Pepper, as a vegetable crop with a wide cultivation area worldwide, besides being a significant condiment and food, also has a momentous use for chemistry, medicine, and other industries. Pepper fruits are rich in various pigments, such as chlorophyll, carotenoids, anthocyanins, and capsanthin, which have important healthcare and economic value. Since various pigments are continuously metabolized during the development of pepper fruits, peppers exhibit an abundant fruit-colored phenotype in both the mature and immature periods. In recent years, great progress has been made in the study of pepper fruit color development, but the developmental mechanisms are still unclear systematically dissected in terms of pigment, biosynthesis, and regulatory genes. The article outlines the biosynthetic pathways of three important pigments: chlorophyll, anthocyanin, and carotenoid in pepper and the various enzymes involved in these pathways. The genetics and molecular regulation mechanisms of different fruit colors in immature and mature peppers were also systematically described. The objective of this review is to provide insights into the molecular mechanisms of pigments biosynthesis in pepper. This information will provide theoretical basis for the breeding of high-quality colored pepper varieties in the future.

Purple acid phosphatase (PAP) plays a vital role in plant phosphate acquisition and utilization, as well as cell wall synthesis and redox reactions. In this study, comprehensive comparative analyses of PAP genes were carried out using the integration of phylogeny, chromosomal localization, intron/exon structural characteristics, and expression profiling. It was shown that the number of introns of the PAP genes, which were distributed unevenly on 12 chromosomes, ranged from 1 to 12. These findings pointed to the existence of complex structures. Phylogenetic analyses revealed that PAPs from tomato, rice, and Arabidopsis could be divided into three groups (Groups I, II, and III). It was assumed that the diversity of these PAP genes occurred before the monocot–dicot split. RNA-seq analysis revealed that most of the genes were expressed in all of the tissues analyzed, with the exception of SlPAP02, SlPAP11, and SlPAP14, which were not detected. It was also found that expression levels of most of the SlPAP gene family of members were changed under phosphorus stress conditions, suggesting potential functional diversification. The findings of this work will help us to achieve a better insight into the function of SlPAP genes in the future, as well as enhance our understanding of their evolutionary relationships in plants.

The Solanaceae family, which includes vital crops such as tomatoes, peppers, eggplants, and potatoes, is increasingly impacted by drought due to climate change. Recent research has concentrated on unraveling the molecular mechanisms behind drought resistance in these crops, with a focus on abscisic acid (ABA) signaling pathways, transcription factors (TFs) like MYB (Myeloblastosis), WRKY (WRKY DNA-binding protein), and NAC (NAM, ATAF1/2, and CUC2- NAM: No Apical Meristem, ATAF1/2, and CUC2: Cup-shaped Cotyledon), and the omics approaches. Moreover, transcriptome sequencing (RNA-seq) has been instrumental in identifying differentially expressed genes (DEGs) crucial for drought adaptation. Proteomics studies further reveal changes in protein expression under drought conditions, elucidating stress response mechanisms. Additionally, microRNAs (miRNAs) have been identified as key regulators in drought response. Advances in proteomics and transcriptomics have highlighted key proteins and genes that respond to drought stress, offering new insights into drought tolerance. To address the challenge of drought, future research should emphasize the development of drought-resistant varieties through precision breeding techniques such as gene editing, marker-assisted selection (MAS), and the integration of artificial intelligence. Additionally, the adoption of environmentally sustainable cultivation practices, including precision irrigation and the use of anti-drought agents, is crucial for improving water-use efficiency and crop resilience. International collaboration and data sharing will be essential to accelerate progress and ensure global food security in increasingly arid conditions. These efforts will enable Solanaceae crops to adapt the challenges posed by climate change, ensuring their productivity and sustainability.