Cucumber is one of the most widely grown vegetables in China and an indispensable fresh fruit in the diet. With the development of society, the demand of people for cucumber quality is higher and higher. Therefore, cultivating high-quality cucumber varieties is one of the main goals of cucumber breeding. With the rapid development of biotechnology such as molecular marker, cucumber quality control network is becoming clear. In this review, we describe the formation mechanism of cucumber fruit quality from three aspects: (1) the commercial quality of cucumber fruit, (2) nutritional quality formation, and (3) flavor quality of cucumber fruit. In addition, the determinants of cucumber fruit quality were summarized from two aspects of genetic regulation and cultivation methods in order to provide ideas for cucumber researchers and cultivators to improve fruit quality.

Citrus reticulata ‘Chachi’ (CRC) has long been recognized for its nutritional benefits, health-promoting properties, and pharmacological potential. Despite its importance, the bioactive components of CRC and their biosynthetic pathways have remained largely unexplored. In this study, we introduce a gap-free genome assembly for CRC, which has a size of 312.97 Mb and a contig N50 size of 32.18 Mb. We identified key structural genes, transcription factors, and metabolites crucial to flavonoid biosynthesis through genomic, transcriptomic, and metabolomic analyses. Our analyses reveal that 409 flavonoid metabolites, accounting for 83.30% of the total identified, are highly concentrated in the early stage of fruit development. This concentration decreases as the fruit develops, with a notable decline in compounds such as hesperetin, naringin, and most polymethoxyflavones observed in later fruit development stages. Additionally, we have examined the expression of 21 structural genes within the flavonoid biosynthetic pathway, and found a significant reduction in the expression levels of key genes including 4CL, CHS, CHI, FLS, F3H, and 4′OMT during fruit development, aligning with the trend of flavonoid metabolite accumulation. In conclusion, this study offers deep insights into the genomic evolution, biosynthesis processes, and the nutritional and medicinal properties of CRC, which lay a solid foundation for further gene function studies and germplasm improvement in citrus.

Increased consumption of vegetables has been recommended worldwide as a part of a healthy diet; therefore, determining gene function among breeding materials is crucial for vegetable improvement to meet the sustainable development of new vegetable varieties. However, genetic transformation is time-consuming and laborious, which limits the exploration of gene function for various vegetable crops. Virus-Induced Gene Silencing (VIGS) can perform large-scale and rapid gene silencing in plants due to a reduction in the experimental period and its independence from the stable genetic transformation, providing an excellent opportunity for functional research. VIGS can accelerate model plant research and make it easier to analyze gene function and validation in vegetable crops. Moreover, with the advent of technologies such as virus-mediated heterologous protein expression and the development of CRISPR/Cas9 technology, virus-mediated genetic tools have ushered in a new era in genetics and crop improvement. This study summarizes recent achievements in VIGS and Virus-Induced Gene Editing (VIGE) in vegetables. We also identify several challenges in the current state of VIGS technology in vegetables, serving as a guide for future research.

Peony is a traditional Chinese flower with significant ornamental and medicinal value. However, there are still problems, such as serious browning, difficulties in differentiation, and rooting and low regeneration efficiency in the process of the regeneration system established, which have hindered the development of transgenic peony technology. Establishing an efficient regeneration system is considered to be an important goal among peony researchers. Here, we describe a protocol for high-frequency callus induction and establishment of peony plants using flower petals as explants. Murashige and Skoog (MS) medium supplemented with 2.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), 1.5 mg/L N-(phenylmethyl)-9H-purin-6-amine (6-BA), and 0.3 mg/L 1-naphthylacetic acid (NAA) was identified as the best medium for callus induction, achieving an induction rate of up to 98.52%. The highest peony proliferation rate (234%) was achieved on MS supplemented with 0.2 mg/L NAA and 3.0 mg/L 6-BA. The highest callus differentiation rate (34.81%) was achieved on MS supplemented with 2.0 mg/L 6-BA and 0.5 mg/L zeatin (ZT). The highest rooting rate was 23.33% when using 1/2 MS supplemented with 0.1 mg/L NAA and 0.05 mg/L 3-indolebutyric acid (IBA). After acclimation, the plants were transferred to pots, where they showed robust growth. We also observed the surface structures of the calluses using scanning electron microscopy and found that the differentiation characteristics of the calluses were hugely variable and that different surface structures appeared to affect bud differentiation efficiency. The efficient and rapid system for regenerating peonies using petal cultures established here will create new opportunities for the mass reproduction and genetic engineering of peony plants.

Polygalacturonase-inhibiting protein (PGIP) is an important plant biochemical anti-disease factor. PGIP has a leucine-rich repeat structure that can selectively bind and inhibit the activity of endo-polygalacturonase (endo-PG) in fungi, playing a key role in plant disease resistance. The regulation of PGIP in plant disease resistance has been well studied, and the effect of PGIP to increase disease resistance is clear. This review summarizes recent advances in understanding the PGIP protein structure, the PGIP mechanism of plant disease resistance, and anti-disease activity by PGIP gene transfer. This overview should contribute to a better understanding of PGIP function and can help guide resistance breeding of PGIP for anti-disease effects.