Chili pepper (Capsicum annuum L.) is extensively cultivated in China, with its production highly reliant on regional environmental conditions. Given ongoing climate change, it is imperative to assess its impact on chili pepper cultivation and identify suitable habitats for future cultivation. In this study, the MaxEnt model was optimized and utilized to predict suitable habitats for open-field chili pepper cultivation, and changes in these habitats were analyzed using ArcGIS v10.8. Our results showed that the parameter settings of the optimal model were FC = LQPTH and RM = 2.7, and the critical environmental variables influencing chili pepper distribution were annual mean temperature, isothermality, maximum temperature of the warmest month, and precipitation of the warmest quarter. Under current climate conditions, suitable habitats were distributed across all provinces in China, with moderately- and highly-suitable habitats concentrated in the east of the Qinghai–Tibetan Plateau and south of the Inner Mongolia Plateau. Under future climate scenarios, the area of suitable habitats was expected to be larger than the current ones, except for SSP126-2050s, and reached the maximum under SSP126-2090s. The overlapping suitable habitats were concentrated in the east of the Qinghai–Tibetan Plateau and south of the Inner Mongolia Plateau under various climate scenarios. In the 2050s, the centroids of suitable habitats were predicted to shift towards the southwest, except for SSP126, whereas this trend was reversed in the 2090s. Our results suggest that climate warming is conductive to the cultivation of chili pepper, and provide scientific guidance for the introduction and cultivation of chili pepper in the face of climate warming.

Global warming and waterlogging stress due to climate change are expected to continue influencing agricultural production worldwide. In the field, two or more environmental stresses usually happen simultaneously, inducing more complex responses in plants compared with individual stresses. Our aim was to clarify how the two key factors (temperature and water) interacted and influenced physiological response and plant growth in tomatoes under ambient temperature, moderately elevated temperature, waterlogging stress, and moderately elevated temperature and waterlogging stress. The results showed that leaf photosynthesis was inhibited by waterlogging stress but enhanced by elevated temperature, as shown by both the light- and temperature-response curves. The elevated temperature decreased leaf water-use efficiency, but enhanced plant growth and fresh and dry weights of plants under both normal water supply and waterlogging stress conditions. Elevated temperature generally decreased the anthocyanin and flavonol index in tomato leaves compared with the control temperature, regardless of water status. The increase in the optimal temperature was more pronounced in plants under normal irrigation than under waterlogging stress. Waterlogging stress significantly inhibited the root length, and leaf number and area, while the moderately elevated temperature significantly enhanced the leaf number and area. Overall, the moderately elevated temperature offset the effects of waterlogging stress on tomato plants, as shown by leaf gas exchange, plant size, and dry matter accumulation. Our study will improve the understanding of how tomatoes respond to increasing temperature and excess water.

The formation of fruit color in pepper is closely related to the processes of carotenoid metabolism. In this study, red wild-type pepper XHB, SP01, PC01 and their corresponding mutants H0809 (orange), SP02 (yellow), and PC02 (orange) were used as research materials. The Ggps, Psy, Lcyb, Crtz, Zep, and Ccs genes involved in carotenoid biosynthesis were cloned, and bioinformatics and expression analyses were carried out. The results showed that the full lengths of the six genes were 1110 bp, 2844 bp, 1497 bp, 2025 bp, 510 bp, and 1497 bp, and they encoded 369, 419, 498, 315, 169, and 498 amino acids, respectively. Except for the full-length Ccs gene, which could not be amplified in the yellow mutant SP02 and the orange mutant PC02, the complete full-length sequences of the other genes could be amplified in different materials, indicating that the formation of fruit color in the SP02 and PC02 mutants could be closely related to the deletion or mutation of the Ccs gene. The analytical results of real-time quantitative reverse transcription PCR (qRT-PCR) showed that the Ggps, Psy, Lcyb, Crtz, and Zep genes were expressed at different developmental stages of three pairs of mature-fruit-colored materials, but their patterns of expression were not consistent. The orange mutant H0809 could be amplified to the full Ccs gene sequence, but its expression was maintained at a lower level. It showed a significant difference in expression compared with the wild-type XHB, indicating that the formation of orange mutant H0809 fruit color could be closely related to the different regulatory pattern of Ccs expression. The results provide a theoretical basis for in-depth understanding of the molecular regulatory mechanism of the formation of color in pepper fruit.

Our multi-omics investigation of pepper fruit coloration dynamics demonstrates that the coordinated regulation of flavonoid accumulation and chlorophyll retention underpins the distinct pigmentation patterns between dark green (XHB) and light green (QL2017) cultivars. Through the integrated analysis of three developmental stages (10–30 DPA), we identified 989 differentially accumulated metabolites (DAMs) and 810 differentially expressed genes (DEGs), with flavonoid biosynthesis, phenylpropanoid metabolism, and chlorophyll turnover pathways pinpointed as central regulatory hubs. Notably, key metabolites such as quercitrin, kaempferol-3-O-rhamnoside, and cinnamic acid were significantly enriched in dark green fruits (XHB), coinciding with enhanced antioxidant activity and delayed chlorophyll degradation. Transcriptomic data revealed the coordinated upregulation of chlorophyll biosynthesis genes (COX15, POR) and light-harvesting complex components (Lhcb1, Lhcb2), while PAO—a pivotal chlorophyll catabolism gene—also exhibited elevated expression. Co-expression network analysis highlighted scopoletin GTase, F5H, CCR, and CAD as hub genes regulating flavonoid biosynthesis. qRT-PCR validation confirmed high consistency with transcriptomic trends (r > 0.85, p < 0.01). Our findings propose a synergistic model wherein flavonoid accumulation and chlorophyll metabolic dynamics jointly orchestrate green fruit pigmentation, offering novel insights and molecular targets for the precision breeding of pepper fruit coloration.

Tomato fruit malformation causes substantial yield and economic losses, but its molecular mechanisms are not well understood. This study compared floral traits of WT ‘QT57’ and malformed-fruit mutant ‘QT2’, integrated transcriptomic data, and qRT-PCR analysis to screen key candidate genes, and analyzed the pectinase gene family. The results found the ‘QT2’ mutant differed from WT ‘QT57’ in flower and fruit development. Expression analysis of CLAVATA-WUSCHEL pathway genes preliminarily validated the compensatory mechanism of SlCRCa and SlCRCb in ‘QT2’ malformed fruit. Six pectinase genes were identified as key candidates via RNA-seq and qRT-PCR analysis. Transcriptomic and qRT-PCR analyses of the pectinase gene family revealed their potential role in regulating tomato fruit malformation. Family analysis showed 34 pectinase genes distributed unevenly across 12 chromosomes. Subcellular localization confirmed SlPL7 in the nucleus and SlPME9 in the cell membrane/endoplasmic reticulum. The PL and PME genes were evolutionarily close, suggesting a potential functional overlap. Gibberellin-responsive elements were found in most pectinase genes. Pectinase genes may regulate tomato fruit malformation through the gibberellin-WUS pathway, carbohydrate metabolism, or cell wall metabolic disorder. This pathway provides new targets gene for the precise regulation of fruit malformation and offers significant reference value for practical production.

In cabbage, epidermal wax plays a key role in adaptation to abiotic and biotic stresses. The glossy green cabbage variety, which has less wax, is becoming increasingly popular on the market. In this study, the highly inbred waxy cabbage HQ2-1 and the glossy green cabbage Y2-1 were sampled for fine mapping and transcriptomics analysis. In the glossy green leaf cabbage, inheritance follows a simple dominant pattern. BSA-seq and interval targeted sequencing technology identified BoCER1 as the candidate gene controlling the leaf wax trait in Brassica oleracea. Downregulated genes in the α-linolenic acid metabolic pathway and upregulated genes in the wax synthesis pathway in HQ2-1 collectively promote wax formation in HQ2-1 leaves. Cold stress induced the upregulation of α-linolenic acid metabolic pathway genes in HQ2-1, and we speculate that the upregulation of these genes may promote jasmonic acid accumulation. Our study lays a solid foundation for further understanding the regulatory mechanism of leaf wax formation in cabbage and for the translational application of breeding new glossy cabbage varieties.