TCP transcription factors are a unique transcription family in higher plants, and play important roles in plant development, responses to environmental stresses and phytohormones. Radish is an important crop and widely cultivated worldwide. However, genome-wide identification and expression analysis of TCP family in radish has not been reported yet. In this study, 32 RsTCP genes were identified from the whole genome. Phylogenetic analysis showed that the RsTCP family can be divided into two major groups and three subgroups, namely Class I (PCF), Class II (CIN), and Class II (CYC/TB1). Chromosome mapping showed that 32 genes were distributed on all nine chromosomes of radish. Transcriptome data indicated that the transcription of RsTCP genes differed between tissues and developmental stages. Multiple phytohormone-related cis-acting elements in the promoter region of RsTCPs and several post-translational modification sites in RsTCP protein sequences were identified. The real-time quantitative PCR (RT-qPCR) analysis indicated that several RsTCP genes changed significantly in response to the treatments, including low temperature, drought, salt, gibberellin (GA₃), and abscisic acid. Among them, RsTCP16 showed significantly higher levels in leaves than in other radish tissues, and the transcription of RsTCP16 was significantly upregulated under the five treatments, especially during low temperature, salt shock, and GA₃ response, suggesting that RsTCP16 could be involved in the development of radish leaves and the response to stress. In summary, these results provided a basis for further exploring the molecular mechanism of RsTCP genes in radish.

Radish is an important root vegetable that is widely grown in Asia. The root-knot nematode (RKN) Meloidogyne incognita seriously affects the growth and development of radish root and causes poor appearance quality. However, the molecular mechanism of radish response to RKNs remains poorly understood. In this study, a total of 220 lncRNAs, 1144 mRNAs, 20 miRNAs and 153 proteins were differential expressed between the RKN-infected and WT samples. Correlation analysis of all DEPs compared with all DGEs showed that 8 mRNAs-DEPs showed a changed abundance. The results showed that 18 DEmiRNAs have 167 target DEGs in 220 miRNA-target modules and 29 DElncRNAs were predicted as putative targets of 16 DEmiRNAs in 37 miRNA-target modules. In all, 6 DGEs in the ABA pathway and 2 DGEs in the JA pathway were identified under RKN infection, respectively. The four regulatory networks of lncRNA-miRNA-mRNA were constructed in response to RKN infection. qRT-PCR analysis found that the expression pattern of 6 DElncRNAs, 6 DEmRNAs, 6 DEmiRNAs and 6 DEPs were consistent with sequencing results. These results provide a theoretical basis for studying the molecular mechanism of radish in response to M. incognita and breeding resistant varieties to this nematode.

Potato is an important crop in the world and is rich in various nutrients. Common tetraploid potato is not tolerant of low temperatures and frost. Low-temperature stress severely affects the growth above-ground and the yield underground in potato. The BBX genes play an important role in the plant response to low-temperature stress. However, the molecular mechanism underlying the potato StBBX genes involved in cold stress response remains unclear. In the present study, 30 StBBX genes were identified in potato and divided into five groups. A total of 10 motifs and 10 cis-acting elements were obtained in all BBX proteins. All StBBX genes contained light responsive elements in the promoter, of which nine StBBX genes harbored low-temperature responsive elements. In total, 15 pairs of StBBX genes were identified in duplicated genomic regions. The gene expression patterns of all StBBXs were assessed in different tissues by transcriptome data. The qRT-PCR analysis indicated that six StBBX genes were significantly induced in response to cold stress. Subcellular localization suggested that the StBBX17 protein was localized in the nucleus. Compared with wild type (WT), the cold tolerance in StBBX17 overexpression lines was dramatically increased. After cold treatment, the StBBX17 overexpression lines displayed a less injured area of leaves and lower electrolyte leakage compared with the WT plants, demonstrating StBBX17 positively regulated cold tolerances in potato. These results indicate that StBBX genes have important functions under cold stress, providing a theoretical reference for the breeding of cold-resistant potato.

Soluble sugar content is a key determinant of taste and flavor in radish taproots, particularly differences in sucrose content. To elucidate the regulatory mechanisms underlying sucrose accumulation in radish taproots, targeted sugar metabolomics and transcriptome analyses were performed using 'QX' (high soluble sugar and high sucrose content) and 'HG' (low soluble sugar and low sucrose content) at the mature taproot stage (90 days after sowing). Targeted metabolomics analysis identified a total of eight differentially expressed metabolites (DEMs), including five upregulated and three downregulated metabolites. Transcriptome analysis revealed 5265 upregulated genes and 5539 downregulated genes. RT-qPCR analysis displayed that there were multiple differentially expressed pivotal genes and transcription factors of sucrose metabolism. Integrated multi-omics analysis indicated that differentially expressed genes (DEGs) were predominantly enriched in fructose and mannose metabolism, galactose metabolism, and starch and sucrose metabolism pathways. Further yeast one-hybrid screening demonstrated that the RsNF-YA6 specifically binds to RsSUS2. Dual-luciferase reporter assays indicated that RsNF-YA6 significantly suppressed RsSUS2 expression, confirming its role as a negative regulatory transcription factor localized in the nucleus. The overexpression of RsNF-YA6 in Arabidopsis and radish led to a remarkable elevation in sucrose content. Collectively, these results reveal the regulatory function of the RsNF-YA6-RsSUS2 module in radish sucrose metabolism, offer novel insights into the molecular mechanisms underlying sucrose accumulation in radish taproots, and provide important genetic resources and a theoretical basis for breeding high-sucrose radish varieties.