Chaphamaparvovirus (ChPV) is an ancient virus that has been detected in a variety of hosts. In this study, based on the phylogenetic analysis and the adaptability of ChPV to multiple hosts, we evaluated the potential of feline (FeChPV) and canine ChPV (CaChPV) for cross-species transmis-sion. Phylogenetic analysis showed that FeChPV and CaChPV were closely related. Notably, two strains of ChPVs isolated from domestic cats and 2 from dogs clustered together with CaChPVs and FeChPVs, respectively, suggesting the stringent boundaries between canine and feline ChPV may be broken. Further analysis revealed that CaChPV and FeChPV were more adapted to dogs than to cats, strongly suggesting the possibility of unidirectional or bidirectional transmission be-tween dogs and cats. Mutation analysis identified several shared mutations in cross-species-transmissible strains that were not located within immune epitopes. Furthermore, the VP struc-tures of FeChPV and CaChPV exhibited a high degree of similarity across both cross-species-transmissible and non-cross-species-transmissible strains. However, definitive experimental evi-dence is lacking, and its capacity for cross-species transmission should be approached with cau-tion and elucidated in further studies.

Fusarium wilt (FW) caused by Fusarium oxysporum f. sp. Cucumerinum (Foc) of cucumber is a destructive soil-borne disease in cucumber (Cucumis sativus.L). There is limited knowledge on molecular mechanisms to FW resistance-mediated defense responses in cucumber. In this study, metabolome and transcriptome profiling were carried out in two FW, resistant (NR) and susceptible (NS), near isogenic lines (NILs) before and after Foc inoculation. The NILs showed consistent and stable FW resistances in multiple greenhouse and laboratory screening tests. Widely targeted metabolomic analysis identified differentially accumulated metabolites (DMAs) with significantly more accumulation in NR in response to Foc infection including many phenolic acid and flavonoid compounds from the flavonoid biosynthesis pathway. Transcriptome analysis identified differentially expressed genes (DEGs) between the NILs upon Foc inoculation including genes for secondary metabolite biosynthesis in or transcription factor genes regulating the flavonoid biosynthesis pathway. Joint analysis of the metabolomic and transcriptomic data identified DAMs and DEGs closely associated with biosynthesis of phenolic acid and flavonoid DAMs. The association of these compounds with NR-conferred FW resistance was exemplified by in vivo assays in which two phenolic acid compounds, bis (2-ethylhexyl) phthalate and diisooctyl phthalate, and the flavonoid compound gallocatechin 3-O-gallate were shown to have significant inhibitory effect on Foc growth. The antifungal effect of three compounds seems to be a novel finding. We conclude that phenolic acids and flavonoids play an important role in NR mediated FW resistance in cucumber.