Background: The dehydration responsive element-binding (DREB) gene family plays a crucial role as transcription regulators and enhances plant tolerance to abiotic stresses. Although the DREB gene family has been identified and characterized in many plants, knowledge about it in Solanum tuberosum (Potato) is limited. Results: In the present study, StDREB gene family was comprehensively analyzed using bioinformatics approaches. We identified 66 StDREB genes through genome wide screening of the Potato genome based on the AP2 domain architecture and amino acid conservation analysis (Valine at position 14th). Phylogenetic analysis divided them into six distinct subgroups (A1–A6). The categorization of StDREB genes into six subgroups was further supported by gene structure and conserved motif analysis. Potato DREB genes were found to be distributed unevenly across 12 chromosomes. Gene duplication proved that StDREB genes experienced tandem and segmental duplication events which led to the expansion of the gene family. The Ka/Ks ratios of the orthologous pairs also demonstrated the StDREB genes were under strong purification selection in the course of evolution. Interspecies synteny analysis revealed 45 and 36 StDREB genes were orthologous to Arabidopsis and Solanum lycopersicum, respectively. Moreover, subcellular localization indicated that StDREB genes were predominantly located within the nucleus and the StDREB family’s major function was DNA binding according to gene ontology (GO) annotation. Conclusions: This study provides a comprehensive and systematic understanding of precise molecular mechanism and functional characterization of StDREB genes in abiotic stress responses and will lead to improvement in Solanum tuberosum.

Nitrogen (N) losses are prevalent under South East Asia’s due to high N fertilizer inputs, but low N fertilizer use efficiency. This leaves a large quantity of reactive N at risk of loss to the environment. Biochar has been found to reduce N losses across a variety of soil types, however, there is limited data available for semi-arid climates, particularly at a field-scale. Herein we present an exploration of the biological and chemical enhancement effects observed of a cotton stalk-based biochar on wheat growth and yield under arid field conditions. The biochar was treated with urea-N and biofertilizer (bio-power) in different treatment setups. The six experimental treatments included; (i) a full N dose “recommended for wheat crops in the region” (104 kg N ha⁻¹) as a positive control; (ii) a half N dose (52 kg N ha⁻¹); (iii) a half N dose + biofertilizer (4.94 kg ha⁻¹) as a soil mixture; (iv) a half N dose + biofertilizer as a seed inoculation; (v) a full N dose as broadcast + biochar (5 t ha⁻¹) inoculated with biofertilizer; and (vi) a full N dose loaded on biochar + biofertilizer applied as a soil mixture. The half dose N application or biofertilizer addition as soil mix/seed inoculated/biochar inoculation with biofertilizer caused reduced wheat growth and yield compared to the control (conventional N fertilization). However, co-application of chemically enhanced biochar (loaded with a full N dose) and biofertilizer as soil mixture significantly increased the crop growth rate (CGR) and leaf area index (LAI). A significantly higher crop growth and canopy development led to a higher light interception and radiation use efficiency (RUE) for total dry matter (TDM) and grain yield (11% greater than control) production compared to the control. A greater grain yield, observed for the full N dose loaded on biochar + biofertilizer applied as a soil mixture, is attributed to prolonged N availability as indicated by greater plant and soil N content at harvest and different crop growth stages, respectively. The present study has improved our understanding of how the application of nitrogen loaded biochar and biofertilizer as soil mixtures can synergize to positively affect wheat growth and soil-nitrogen retention under arid environmental conditions.

Drought is one of the hostile environmental stresses that limit the yield production of crop plants by modulating their growth and development. Peanut (Arachis hypogaea) has a wide range of adaptations to arid and semi-arid climates, but its yield is prone to loss due to drought. Other than beneficial fatty acids and micronutrients, peanut harbors various bioactive compounds including flavonoids that hold a prominent position as antioxidants in plants and protect them from oxidative stress. In this study, understanding of the biosynthesis of flavonoids in peanut under water deficit conditions was developed through expression analysis and correlational analysis and determining the accumulation pattern of phenols, flavonols, and anthocyanins. Six peanut varieties (BARD479, BARI2011, BARI2000, GOLDEN, PG1102, and PG1265) having variable responses against drought stress have been selected. Higher water retention and flavonoid accumulation have been observed in BARI2011 but downregulation has been observed in the expression of genes and transcription factors (TFs) which indicated the maintenance of normal homeostasis. ANOVA revealed that the expression of flavonoid genes and TFs is highly dependent upon the genotype of peanut in a spatiotemporal manner. Correlation analysis between expression of flavonoid biosynthetic genes and TFs indicated the role ofAhMYB111andAhMYB7as an inhibitor forAhF3HandAhFLS, respectively, andAhMYB7, AhTTG1, andAhCSU2as a positive regulator for the expression ofAh4CL, AhCHS, and AhF3H, respectively. However,AhbHLHandAhGL3revealed nil-to-little relation with the expression of flavonoid biosynthetic pathway genes. Correlational analysis between the expression of TFs related to the biosynthesis of flavonoids and the accumulation of phenolics, flavonols, and anthocyanins indicated coregulation of flavonoid synthesis by TFs under water deficit conditions in peanut. This study would provide insight into the role of flavonoid biosynthetic pathway in drought response in peanut and would aid to develop drought-tolerant varieties of peanut.

Stilbene synthase is an important enzyme of the phenylpropanoid pathway, regulating the production of several biologically active stilbenoids. These compounds have antioxidant, anti-inflammatory, and anti-cancer properties. However, the detailed characterization of stilbene synthase genes in Arachis hypogaea has not yet been performed. In this study, the comprehensive characterization of stilbene synthase genes in A. hypogaea was conducted, commencing with identification, phylogenetic analysis, and study of their expression in response to exogenous hormonal treatment. We identified and isolated five AhSTSs genes and recorded their expression pattern in peanut (BARD-479) in response to methyl jasmonate (MeJA) and salicylic acid (SA) treatment. The presence of Chal_sti_synt, ACP_syn_III, and FAE1_CUT1_rppA domains in all AhSTSs indicated their role in the biosynthesis of stilbene and lipid metabolism. Cis-regulatory element analysis indicated their role in light responsiveness, defense responses, regulation of seed development, plant growth, and development. Despite close structural and functional similarities, expression and correlational analysis suggested that these genes may have a specific role in peanut, as individual AhSTS exhibited differential expression upon hormonal treatment in a genotype dependent manner. Further studies on functional characterization involving the transcriptional regulation of AhSTSs can clearly explain the differential expression of stilbene synthase genes to hormonal treatment.

Nanotechnology offers several advantages over conventional inputs, with widespread application in agriculture. The current climate change crisis has accelerated the accumulation of salts in soils, which is a major challenge to global food security. Here, we synthesized fulvic acid‐releasing chitosan nanoparticles (Ch‐FANPs) for promoting soybean growth and salt stress tolerance. In a screening hydroponic experiment, 0.1 mM Ch‐FANPs promoted plant growth and enhanced the growth parameters of pot‐grown soybean plants significantly and modulated stomatal movement under control as well as salt stress conditions induced by 150 mM NaCl. Salt stress affected overall plant growth and reduced the chlorophyll content. However, plants treated with Ch‐FANPs not only accumulated significantly higher chlorophyll under both control and salt conditions but also enhanced several above‐ and below‐ground growth parameters by more than 50%. Interestingly, the Ch‐FANP‐treated salt‐exposed plants accumulated ~30% less soluble proteins than untreated salt‐stressed plants. Ch‐FANPs‐mediated protection against salt stress was related to the activation of antioxidant machinery as the highest ascorbate peroxidase (APX) activity was recorded in Ch‐FANPs‐treated salt‐stressed plants along with significantly low MDA and H₂O₂ contents. ICP‐MS analysis showed a tremendously higher accumulation of Na⁺ ions (~35 ppm) in the leaves of salt‐stressed plants compared to 19 ppm Na⁺ ions when also treated with Ch‐FANPs. Salt‐exposed plants treated with Ch‐FANPs had the highest K⁺ content (~76 ppm) and Ca²⁺ (62 ppm). Furthermore, Ch‐FANPs‐mediated protection against salt stress was associated with a significant increase in the expression of salt stress marker genes GmSOS1, GmSOS2, GmNHX1, and GmP5CS1.