis and characterization of nano starch-based composite films from kidney bean (Phaseolus vulgaris)

This study was aimed to synthesize and evaluate the nano starch-based composite films by the addition of nano starch in film formulation at 0.5, 1, 2, 5 and 10% level of total starch. The acid hydrolysis technique was used to reduce the size of starch granules of kidney bean starch. The physicochemical properties of both native and nano starch were determined. Nano starch showed a higher value for swelling power, solubility, water and oil absorption capacity when compared with native starch. The particle size of kidney bean nano starch was 257.7 nm at 100% intensity. The size of starch granule affects various properties of films. The thickness, solubility and burst strength of the composite films were increased significantly (p ≤ 0.05) with an increase in the concentration of nano starch in film formulation. While the moisture content and water vapour transmission rate (WVTR) were decreased significantly (p ≤ 0.05) with an increase in the concentration of nano starch in film formulation. The results suggested that kidney bean starch could be used for the development of packaging films. The utilization of nano starch in film formulations had an additional advantage in improving the film properties.

Heavily Graphitic-Nitrogen Self-doped High-porosity Carbon for the Electrocatalysis of Oxygen Reduction Reaction

Large-scale production of active and stable porous carbon catalysts for oxygen reduction reaction (ORR) from protein-rich biomass became a hot topic in fuel cell technology. Here, we report a facile strategy for synthesis of nitrogen-doped porous nanocarbons by means of a simple two-step pyrolysis process combined with the activation of zinc chloride and acid-treatment process, in which kidney bean via low-temperature carbonization was preferentially adopted as the only carbon-nitrogen sources. The results show that this carbon material exhibits excellent ORR electrocatalytic activity, and higher durability and methanol-tolerant property compared to the state-of-the-art Pt/C catalyst for the ORR, which can be mainly attributed to high graphitic-nitrogen content, high specific surface area, and porous characteristics. Our results can encourage the synthesis of high-performance carbon-based ORR electrocatalysts derived from widely-existed natural biomass.

Soil organic matter influences cerium translocation and physiological processes in kidney bean plants exposed to cerium oxide nanoparticles

Soil organic matter plays a major role in determining the fate of the engineered nanomaterials (ENMs) in the soil matrix and effects on the residing plants. In this study, kidney bean plants were grown in soils varying in organic matter content and amended with 0-500mg/kg cerium oxide nanoparticles (nano-CeO2) under greenhouse condition. After 52days of exposure, cerium accumulation in tissues, plant growth and physiological parameters including photosynthetic pigments (chlorophylls and carotenoids), net photosynthesis rate, transpiration rate, and stomatal conductance were recorded. Additionally, catalase and ascorbate peroxidase activities were measured to evaluate oxidative stress in the tissues. The translocation factor of cerium in the nano-CeO2 exposed plants grown in organic matter enriched soil (OMES) was twice as the plants grown in low organic matter soil (LOMS). Although the leaf cover area increased by 65-111% with increasing nano-CeO2 concentration in LOMS, the effect on the physiological processes were inconsequential. In OMES leaves, exposure to 62.5-250mg/kg nano-CeO2 led to an enhancement in the transpiration rate and stomatal conductance, but to a simultaneous decrease in carotenoid contents by 25-28%. Chlorophyll a in the OMES leaves also decreased by 27 and 18% on exposure to 125 and 250mg/kg nano-CeO2. In addition, catalase activity increased in LOMS stems, and ascorbate peroxidase increased in OMES leaves of nano-CeO2 exposed plants, with respect to control. Thus, this study provides clear evidence that the properties of the complex soil matrix play decisive roles in determining the fate, bioavailability, and biological transport of ENMs in the environment.