Biology subjects

Pant, B.

Publications and source records attributed to Pant, B..

5 recordsLinked to original sources

bioRxiv2026

Variovorax paradoxus alters the root microbiome and alleviates bicarbonate-induced Fe limitation in cotton (Gossypium hirsutum L.) with enhanced benefits from bilateral root inoculation

Alkaline and calcareous soils can induce iron (Fe) limitation in plants, yet the responses of root-associated microbial communities to beneficial rhizobacteria under these conditions remain poorly understood in cotton. Here, we investigated the effects of Variovorax paradoxus on plant performance, Fe nutrition, and root microbiome dynamics in cotton exposed to bicarbonate-induced Fe limitation. In this study, V. paradoxus inoculation under bicarbonate-induced Fe limitation significantly improved photosynthetic parameters, growth parameters, and tissue Fe status. Interestingly, V. paradoxus partially suppressed the Fe-deficiency-induced increase in root ferric-chelate reductase activity without further increasing rhizosphere siderophore activity. This response suggests that improved Fe availability reduced the demand for maximal activation of the intrinsic Strategy I response. Despite improved plant health, V. paradoxus reduced root C levels, suggesting altered belowground carbon utilization associated with bacterial inoculation and stress conditions. Split-root experiments further showed that inoculating both root compartments showed substantially greater recovery than unilateral inoculation, indicating that broader root exposure to V. paradoxus enhanced the beneficial response. Although bacterial alpha diversity remained unchanged, V. paradoxus significantly altered bacterial community composition and enriched Cellvibrio together with the fungal taxa Funneliformis and Dominikia under Fe limitation. Exploratory analysis identified the plant-beneficial fungal hubs Funneliformis and Serendipita in the V. paradoxus-treated community under indirect Fe deficiency, along with the core genera Pseudomonas, Hydrogenophaga, and Funneliformis and the indicator taxa Shinella and Aquabispora. Spearman correlation analysis further associated Streptomyces with root Fe accumulation and biomass, while Epicoccum and Sordariales were positively associated with siderophore production in cotton exposed to bicarbonate-induced Fe limitation and inoculated with V. paradoxus. These findings demonstrate the potential of V. paradoxus and identify candidate microbial partners for microbiome-informed biofertilizers to improve Fe nutrition in cotton grown in calcareous soils.

plant biology↗

bioRxiv2026

Localized co-inoculation of Bacillus subtilis and Trichoderma afroharzianum acts synergistically to reshape the root microbiome and improve plant performance in sorghum

Despite their agricultural potential, how bacterial-fungal consortia reshape root microbiomes and improve crop performance in sorghum remains poorly understood. Here, we investigated how individual and combined inoculation with Bacillus subtilis and Trichoderma afroharzianum influenced sorghum performance and root microbiome assembly. The in vitro co-culture assay demonstrated the compatibility of B. subtilis and T. afroharzianum as a microbial consortium. The B. subtilis-T. afroharzianum consortium demonstrated the highest CPPI (composite plant performance index) and shoot fresh weight in sorghum, while all inoculation treatments improved multiple growth and physiological traits. Split-root analysis demonstrated that bilateral root co-inoculation was necessary to maximize whole-plant growth benefits. Also, B. subtilis-T. afroharzianum co-inoculation increased carbon levels in both roots and leaves, accompanied by enhanced rhizosphere siderophore production consistent with improved nutrient status. In microbial community analysis, neither bacterial nor fungal alpha or beta diversity differed significantly among treatments; instead, inoculation selectively restructured root microbial communities. The B. subtilis-T. afroharzianum consortium selectively enriched plant growth-promoting Actinoplanes, siderophore-producing Enterobacter, and the plant-beneficial fungal genus Podospora. Co-occurrence network analysis identified Rhodoplanes, Serendipita, and Zopfiella among hub taxa associated with B. subtilis-T. afroharzianum co-inoculation, suggesting potential roles in microbial community connectivity and organization. Furthermore, the persistence of Streptomyces and Serendipita, particularly the latter, suggests the presence of a beneficial microbial core that may contribute to sustained rhizosphere functioning. In addition, Bacillus and Serendipita were among the indicator taxa associated with inoculated treatment combinations, suggesting that the inoculants selectively assembled a distinct plant-beneficial microbiome. Devosia was associated with chlorophyll content, siderophore production, and shoot height, whereas Serendipita correlated with shoot biomass under the B. subtilis-T. afroharzianum co-inoculation. Taken together, B. subtilis-T. afroharzianum consortium promotes sorghum growth by selectively reshaping the root microbiome, highlighting its potential as a next-generation microbial biofertilizer.

plant biology↗

bioRxiv2025

NF-kB-Dependent Transcriptional Regulation of Piezo1 Mediates Bacterial Clearance on Stiffened Lung

Respiratory pathogens, such as Pseudomonas aeruginosa damage the alveolar-capillary barrier leading to lung injury and stiffness. Lung stiffness is a key macrophage signal for bacterial clearance, but it remains unknown how stiffness-sensing mechanosensitive ion channels in macrophages are regulated during pneumonia. Macrophage Piezo1 is critical to bacterial clearance in experimental pneumonia in vivo; however, identification of putative matrix-derived signals and the mechanism of their effects remain to be determined. To our knowledge, our work is the first to show that during pneumonia, transcription of the mechanosensitive ion channel Piezo1 is increased in macrophages by the NF-{kappa}B transcription factor, p65, through its signaling adaptor protein, MyD88, leading to increased Piezo1 Ca2+ channel activity. Piezo1 mRNA abundance is increased in association with open chromatin at the Piezo1 promoter in macrophages. The enhanced level of Piezo1 increases the abundance of transcription factor EB (Tfeb) resulting in lysosome biogenesis and stiffness-dependent phagolysosome maturation, a critical step for macrophage bacterial clearance. Our data support the mechanism whereby transcription of macrophage Piezo1 is enhanced by p65 to augment bacterial clearance on an injured, stiffened lung matrix during pneumonia. Therefore, Piezo1 is a future therapeutic target against pneumonia-induced lung injury.

immunology↗

bioRxiv2025

Micropropagation and Assessment of Genetic Homogeneity in Dendrobium moniliforme (L.) Sw. using Molecular Markers

Dendrobium moniliforme (L.) Sw., is a valuable medicinal orchid widely used as tonic. This study aimed to develop an effective protocol for micropropagation of D. moniliforme and to compare the genetic similarities of the micro-propagated plants to the wild plants using Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeats (ISSR) molecular markers. Healthy seeds were cultured on Murashige-Skoog (MS) medium, supplemented with various concentrations of auxins, cytokinins and coconut water for shoot and root development. Genetic homogeneity was assessed using ten primers of each RAPD and ISSR marker. MS media fortified with 10% coconut water was efficient for seed germination and protocorm development. Maximum number of shoots were produced on half strength MS (HMS) medium supplemented with 0.25 mg/L NAA and 10% coconut water (CW) i.e 22 shoots. FMS supplemented with 0.5 mg/L indole butyric acid (IBA) was found to be best as plant hormone for root induction, as it induced ten roots/shoot. RAPD and ISSR amplified a total of 15 and 5 homogeneous DNA fragments. This protocol demonstrates a reliable and efficient method for large-scale propagation and conservation of D. moniliforme, supporting its commercial and medicinal value. HighlightsDendrobium moniliforme was micro-propagated from seeds using MS medium. RAPD and ISSR markers confirmed its genetic stability. The study supports large-scale true-to-type propagation and conservation of these valuable medicinal orchids.

molecular biology↗

bioRxiv2025

Could malaria mosquitoes be controlled by periodic releases of transgenic mosquitocidal Metarhizium pingshaense fungus? A mathematical modeling approach

Insect pathogenic fungi offer a promising alternative to chemical insecticides for controlling insecticide resistant mosquitoes. One proposed method involves releasing male Anopheles mosquitoes contaminated with transgenic Metarhizium pingshaense (Met-Hybrid), to lethally infecting females during mating. This study presents a novel deterministic mathematical model to evaluate the impact of this control approach in malaria-endemic areas. The model incorporates two fungus transmission pathways: mating-based transmission and indirect transmission through contact with fungus-colonized mosquito cadavers. We found the fungus cannot establish in the mosquito population without transmission from infected cadavers (in this scenario, the reproduction number of the model is zero). However, if transmission from colonized cadavers is possible, the fungus can persist in the local mosquito population when the reproduction number exceeds one. Simulations of periodic releases of infected male mosquitoes, parameterized using Met-Hybrid-exposed mosquito data from Burkina Faso, show that an 86% reduction in the local female mosquito population can be achieved by releasing 10 Met-Hybrid-exposed male mosquitoes per wild mosquito every three days over six months. This matches the efficiency of some genetic mosquito control approaches. However, a 90% reduction in the wild mosquito population requires, for instance, daily releases of the fungal-treated mosquitoes in a 6:1 ratio for about 5 months, proving less efficient than some genetic approaches. This study concludes that fungal programs with periodic releases of infected males may complement other methods or serve as an alternative to genetic-based mosquito control methods, where regulatory, ethical, or public acceptance concerns restrict genetically-modified mosquito releases.

ecology↗