The NBS-LRR (NLR) gene family plays a pivotal role in regulating disease defense response in plants. Cucumber is one of the most important vegetable crops in the world, and various plant diseases, including powdery mildew (PM), cause severe losses in both cucumber productivity and quality annually. To characterize and understand the role of the CC-NBS-LRR(CNL) family of genes in disease defense response in cucumber plants, we performed bioinformatical analysis to characterize these genes systematically. We identified 33 members of the CNL gene family in cucumber plants, and they are distributed on each chromosome with chromosome 4 harboring the largest cluster of five different genes. The corresponding CNL family member varies in the number of amino acids and exons, molecular weight, theoretical isoelectric point (pI) and subcellular localization. Cis-acting element analysis of the CNL genes reveals the presence of multiple phytohormone, abiotic and biotic responsive elements in their promoters, suggesting that these genes might be responsive to plant hormones and stress. Phylogenetic and synteny analysis indicated that the CNL proteins are conserved evolutionarily in different plant species, and they can be divided into four subfamilies based on their conserved domains. MEME analysis and multiple sequence alignment showed that conserved motifs exist in the sequence of CNLs. Further DNA sequence analysis suggests that CsCNL genes might be subject to the regulation of different miRNAs upon PM infection. By mining available RNA-seq data followed by real-time quantitative PCR (qRT-PCR) analysis, we characterized expression patterns of the CNL genes, and found that those genes exhibit a temporospatial expression pattern, and their expression is also responsive to PM infection, ethylene, salicylic acid, and methyl jasmonate treatment in cucumber plants. Finally, the CNL genes targeted by miRNAs were predicted in cucumber plants. Our results in this study provided some basic information for further study of the functions of the CNL gene family in cucumber plants.

The ABCG is the largest subfamily of the ABC family with extensive functions, and only a few members have been identified in detail. However, more and more studies have shown that the members of this family are very important and are involved in many life processes such as plant development and response to various stresses. Cucumber is an important vegetable crops around the world. The cucumber development is essential for its production and quality. Meanwhile, various stresses have caused serious losses of cucumber. However, the ABCG genes were not well characterized and functioned in cucumber. In this study, the cucumber CsABCG gene family were identified and characterized, and their evolutionary relationship and functions were analyzed. The cis-acting elements and expression analysis showed that they played important role in development and responding to various biotic and abiotic stresses in cucumber. Phylogenetic analysis, sequence alignment and MEME (Multiple Em for Motif Elicitation) analysis indicated that the functions of ABCG proteins in different plants are evolutionarily conserved. Collinear analysis revealed that the ABCG gene family was highly conserved during the evolution. In addition, the potential binding sites of the CsABCG genes targeted by miRNA were predicted. These results will lay a foundation for further research on the function of the CsABCG genes in cucumber.

Flavonoids are essential secondary metabolites in plants, predominantly found in flowers, leaves, and fruits. They mainly include anthocyanins, proanthocyanidins, and flavonols. Transcription factors are a crucial family of proteins in plants, playing a significant role in regulating the biosynthesis of secondary metabolites. This review introduces flavonoids and explores the characteristics and biological functions of MYB transcription factors. It establishes a phylogenetic tree using Arabidopsis thaliana MYB transcription factors as an example, which includes 17 subgroups (S1–S17). The subgroups related to flavonoids are primarily concentrated in S17, further classified into A, C, D, E, and F. The review also discusses the different regulatory roles of MYB transcription factors in flavonoid synthesis in monocotyledonous and dicotyledonous plants. This knowledge provides a theoretical foundation for further studies on the diverse regulatory functions of MYB transcription factors in flavonoid biosynthesis across the plant kingdom.

Advances in genomics, genetics, and breeding of the cucurbit plant Cucurbits, the second largest vegetable family, encompass a wide variety of vegetables such as watermelon, melon, pumpkin, cucumber, bitter melon, bitter gourd, wax gourd, and numerous other species. The importance of cucurbit crops as a food source is recognized worldwide, and researchers have consistently focused on improving their quality and stress resistance. Firstly, as people's living standards improve, there is a growing demand for high-quality cucurbits, which in turn requires the cultivation of new and improved germplasms. Secondly, the detrimental effects of various biotic and abiotic stresses significantly impact the yield and food safety of cucurbit crops. Therefore, studying the stress resistance of cucurbit crops is crucial for ensuring safe and efficient production. By investigating the traits related to quality and stress resistance in cucurbit crops, valuable theoretical support can be provided for the development of innovative germplasms. In recent years, significant progress has been made in the genomics of cucurbit crops, including cucumber, melon, and watermelon (http://cucurbitgenomics.org/). This has led to rapid development in the genetics of these crops. High-density genetic maps have been established, and there has been great progress in map-based cloning of desirable traits. Additionally, the completion of genome sequencing has facilitated molecular biology research using omics methods such as genome sequencing and transcriptome sequencing (http://cucurbitgenomics.org/). These advancements have provided convenience for studying the genetics and molecular biology of agronomic traits in cucurbit crops, ultimately benefiting their genetic breeding. The purpose of this topic is to highlight the progress made in genomics, genetics, and breeding of cucurbit crops, with the aim of establishing a solid foundation for breeding desirable traits in these crops.