Omics Analysis Unveils the Pathway Involved in the Anthocyanin Biosynthesis in Tomato Seedling and Fruits

Advancing vegetable genetics with gene editing: a pathway to food security and nutritional resilience in climate-shifted environments

As global populations grow and climate change increasingly disrupts agricultural systems, ensuring food security and nutritional resilience has become a critical challenge. In addition to grains and legumes, vegetables are very important for both human and animals because they contain vitamins, minerals, and fibre. Enhancing the ability of vegetables to withstand climate change threats is essential; however, traditional breeding methods face challenges due to the complexity of the genomic clonal multiplication process. In the postgenomic era, gene editing (GE) has emerged as a powerful tool for improving vegetables. GE can help to increase traits such as abiotic stress tolerance, herbicide tolerance, and disease resistance; improve agricultural productivity; and improve nutritional content and shelf-life by fine-tuning key genes. GE technologies such as Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9 (CRISPR-Cas9) have revolutionized vegetable breeding by enabling specific gene modifications in the genome. This review highlights recent advances in CRISPR-mediated editing across various vegetable species, highlighting successful modifications that increase their resilience to climatic stressors. Additionally, it explores the potential of GE to address malnutrition by increasing the nutrient content of vegetable crops, thereby contributing to public health and food system sustainability. Additionally, it addresses the implementation of GE-guided breeding strategies in agriculture, considering regulatory, ethical, and public acceptance issues. Enhancing vegetable genetics via GE may provide a reliable and nutritious food supply for an expanding global population under more unpredictable environmental circumstances.

SlAN2 overexpression improves cold resistance in tomato (Solanum lycopersicum L.) by regulating glycolysis and ascorbic acid metabolism

Chilling stress seriously affects the growth and yield of tomato. Anthocyanin is a typical chilling-induced metabolite with strong antioxidant activity and photoprotective capacity. Here, we found that anthocyanin was also involved in ascorbic acid biosynthesis and glycolysis under chilling stress. SlAN2 is an important positive gene in anthocyanin biosynthesis. The results of physiological indicators showed that SlAN2 overexpression lines (A189) had a greater ability to tolerate cold stress than wild-type (WT) plants. Conjoint analysis of transcriptomics and metabonomics of A189 lines and WT plants was used to analyze the metabolic difference and the cold resistance mechanisms caused by anthocyanin under chilling stress. The anthocyanin accumulated more in A189 than that in WT under chilling stress at 4 °C for 24 h, which led to hexoses and ascorbic acid increased significantly. Results indicate that SlAN2 overexpression reduces the expression of key enzyme genes in glycolytic pathway such as phosphofructokinase (PFK) and pyruvate kinase (PK) genes, weakens glycolysis ability, and promotes accumulation of hexoses in A189 lines at 4 °C for 24 h compared with wild lines. Additionally, ascorbic acid content is increased by up-regulated the genes of ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR). The increased hexose content can reduce cell osmotic potential, freezing point and synthesize more ascorbic acid, while the increased ascorbic acid content can enhance the ability to scavenge reactive oxygen species, so improves the cold resistance of tomato. The glycolysis and ascorbic acid metabolism pathway mediated by SlAN2 provides a new insight for the molecular mechanism of anthocyanins in improving the cold resistance of tomato and provides a new theoretical basis for cultivating new cold-tolerant tomato varieties.

Integration of comparative transcriptomics and WGCNA characterizes the regulation of anthocyanin biosynthesis in mung bean (Vigna radiata L.)

Mung bean is a dual-use crop widely cultivated in Southeast Asia as a food and medicine resource. The development of new functional mung bean varieties demands identifying new genes regulating anthocyanidin synthesis and investigating their molecular mechanism. In this study, we used high-throughput sequencing technology to generate transcriptome sequence of leaves, petioles, and hypocotyls for investigating the anthocyanins accumulation in common mung bean variety as well as anthocyanidin rich mung bean variety, and to elucidate their molecular mechanisms. 29 kinds of anthocyanin compounds were identified. Most of the anthocyanin components contents were significantly higher in ZL23 compare with AL12. Transcriptome analysis suggested that a total of 93 structural genes encoding the anthocyanin biosynthetic pathway and 273 regulatory genes encoding the ternary complex of MYB-bHLH-WD40 were identified, of which 26 and 78 were differentially expressed in the two varieties. Weighted gene co-expression network analysis revealed that VrMYB3 and VrMYB90 might have enhanced mung bean anthocyanin content by inducing the expression of structural genes such as PAL, 4CL, F3'5'H, LDOX, and F3'H, which was consistent with qRT-PCR results. These findings are envisaged to provide a reference for studying the molecular mechanism of anthocyanin accumulation in mung beans.