Plant-specific GRAS transcription factors play important roles in regulating growth, development, and stress responses. Castor beans (Ricinus communis) are important non-edible oilseed plants, cultivated worldwide for its seed oils and its adaptability to growth conditions. In this study, we identified and characterized a total of 48 GRAS genes based on the castor bean genome. Combined with phylogenetic analysis, the castor bean GRAS members were divided into 13 distinct groups. Functional divergence analysis revealed the presence of mostly Type-I functional divergence. The gene structures and conserved motifs, both within and outside the GRAS domain, were characterized. Gene expression analysis, performed in various tissues and under a range of abiotic stress conditions, uncovered the potential functions of GRAS members in regulating plant growth development and stress responses. The results obtained from this study provide valuable information toward understanding the potential molecular mechanisms of GRAS proteins in castor beans. These findings also serve as a resource for identifying the genes that allow castor beans to grow in stressful conditions and to enable further breeding and genetic improvements in agriculture.

Eruca sativa Mill. is an underutilized crop for the production of oil. Evaluating the exact potential of E. sativa oil quantity and quality, and salinity-associated physiological adaptations with low-quality saline water would be helpful for making decisions about its large-scale cultivation on marginal lands. A lysimeter (drum-pot) experiment was conducted under a series of saline water irrigation (EC_iw 0.72, 4.02, 7.32, 10.42, and 13.43 dS.m⁻¹) and the physiological data was taken at the seed-filling stage. The results showed that all the growth and yield parameters declined under higher salinity. The linear regression model showed a 50% reduction in weights of shoots, siliquae, and seeds at irrigation salinity (EC_iw) of 13 dS.m⁻¹. Seed oil content was only significantly declined at higher salinity of EC_iw 13.43 dS.m⁻¹ compared to control. Palmitic and linoleic acids were increased from 4.66 to 6.06% and 9.76 to 13.7%, respectively; and erucic acid declined from 43.7 to 40.35% at higher salinity. Photosynthetic pigments, osmotic potential, K⁺/Na⁺ ratio, and CAT activity significantly declined; and RWC, soluble sugars, proline, Na⁺, K⁺, malondialdehyde, proteins and APX activity were significantly augmented with increasing salinity. The results demonstrate that E. sativa makes osmotic adjustments for survival under salinity and could be grown on marginal lands for industrial oil production.

Plant-derived bioactive compounds contribute a major role in plant defense against fungal pathogens. Among these, coumarin proved to be a major controller in root-pathogen interactions, exhibiting diverse protective mechanisms. This study investigates the effects of coumarin (50 mg.L^− 1), applied through seed priming and foliar spray, on the biochemical responses of Mung bean and its impact on root colonization by Fusarium solani. Mung bean seeds pre-treated with coumarin were sown under both infected and non-infected conditions. Once the seedling established up to two-leaf stage, weekly foliar sprays of 50 mg.L^− 1 coumarin (treatment group) and water (control group) were applied for 4 weeks. The results showed that the application of coumarin significantly reduced Fusarium colonization in Mung bean roots while enhancing shoot and root growth under pathogen stress. Coumarin treatment significantly increased leaf area, shoot density, and photosynthetic pigments. It also caused a substantial reduction in oxidative stress markers, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) contents. Antioxidant enzyme activities, including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and guaiacol peroxidase (GPX) were markedly increased with coumarin treatment. Likewise, enzymes involved in secondary metabolism, such as polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL), also showed increased activities. This was associated with higher levels of total phenolics and flavonoid alongside stronger antioxidant activitiy, indicated by DPPH and ABTS assays. HPLC analysis further revealed increased levels of gallic, coumaric, ferulic, and chlorogenic acids in coumarin-treated plants. These findings demonstrate that coumarin applications enhance the synthesis of beneficial secondary metabolites, strengthen plant defense mechanisms, and promote overall plant health. Therefore, coumarin shows a promising sustainable biostimulant for improving crop resilience and advancing eco-friendly agricultural practices.