Gray mold caused by Botrytis cinerea, a necrotrophic plant pathogen, is one of the most damaging diseases of tomato, resulting in both pre- and post-harvest losses. (E)-2-Hexenal dose-dependently inhibited the mycelial growth of B. cinerea, and caused distortion of mycelia and loss of the cytoplasm content, thus altering the morphology of B. cinerea hyphae. To understand molecular processes in response to (E)-2-hexenal, transcriptome sequencing was carried out using RNA-Seq technology. RNA-Seq results revealed that a total of 3,893 genes were differentially expressed in B. cinerea samples treated with (E)-2-hexenal fumigation. Among these genes, 1,949 were upregulated and 1,944 were downregulated. Moreover, further analysis results showed 2,113 unigenes were mapped onto 259 pathways in Kyoto Encyclopedia of Genes and Genomes (KEGG). Moreover, (E)-2-hexenal stress affected the expression of genes involved in the pathways of cell wall, cell membrane, and energy metabolism. KEGG pathway analysis showed that the terpenoid backbone biosynthesis and steroid biosynthesis were the most enriched in ergosterol biosynthetic process transcriptome data. Particularly, (E)-2-hexenal fumigation had influenced ergosterol biosynthetic gene expression levels (e.g., ERG1, ERG3, ERG4, ERG7, ERG12, ERG13, ERG24, ERG25, ERG26, and ERG27), which were in good agreement with the experimental measurement results, and the ergosterol content decreased. Collectively, the results of this study increase our current understanding of (E)-2-hexenal inhibition mechanisms in B. cinerea and provide relevant information on postharvest shelf life extension and preservation of fruits and vegetables.

Tomato is a widely cultivated fruit and vegetable and is valued for its flavor, colour, and nutritional value. C₆-aldehydes, such as (E)-2-hexenal, not only have antibacterial and antifungal properties but also function as signaling molecules that control the defense mechanisms of plants, including tomatoes. In this study, we used liquid chromatography-mass spectrometry (LC-MS) and RNA sequencing techniques to generate metabolome and transcriptome datasets that elucidate the molecular mechanisms regulating defense responses in tomato leaves exposed to (E)-2-hexenal. A total of 28.27 Gb of clean data were sequenced and assembled into 23,720 unigenes. In addition, a non-targeted metabolomics approach detected 739 metabolites. There were 233 significant differentially expressed genes (DEGs) (158 up-regulated, 75 down-regulated) and 154 differentially expressed metabolites (DEMs) (86 up-regulated, 69 down-regulated). Most nucleotides and amino acids (L-Phenylalanine, L-Asparagine, L-Histidine, L-Arginine, and L-Tyrosine) and their derivatives were enriched. The analyses revealed that mitogen-activated protein kinase (MPK), pathogenesis-related protein (PR), and endochitinase (CHIB) were primarily responsible for the adaptation of plant defense responses. Therefore, the extensive upregulation of these genes may be associated with the increased plant defense response. These findings help us comprehend the defense response of plants to (E)-2-hexenal and improve the resistance of horticultural plants.

The ATP binding cassette transporter (ABC) superfamilies consist of many membrane proteins and play a very important role in transmembrane transport of substances such as secondary metabolites, phytohormones, and heavy metals. However, it is still unknown what role the B subfamily of the ABC family (ABCB) plays in tomatoes. In the present study, we conducted a genome-wide analysis of the ABCB subfamily in tomato (Solanum lycopersicum), which is the largest group in the ABC family with 29 members, followed by the C subfamily. The predicted ABCB genes were distributed across 10 chromosomes, with up to six SlABCB genes emerging on chromosome 3 and one SlABCB gene detected on chromosome 4. The quantity and structure of exons and introns varied by gene. Analysis of the transcriptome data revealed increased transcript levels of ABCB subfamily genes following cadmium stress. Similarly, these results of quantitative real-time polymerase chain reaction (qRT-PCR) were also confirmed. A yeast experiment showed that the genes SlABCB8, SlABCB15, SlABCB22, and SlABCB26 can mediate Cd tolerance. Overall, our research offers new insight into the molecular function of ABCB subfamily transporter genes in S. lycopersicum, which is highly valuable and important because of the effect of long-term application of ABCB transporter genes on regulation under heavy metal stress.

In China, cadmium (Cd) contamination has turned into a primary environmental concerns in agricultural soils. This research surveyed the molecular mechanism of biochemical and physiological in response to Cd stress in tomato plants. Cadmium treatment prominently restrained tomato root growth (by 43.46%), and stimulated their antioxidant enzyme activities (POD and CAT). Cadmium treatment reduced their dry weight of shoot and root at day 7, by 40.42% and 60.40%, respectively. During the entire processing period, total chlorophyll contents were decreased and the malondialdehyde (MDA) content increased. A comparative transcriptome (RNA-Seq) was assembled de novo and differentially expressed genes (DEGs) were surveyed among 7-day-old tomato plants with or without cadmium ion treatment for 24 h. 18,883 unigenes in total were grouped into 51 Gene Ontology (GO) categories and 89 Kyoto Encyclopedia of Genes and Genomes terms (KEGG). There were 1,716 differentially expressed genes (DEGs), 559 down- and 1157 up-regulated genes. Go term enrichment analysis revealed that multiple phytohormone-related signaling pathway were significantly enriched in DEGs. Most genes involved in lignin biosynthesis pathway were up-regulated, for instance, COMT and CCOMT. Cd²⁺ is absorbed into tomato root cells to generate ROS and gives rise to oxidative stress. The essential hormones biosynthesis such as ethylene, IAA and JA should be stimulated to induce the activation of signal proteins. Our results provide the basis for further understanding of Cd tolerance mechanisms in plants.

Camellia oleifera Abel., an economically significant oil-producing crop widely cultivated in southern China, is renowned for its high-quality edible oil and diverse pharmacological activities. The plant is rich in terpenoids, particularly triterpenoid saponins, which contribute to its health-promoting properties. However, a comprehensive review summarizing the diversity, biological activities, biosynthesis, and regulatory mechanisms of terpenoids in C. oleifera is lacking. This review systematically categorizes terpenoids identified from different parts of C. oleifera, elucidates their structural features, and infers their biosynthetic pathways. The biological activities of terpenoid-rich extracts and individual compounds, including antioxidant, anti-inflammatory, anticancer, antimicrobial, and hypoglycemic effects, are discussed. Furthermore, the potential applications of C. oleifera terpenoids in functional foods, pharmaceuticals, and agriculture are explored. This review aims to provide a valuable reference for future research and utilization of C. oleifera terpenoids.