Cotton (Gossypium spp.) is an economically important natural fiber crop. The quality of cotton fiber has a substantial effect on the quality of cotton textiles. The identification of cotton fiber development-related genes and exploration of their biological functions will not only enhance our understanding of the elongation and developmental mechanisms of cotton fibers but also provide insights that could aid the cultivation of new cotton varieties with improved fiber quality. Cotton fibers are single cells that have been differentiated from the ovule epidermis and serve as a model system for research on single-cell differentiation, growth, and fiber production. Genes and fiber formation mechanisms are examined in this review to shed new light on how important phytohormones, transcription factors, proteins, and genes linked to fiber development work together. Plant hormones, which occur in low quantities, play a critically important role in regulating cotton fiber development. Here, we review recent research that has greatly contributed to our understanding of the roles of different phytohormones in fiber development and regulation. We discuss the mechanisms by which phytohormones regulate the initiation and elongation of fiber cells in cotton, as well as the identification of genes involved in hormone biosynthetic and signaling pathways that regulate the initiation, elongation, and development of cotton fibers.

Cotton refers to species in the genus Gossypium that bear spinnable seed coat fibers. A total of 50 species in the genus Gossypium have been described to date. Of these, only four species, viz. Gossypium, hirsutum, G. barbadense, G. arboretum, and G. herbaceum are cultivated; the rest are wild. The black dot-like structures on the surfaces of cotton organs or tissues, such as the leaves, stem, calyx, bracts, and boll surface, are called gossypol glands or pigment glands, which store terpenoid aldehydes, including gossypol. The cotton (Gossypium hirsutum) pigment gland is a distinctive structure that stores gossypol and its derivatives. It provides an ideal system for studying cell differentiation and organogenesis. However, only a few genes involved in the process of gland formation have been identified to date, and the molecular mechanisms underlying gland initiation remain unclear. The terpenoid aldehydes in the lysigenous glands of Gossypium species are important secondary phytoalexins (with gossypol being the most important) and one of the main defenses of plants against pests and diseases. Here, we review recent research on the development of gossypol glands in Gossypium species, the regulation of the terpenoid aldehyde biosynthesis pathway, discoveries from genetic engineering studies, and future research directions.

Plant-specialized metabolites are essential for plant fitness and human health, with their biosynthesis pathways tightly regulated at multiple levels. However, the translational regulation of their biosynthesis remains poorly understood. Here, we reveal a 5′ untranslated region (5′UTR)–mediated translational mechanism that controls glucosinolate production in Arabidopsis . A forward genetic screen exploring the metabolic interaction between auxin and glucosinolates identified two dominant Arabidopsis alleles, each carrying a single-nucleotide substitution located 13–base pair apart within the 5′UTR of MYB28 , a master regulator of aliphatic glucosinolate biosynthesis. These mutations markedly increase MYB28 protein abundance without affecting transcript levels, leading to enhanced glucosinolate production. Mutational profiling of the 5′UTR revealed that alterations in RNA tertiary structure influence translation efficiency, establishing a link between RNA conformation and metabolic output. Our findings uncover a previously uncharacterized layer of posttranscriptional regulation in plant-specialized metabolism and highlight the 5′UTR as a potential target for precision breeding to enhance crop performance and nutritional quality.

Histone acetylation shapes transcriptional programs during environmental stress. The Arabidopsis histone acetyltransferase GCN5/HAG1 , a catalytic subunit of the SAGA complex, has been implicated in salt stress responses and cell wall integrity. Here, we show that loss of GCN5 enhances reactive oxygen species (ROS) accumulation under NaCl stress and is accompanied by altered expression of class III peroxidase genes, with strong salt-induced upregulation of PRX71 and elevated basal PRX33 transcript abundance. Consistent with a role for these peroxidases in stress-associated cell wall remodeling, overexpression of PRX71 or PRX33 in the wild-type is sufficient to promote ectopic lignin deposition in roots. Conversely, prx71 and prx33 mutants show improved growth under salt stress and on the cellulose biosynthesis inhibitor isoxaben, and they lack the pronounced ectopic root lignification observed in gcn5 under salt stress. Chromatin immunoprecipitation followed by qPCR (ChIP-qPCR) reveals reduced H3K9 acetylation at PRX71 and PRX33 promoter regions in gcn5 compared with the wild-type, and reduced transcript abundance of candidate upstream transcription factors (TFs), including GATA21 and MYBS2 , accompanied by reduced H3K9ac at their loci. Together, our results support a model in which GCN5 constrains PRX71/PRX33 -mediated lignification during stress, likely through an indirect regulatory route that integrates chromatin state and transcription factor activity to limit stress-associated lignification while maintaining root growth under salt stress.

Iron (Fe) deficiency is a major yield-limiting factor in peanut (Arachis hypogaea L.) production because Fe availability is often low in agricultural soils. Although Fe is abundant in the Earth’s crust, only a small fraction remains soluble and available for plant uptake. In coarse-textured sandy soils with low buffering capacity, maintaining adequate Fe availability throughout the growing season is particularly difficult. Inorganic Fe fertilizers, such as iron sulfate, tend to precipitate rapidly under these conditions and become unavailable shortly after application. Therefore, synthetic Fe chelates are required to maintain Fe in solution and improve plant availability. Among these, Fe-EDDHA was selected for this study because of its high stability across a wide soil pH and its ability to retain soluble Fe in the soil solution. This study evaluated the effects of Fe-EDDHA application method, including in-furrow, banding, and foliar spray, and application rate on peanut pod yield, soil Fe dynamics, and plant tissue nutrient concentrations in sandy soils. A three-year field study was conducted in North Florida during 2022, 2024, and 2025. The highest pod yield, approximately 2,850 kg hm-2, was obtained with the in-furrow application of 5.60 kg hm-2. Kernel quality parameters were not affected by treatment but were significantly influenced by year. Pod yield in 2024 was lower than in the other years, at approximately 2,000 kg hm-2, likely due to less favorable field conditions. Soil Fe concentration was influenced by treatment in all years, with banded and foliar applications resulting in lower residual soil Fe, suggesting greater plant uptake. Tissue Fe concentration was not affected by treatment in 2022 but showed significant time-dependent treatment differences in 2024. Overall, the in-furrow method was most effective for maximizing pod yield, whereas foliar spray at 2.80 kg hm-2 was most effective for maintaining higher leaf Fe concentration during the season.