Gamma-aminobutyric acid (GABA) is a non-protein amino acid known for its role in the nervous system of animals. However, research has also revealed its presence and function in plants recently. In plants, GABA is a signal molecule involved in multiple physiological processes, including stress response, growth, and development. This review aims to present a thorough summary of the current knowledge regarding the role of GABA in plants. We begin by discussing the biosynthesis and transport of GABA in plants, followed by a detailed examination of its signaling mechanisms. Additionally, we explore GABA's potential roles in various plant physiological processes, such as abiotic stress response, and its potential application in horticultural plants. Finally, we highlight current challenges and future directions for research in this area. Overall, this review offers a comprehensive understanding of the significance of GABA in plants and its potential implications for plant physiology and crop improvement.

There is a very narrow margin in selenium deficiency and toxicity although it is an important element for humans, animals, and plants. Effects of selenium (Se) on the growth and physiomorphological parameters in maize were studied grown in soil spiked with sodium selenate (Na₂SeO₄) in 5 different concentrations (i.e., 0. 2.5, 5.0, 10.0, and 20.0mgkg⁻¹). The growth of plants was affected by high Se concentration. However, maximum increases in plant height and root length were observed at low Se (2.5mgkg⁻¹) which were 17.89 and 23.17, respectively. At higher Se concentrations (20mgkg⁻¹), a considerable reduction was observed in dry matter, root length, antioxidant enzymes, and other physiological parameters. The dry matter of plants was also analyzed for nutrient (Fe and Zn) concentrations. Results indicated that Se stress inhibits plant growth. Gas exchange parameters were also found to be decreased under stress conditions, but at a lower Se level (2.5mgkg⁻¹), improvement in transpiration rate (63.46), photosynthetic rate (47.47), and stomatal conductance (54.55) was observed. The reduction in growth attributes may be due to the high accumulation of Se in roots and the disturbance in gas exchange parameters. However, the principal component analysis revealed that higher Se levels were more hazardous for maize growth and physiological responses as compared to low Se levels.

The cucumber is one of the most important vegetables worldwide and is used as a research model for study of phloem transport, sex determination and temperature-photoperiod physiology. The shoot apex is the most important plant tissue in which the cell fate and organ meristems have been determined. In this study, a series of whole-genome small RNA, degradome and transcriptome analyses were performed on cucumber shoot apical tissues treated with high vs. low temperature and long vs. short photoperiod. A total of 164 known miRNAs derived from 68 families and 203 novel miRNAs from 182 families were identified. Their 4611 targets were predicted using psRobot and TargetFinder, amongst which 349 were validated by degradome sequencing. Fourteen targets of six miRNAs were differentially expressed between the treatments. A total of eight known and 16 novel miRNAs were affected by temperature and photoperiod. Functional annotations revealed that “Plant hormone signal transduction” pathway was significantly over-represented in the miRNA targets. The miR156/157/SBP-Boxes and novel-mir153/ethylene-responsive transcription factor/senescence-related protein/aminotransferase/acyl-CoA thioesterase are the two most credible miRNA/targets combinations modulating the plant’s responsive processes to the temperature-photoperiod changes. Moreover, the newly evolved, cucumber-specific novel miRNA (novel-mir153) was found to target 2087 mRNAs by prediction and has 232 targets proven by degradome analysis, accounting for 45.26–58.88% of the total miRNA targets in this plant. This is the largest sum of genes targeted by a single miRNA to the best of our knowledge. These results contribute to a better understanding of the miRNAs mediating plant adaptation to combinations of temperature and photoperiod and sheds light on the recent evolution of new miRNAs in cucumber.

A steady rise in the overall population is creating an overburden on crops due to their global demand. On the other hand, given the current climate change and population growth, agricultural practices established during the Green Revolution are no longer viable. Consequently, innovative practices are the prerequisite of the time struggle with the rising global food demand. The potential of nanotechnology to reduce the phytotoxic effects of these ecological restrictions has shown significant promise. Nanoparticles (NPs) typically enhance plant resilience to stressors by fortifying the physical barrier, optimizing photosynthesis, stimulating enzymatic activity for defense, elevating the concentration of stress-resistant compounds, and activating the expression of genes associated with defense mechanisms. In this review, we thoroughly cover the uptake and translocations of NPs crops and their potential valuable functions in enhancing plant growth and development at different growth stages. Additionally, we addressed how NPs improve plant resistance to biotic and abiotic stress. Generally, this review presents a thorough understanding of the significance of NPs in plants and their prospective value for plant antioxidant and crop development.