Chitinases are of great importance in chitin degradation and remodeling in insects. However, the genome-wide distribution of chitinase-like gene family in Bemsia tabaci, a destructive pest worldwide, is still elusive. With the help of bioinformatics, we annotated 14 genes that encode putative chitinase-like proteins, including ten chitinases (Cht), three imaginal disk growth factors (IDGF), and one endo-β-N-acetylglucosaminidase (ENGase) in the genome of the whitefly, B. tabaci. These genes were phylogenetically grouped into eight clades, among which 13 genes were classified in the glycoside hydrolase family 18 groups and one in the ENGase group. Afterwards, developmental expression analysis suggested that BtCht10, BtCht5, and BtCht7 were highly expressed in nymphal stages and exhibit similar expression patterns, implying their underlying role in nymph ecdysis. Notably, nymphs exhibited a lower rate of survival when challenged by dsRNA targeting these three genes via a nanomaterial-promoted RNAi method. In addition, silencing of BtCht10 significantly resulted in a longer duration of development compared to control nymphs. These results indicate a key role of BtCht10, BtCht5, and BtCht7 in B. tabaci nymph molting. Our research depicts the differences of chitinase-like family genes in structure and function and identified potential targets for RNAi-based whitefly management.

The herbaceous peony (Paeonia lactiflora Pall.) has high ornamental and nutritional value, and the seeds of P. lactiflora can be used to produce high-quality edible oil. However, low seed yield limits the application of P. lactiflora. This can be mitigated by insect pollinators. Here, we evaluated the pollination services of honeybees (Apis mellifera L.) in a P. lactiflora field. We found that A. mellifera provided pollination for P. lactiflora throughout the day especially in the period from 10:00–15:00. Seed number and weight were significantly increased when P. lactiflora was pollinated by A. mellifera. Furthermore, a DNA barcode, the rbcL gene, was used to analyze pollen samples from the corbiculae (pollen baskets) of A. mellifera (bee pollen, BP) and P. lactiflora flowers (flower pollen, FP). High homology of rbcL genes in the BP and FP suggested that BP was collected from P. lactiflora. Based on our results, A. mellifera provided efficient pollination for P. lactiflora. Therefore, A. mellifera could be a good candidate pollinator for P. lactiflora and could be applied in the field.

Ascorbic acid (AsA) is one of the most abundant natural antioxidants, and it is an important indicator of the nutritional value of cucumber fruit. The aim of this study was to elucidate the regulatory mechanism affecting AsA metabolism in cucumber fruit. In this study, the AsA content in the fruit of two cucumber cultivars (H28 and H105) was significantly higher in the exocarp and endocarp than in the mesocarp. To clarify the regulation of AsA in cucumber fruit, the transcriptomes of three fruit tissues (i.e., the exocarp, mesocarp, and endocarp) of two cucumber cultivars (H28 and H105) were sequenced. Transcriptomic profiling combined with transcription factors (TFs) and correlation analysis were performed to reveal that three genes, including CsaV3_5G014110 (phosphomannomutase, PMM), CsaV3_2G004170 (GDP-mannose-3′, 5′-epimerase, GME) and CsaV3_5G006680 (dehydroascorbate reductase, DHAR), were expressed at higher level in the exocarp and endocarp than in the mesocarp. In both two cultivars, CsaV3_4G028360 (ethylene-responsive transcription factor, ERF) was negatively correlated with PMM and GME, and positively correlated with DHAR. CsaV3_6G042110 (ethylene-responsive transcription factor, ERF) was positively correlated with PMM and GME, and negatively correlated with DHAR. CsaV3_6G032360 (mitogen-activated protein kinase, MAPK) as positively correlated with PMM, GME and DHAR. These six genes are considered the key candidate genes for further research. This study provides insight for further study on the regulation of AsA biosynthesis in cucumber fruit and provide potential candidate genes for future genetic improvement of cucumber germplasm with enhanced AsA accumulation.

Tomato brown rugose fruit virus (ToBRFV) represents a significant threat to global tomato production, resulting in decreased yields and compromised fruit quality due to the formation of brown, hardened spots on infected fruit. This study aimed to elucidate the molecular mechanisms for ToBRFV-induced lesions in tomato fruit using transcriptome sequencing and virus-induced gene silencing (VIGS) techniques. Transcriptome analysis was conducted on tomato fruit at green-ripe (L), and red-ripe (H) stages, examining three tissue types: brown lesions (B), non-brown areas of infected fruit (BC), and healthy controls (CK). A total of 34 differentially expressed genes (DEGs) related to phenylpropanoid biosynthesis were identified, with PAL (Solyc05g056170.3), C4H (Solyc05g047530.3), CAD (Solyc02g069250.3), and POD (Solyc02g094180.3) showing the highest transcript abundances in brown lesion tissues. Crucially, silencing POD (Solyc02g094180.3) increased tomato susceptibility to ToBRFV, accompanied by increased accumulation of hydrogen peroxide (H₂O₂), and superoxide anions (O₂•⁻). In contrast, silencing PAL (Solyc05g056170.3), C4H (Solyc05g047530.3), or CAD (Solyc02g069250.3) improved resistance and suppressed viral accumulation. Collectively, these findings indicate that these four genes are crucial regulators of lignin biosynthesis in tomato, and that the brown hardened lesions induced by ToBRFV are associated with lignin accumulation. Furthermore, POD plays a vital role in mediating resistance to ToBRFV by regulating reactive oxygen species. This study provides important insights into the molecular responses of tomato fruit, laying a foundation for breeding ToBRFV-resistant tomato varieties with improved fruit quality.