Volatile organic compounds released from entomopathogenic nematode-infected insect cadavers for the biocontrol of Meloidogyne incognita.

BACKGROUND: Root-knot nematodes (RKNs), Meloidogyne spp., are one of the most destructive polyphagous plant-parasitic nematodes. They pose a serious threat to global food security and are difficult to control. Entomopathogenic nematodes (EPNs) show promise in controlling RKNs. However, it remains unclear whether the volatile organic compounds (VOCs) emitted from EPN-infected cadavers can control RKNs. RESULTS: We investigated the fumigation activity of VOCs released from cadavers infected by five different species of EPNs on RKNs in Petri dishes, and found that VOCs released from Steinernema feltiae (SN strain) and S. carpocapsae (All strain) infected cadavers had a significant lethal effect on second-stage juveniles (J2s) of Meloidogyne incognita. The VOCs released from the cadavers infected with S. feltiae were analyzed using SPME-GC/MS. Dimethyl disulfide (DMDS), tetradecane, pentadecane, and butylated hydroxytoluene (BHT), were selected for a validation experiment with pure compounds. The DMDS compound had significant nematicidal activity and repelled J2s. DMDS also inhibited egg hatching and the invasion of tomato roots by J2s. In a pot experiment, the addition of S. feltiae-infected cadavers and cadavers wrapped with a 400-mesh nylon net also significantly reduced the population of RKNs in tomato roots after 7 days. The number of root knots and eggs was reduced by 58% and 74.34%, respectively, compared to the control. CONCLUSION: These results suggested that the VOCs emitted by the EPN-infected cadavers affected various developmental stages of M. incognita and thus have the potential to be used in controlling RKNs through multiple methods. © 2024 Society of Chemical Industry.

CTHRC1 targeted by miR-30a-5p regulates cell adhesion, invasion and migration in lung adenocarcinoma.

The morbidity of lung cancer ranks first among all cancers. Lung adenocarcinoma (LUAD) is a classification of lung cancer, and cell invasion and migration of LUAD are the main causes for its high mortality. Therefore, further exploring the potential mechanism of LUAD metastasis may provide bases for following targeted drug development and treatment of LUAD. In this study, clinical data as well as gene expression profiles were obtained from TCGA-LUAD and GEO to analyze CTHRC1 expression. The result found that CTHRC1 was significantly high in LUAD. Similar results were also discovered in 4 cancer cell lines. Moreover, overexpressed/knock-down CTHRC1 cell lines were constructed. It was uncovered that overexpressing CTHRC1 promoted LUAD cell migration and invasion, and inhibited cell adhesion, while knocked down CTHRC1 had the opposite effect. Afterward, the upstream miRNAs that regulated CTHRC1 were predicted by several bioinformatics websites. It was testified by dual-luciferase method that CTHRC1 was negatively mediated by miR-30a-5p. Overexpressed miR-30a-5p suppressed cell invasion/migration, and increased cell adhesion, while overexpressing CTHRC1 as well reversed such impacts. In conclusion, it was disclosed in this study that CTHRC1 worked as a cancer promoter in LUAD, and miR-30a-5p could target and downregulate CTHRC1 to regulate cell adhesion, and inhibited LUAD cell invasion and migration. These results elucidated at cellular level that upregulated CTHRC1 may be a marker protein for LUAD metastasis.

Current Knowledge and Perspectives of Pyrrolizidine Alkaloids in Pharmacological Applications: A Mini-Review.

Pyrrolizidine alkaloids (PAs) are a widespread group of secondary metabolites in plants. PAs are notorious for their acute hepatotoxicity, genotoxicity and neurological damage to humans and animals. In recent decades, the application of PAs for beneficial biological activities to cure disease has drawn greater attention. Here, we review the current knowledge regarding the pharmacological properties of PAs and discuss PAs as promising prototypes for the development of new drugs.

Genome-Wide Analysis of Chemosensory Protein Genes (CSPs) Family in Fig Wasps (Hymenoptera, Chalcidoidea).

Chemosensory proteins (CSP) are a class of acidic soluble proteins which have various functions in chemoreception, resistance and immunity, but we still have very little knowledge on this gene family in fig wasps, a peculiar insects group (Hymenoptera, Chalcidoidea) that shelter in the fig syconia of Ficus trees. Here, we made the first comprehensive analysis of CSP gene family in the 11 fig wasps at whole-genome level. We manually annotated 104 CSP genes in the genomes of the 11 fig wasps, comprehensively analyzed them in gene characteristics, conserved cysteine patterns, motif orders, phylogeny, genome distribution, gene tandem duplication, and expansion and contraction patterns of the gene family. We also approximately predicted the gene expression by codon adaptation index analysis. Our study shows that the CSP gene family is conserved in the 11 fig wasps; the CSP gene numbers in pollinating fig wasps are less than in non-pollinating fig wasps, which may be due to their longer history of adaptation to fig syconia; the expansion of CSP gene in two non-pollinating fig wasps, Philotrypesis tridentata and Sycophaga agraensis, may be a species-specific phenomenon. These results provide us with useful information for understanding the evolution of the CSP gene family of insects in diverse living environments.

Methyl Jasmonate Changes the Composition and Distribution Rather than the Concentration of Defence Compounds: a Study on Pyrrolizidine Alkaloids.

In this study we investigated the effect of methyl jasmonate (MeJA) application on pyrrolizidine alkaloid (PA) concentration and composition of two closely related Jacobaea species. In addition, we examined whether MeJA application affected herbivory of the polyphagous leaf feeding herbivore Spodoptera exigua. A range of concentrations of MeJA was added to the medium of Jacobaea vulgaris and J. aquatica tissue culture plants grown under axenic conditions. PA concentrations were measured in roots and shoots using LC-MS/MS. In neither species MeJA application did affect the total PA concentration at the whole plant level. In J. vulgaris the total PA concentration decreased in roots but increased in shoots. In J. aquatica a similar non-significant trend was observed. In both Jacobaea species MeJA application induced a strong shift from senecionine- to erucifoline-like PAs, while the jacobine- and otosenine-like PAs remained largely unaffected. The results show that MeJA application does not necessarily elicits de novo synthesis, but rather leads to PA conversion combined with reallocation of certain PAs from roots to shoots. S. exigua preferred feeding on control leaves of J. aquatica over MeJA treated leaves, while for J. vulgaris both the control and MeJA treated leaves were hardly eaten. This suggests that the MeJA-induced increase of erucifoline-like PAs can play a role in resistance of J. aquatica to S. exigua. In J. vulgaris resistance to S. exigua may already be high due to the presence of jacobine-like PAs or other resistance factors.