Salinity has emerged as a critical abiotic stress factor, significantly limiting the growth, productivity, and quality of many crop species. As the global salinization of agricultural land continues to intensify, it is crucial to explore effective mitigation strategies to sustain crop yields. γ-Aminobutyric acid (GABA), a non-protein amino acid, is present in a variety of organisms, including plants, where it fulfills diverse roles under both optimal and stress conditions. In plants, GABA is intricately involved in nitrogen metabolism, amino acid biosynthesis, and the regulation of primary and secondary metabolic pathways. Functioning through the GABA shunt, it provides the carbon skeletons and energy required for biosynthetic processes and is vital for the regulation of carbon and nitrogen balance. Under abiotic stress conditions, particularly salinity, GABA rapidly accumulates, facilitating several protective mechanisms that help plants cope with stress. These include enhancing osmotic adjustment through the accumulation of osmolytes, protecting cellular structures such as chloroplasts, and improving chlorophyll fluorescence and photosynthetic efficiency. Moreover, GABA has been shown to boost antioxidant enzyme activity, reducing oxidative stress and mitigating the damage caused by reactive oxygen species (ROS) under salinity conditions. This study explores the multifaceted role of GABA in plants under saline environments, with a focus on its physiological, biochemical, and molecular mechanisms in enhancing plant resilience. By elucidating these mechanisms, we aim to highlight the potential of GABA as a natural biostimulant to improve crop performance and sustainability in saline soils.

Pseudomonas aeruginosa is an opportunistic gram-negative human pathogen that causes a wide range of infections, including nosocomial infections. Aside from the intrinsic and acquired antimicrobial resistance against many classes of antibiotics, P. aeruginosa can produce an extracellular polymeric matrix called “biofilm” that protects bacteria from antibiotics and harmful factors. Biofilm enables P. aeruginosa to develop chronic infections. This study assessed the inhibitory action of ZnO-nanoparticles against biofilms formed by multidrug-resistant P. aeruginosa strains. A collection of 24 clinical strains of P. aeruginosa were tested for their antimicrobial resistance against different antibiotics using the disk diffusion method. The antibiofilm activity of ZnO-NPs was assessed using the microtiter plate biofilm assay. The application of ZnO-NPs dramatically modulated the resistance profile and biofilm activity of P. aeruginosa. The combination of ZnO-NPs and meropenem showed synergistic antipseudomonal activity with lower MICs. The scanning electron microscope (SEM) micrographs revealed complete inhibition of biofilms treated with the meropenem–ZnO-NPs combination. Reduced expression of biofilm regulating genes lasR, pslA, and fliC was detected, reflecting the enhanced antibiofilm effect of ZnO-NPs. In vivo application of this antimicrobial mixture completely cured P. aeruginosa-induced keratitis in rats. Our findings represent a dual enhancement of antibacterial and antibiofilm activity via the use of meropenem–ZnO-NPs combination against carbapenem-resistant P. aeruginosa infections.

Background: Drought stress represents a significant threat to crop productivity, particularly in regions characterized by water scarcity. This study investigated the potential of utilizing endophytic fungi to enhance drought tolerance in maize (Zea mays L.). Specifically, we aimed to investigate the role of these fungi in improving the physiological, morphological, and molecular responses of maize plants subjected to drought conditions. Results: Our findings revealed a significant contribution of endophytic fungi in mitigating the adverse effects of drought stress. Morphological analysis revealed higher root and shoot growth in treated plants compared to untreated controls, indicating improved water uptake and retention capabilities. Furthermore, physiological parameters, including chlorophyll content, markedly increased in fungus-treated plants under drought conditions. The activities of enzymatic antioxidants, including catalase (CAT), peroxidase (POX), and polyphenol oxidase (PPO), in maize plants inoculated with R. arrhizus under severe drought stress conditions were increased by 157.71%, 92.14%, and 144.44%, respectively, compared to those of the non-bioprimed plants. Endophytic inoculation resulted in a reduction of H₂O₂ and MDA levels by 48% and 55.11%, respectively, compared to non-inoculated plants. At the molecular level, ISSR analysis revealed distinct banding patterns between inoculated and non-inoculated plants under drought stress, indicating genomic variation linked to the presence of endophytic fungi. These molecular fingerprints suggest the activation of stress-responsive pathways and highlight the potential role of endophytes in enhancing plant drought tolerance. Collectively, these results highlight the potential of utilizing endophytic fungi as a sustainable and eco-friendly approach to enhance drought tolerance in maize, offering promising implications for agricultural practices in arid and semiarid regions. Conclusions: This study represents one of the few investigations detailing the practical application of endophytic fungi-especially Rhizopus arrhizus, in mitigating the detrimental effects of drought stress caused by limited water availability. These findings raise the possibility of utilizing endophytes suited to dry environments within agricultural systems.

Peach fruit is susceptible to deterioration, such as browning, highlighting the importance of applying effective preservation treatments to maintain quality. This study investigated the effect of progesterone (PRG) on the storability of mature peach fruit (cv. ‘Early Swelling’). In the initial experiment, response surface methodology (RSM) was applied to evaluate key quality indicators, including browning, firmness, proline, and gamma‐aminobutyric acid (GABA) content to determine the optimal PRG concentration (1–30 µM) and treatment duration (1–30 min). Based on the RSM findings, a second experiment was applied using either 10 or 15 µM PRG for 10 min, selected as optimal conditions, compared with untreated controls. The peach fruits were stored at 2°C with 90–95% RH for 32 days. The findings demonstrated that all PRG treatments efficiently preserved fruit quality and prolonged storability relative to the control. PRG treatment at 15 µM showed superior efficacy, significantly reducing browning, malondialdehyde, and weight loss while sustaining total phenolics, firmness, and DPPH radical scavenging activity. Moreover, PRG treatments enhanced pectin methylesterase activity, proline levels, and GABA content. These outcomes suggest that PRG application is a promising approach for improving peach fruit storability, minimising postharvest deterioration, and maintaining quality during extended storage.