Pepper (Capsicum annuum L.) represents a highly significant agricultural commodity worldwide. Heat stress (HS) poses a severe threat to pepper productivity and quality. However, our understanding of the molecular alterations triggered by HS remains insufficient. This study focused on characterizing P19055 and P17087 as heat-tolerant and heat-sensitive pepper lines, respectively. Through RNA sequencing, we quantified transcript abundance in pepper fruit to investigate the impact of HS on gene expression. A total of 41,793 differentially expressed genes (DEGs) was identified, encompassing 33,703 known genes and 8090 novel genes. Additionally, we obtained 89,821 expressed transcripts, including 52,726 known transcripts and 37,095 new transcripts. By comparing gene expression levels between P17087 and P19055 fruit, we pinpointed 2324 genes exhibiting differential expression across three time points (0.5 h, 2 h, 6 h). Leveraging the weighted correlation network analysis (WGCNA) approach, we constructed a co-expression network of DEGs in P19055 and P17087 based on transcriptomic data acquired at these time points. Notably, nineteen modules displayed significant correlations with the time points following HS during the fruiting stage in both genotypes. Functional enrichment analysis revealed that the DEGs were primarily associated with metabolic and cellular processes in response to stress, particularly photosynthesis at the 2 h and 6 h time points. Moreover, we identified and categorized 26 families of transcription factors, including ERF (19), WRKY (12), MYB (15), NAC (7), bHLH (7), MIKC (7), GRAS (6), and 40 others, which may potentially regulate the expression of key genes in response to HS. Our findings contribute to a comprehensive understanding of the molecular mechanisms governing HS during the fruiting stage of pepper cultivation.

Cytoplasmic male-sterility (CMS) is important for the utilization of crop heterosis and study of the molecular mechanisms involved in CMS could improve breeding programs. In the present study, anthers of the pepper CMS line HZ1A and its maintainer line HZ1B were collected from stages S1, S2, and S3 for transcriptome sequencing. A total of 47.95 million clean reads were obtained, and the reads were assembled into 31,603 unigenes. We obtained 42 (27 up-regulated and 15 down-regulated), 691 (346 up-regulated and 345 down-regulated), and 709 (281 up-regulated and 428 down-regulated) differentially expressed genes (DEGs) in stages S1, S2, and S3, respectively. Through Gene Ontology (GO) analysis, the DEGs were found to be composed of 46 functional groups. Two GO terms involved in photosynthesis, photosynthesis (GO:0015986) and photosystem I (GO:0009522), may be related to CMS. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, oxidative phosphorylation (ko00190) and phenylpropanoid biosynthesis (ko00940) were significantly enriched in the S1 and S2 stages, respectively. Through the analysis of 104 lipid metabolism-related DEGs, four significantly enriched KEGG pathways may help to regulate male sterility during anther development. The mitochondrial genes orf470 and atp6 were identified as candidate genes of male sterility for the CMS line HZ1A. Overall, the results will provide insights into the molecular mechanisms of pepper CMS.

Peel glossiness is an important commercial trait of eggplant (Solanum melongena L.). In this study, two eggplant-inbred lines with different levels of peel glossiness were used to identify genes related to peel glossiness. Paraffin section analysis showed that increased wax thickness and wrinkles on the wax surface of eggplant peels decreased glossiness. Differential gene expression related to eggplant peel glossiness was analyzed by comparing the transcriptomes of eggplant peels with different gloss levels and at different developmental stages. The results identified 996 differentially expressed genes (DEGs), including 502 upregulated and 494 downregulated genes, possibly related to eggplant peel glossiness. GO enrichment and KEGG enrichment analyses revealed that the DNA replication pathway (GO:0003688, GO:0006270) and the photosynthesis pathway (map00195) were downregulated and thus may be associated with reduced eggplant peel glossiness. Expression level analysis of eggplant peels with different glossiness levels revealed that a C2H2 transcription factor gene, two ERF transcription factor genes, one long-chain acyl-CoA synthetase gene, and four wax- or cutin-related genes may be associated with the glossiness of eggplant fruit peels. These findings will help guide future genetic improvements in eggplant peel glossiness.

Pepper is an important and widely cultivated economic vegetable in the world (Yin et al., 2021). In June 2021, approximately 25% to 33.3% of the pepper plants had rot disease symptoms in Zhuanghang...

Eggplant cultivation faces major challenges from continuous cropping obstacles, which degrade soil health and limit sustainable production. Microbial inoculants offer a promising strategy for addressing such issues by modifying the soil environment and rhizosphere ecology. In this study, a field experiment was conducted to evaluate the effects of three bacterial inoculants, including Bacillus zhangzhouensis (BF1), Bacillus mobilis (BF2), and Zhihengliuella halotolerans (BF3), on soil properties, microbial community structure, and crop performance in a continuously cropped eggplant system. The results showed that three inoculants exerted strain-specific effects: BF1 significantly promoted eggplant vegetative growth and yield, increasing plant height by 32.1%, stem diameter by 28.7%, and total yield by 142.4% relative to the control; BF3 selectively improved fruit quality and soil nutrient status, elevating eggplant fruit total amino acid, soluble protein, and soluble sugar contents by 68.9%, 52.3%, and 41.2%, respectively, and increasing soil organic carbon (SOC), total nitrogen (TN), and available nitrogen (AN) by 13.73%, 18.03%, and 84.92% compared with the control. BF2 showed limited efficacy relative to the control. All inoculants enhanced the abundance of beneficial bacteria and reshaped the rhizosphere microbial community structure. The findings demonstrate the potential of strain-specific microbial inoculants to alleviate continuous cropping obstacles and promote sustainable eggplant production.

Modulating nutrient-solution electrical conductivity (EC) is an important strategy for improving the fruit flavor of tomato (Solanum lycopersicum L.) in soilless culture. Previous salinity studies have typically elevated EC through NaCl supplementation, which is physiologically distinct from raising EC via basal nutrient concentrations. Moreover, whether the quality-improving effect of moderately high electrical conductivity (HEC) arises from passive osmotic concentration or active metabolic reprogramming remains unclear. Tomato cultivar ‘Hangza 602’ was grown under CK (2.0 mS cm⁻¹) and HEC (3.0 mS cm⁻¹). Fruits were sampled at mature-green, breaker, pink and red-ripe stages for integrated transcriptomic, enzymatic and metabolomic analyses. HEC increased total soluble solids across ripening stages and promoted sugar and organic acid accumulation at pink and red-ripe stages, with a greater organic-acid increment reducing the sugar–acid ratio. Sugar transporter genes were induced at the breaker stage. At the pink stage, HEC elevated the activities of phosphofructokinase, citrate synthase and NADP–malate dehydrogenase without altering sucrose-phosphate synthase, indicating enhanced catabolic flux rather than sucrose biosynthesis. Sugars and citric acid accumulated persistently, whereas malic acid rose transiently then declined at red-ripe. Multiple downstream pathways were altered in HEC-treated red-ripe fruits. Collectively, HEC initiates stage-specific carbon-metabolic reprogramming combining osmotic and active effects, providing experimental insights for precision EC management in protected tomato production. Future work will further identify key regulatory genes governing this stage-specific metabolic response and validate the combined effects of EC and other environmental factors to develop robust soilless culture strategies for flavor improvement.