Integrated analysis of the metabolome and transcriptome provides insights into anthocyanin biosynthesis of cashew apple.

The cashew apple remains an underutilized agricultural product despite its abundance as a by-product of cashew nut production. Anthocyanins are water-soluble pigments responsible for red, purple, and blue hues in plant tissues and have various health-promoting properties. To investigate the anthocyanin biosynthesis in cashew apples, fruits with varying peel colors from three cultivars were subjected to integrative analyses with metabolomics and transcriptomics. Through a UPLC-ESI-MS/MS-based targeted metabolomics analysis, a total of 26 distinct anthocyanin compounds were identified in the fruits of the three cashew cultivars. Subsequent quantification revealed that Pelargonidin-3-O-galactoside, Petunidin-3-O-arabinoside, and Cyanidin-3-O-galactoside were the primary contributors responsible for the red pigmentation in cashew apple peels. Following transcriptomic analysis showed that the expression levels of anthocyanin biosynthetic genes were predominantly higher in the red cashew apples as compared to the other two cultivars. Moreover, correlation analysis revealed that eight potential transcription factors implicated in the regulation of anthocyanin biosynthesis. Among these, four transcription factors exhibited positive correlations with both anthocyanin contents and anthocyanin biosynthetic gene expression, while the remaining four transcription factors displayed negative correlations. These findings provide a comprehensive understanding of the molecular basis of anthocyanin biosynthesis in cashew apple peels.

Metabolomic and transcriptomic analyses provide insights into metabolic networks during cashew fruit development and ripening.

Cashew nut is a popular food around the world. The high-resolution profiles and dynamics of metabolomes in cashew fruits are poorly understood till now. In this study, we analyzed the temporal metabolome of cashew nut via a non-targeted method based on UHPLC-Q-Exactive-MS, and analyzed that of cashew apple via a widely targeted method based on UHPLC-QTRAP-MS/MS (MRM). Furthermore, we performed integrative analyses of temporal metabolome and transcriptome data, characterized the accumulation of specific metabolites, and identified the transcriptional changes during cashew fruit development. Specifically, we found that phosphatidylinositol species were the predominant fractions in the unsaturated glycerophospholipids, and we identified a transcription factor that was the potential regulator of phosphatidylinositol biosynthesis. Analysis of cashew apple revealed metabolic genes and transcription factors involved in sugar biosynthesis. Taken together, our results provide insights into metabolic networks during cashew fruit development and generate a valuable resource for further cashew breeding studies.

Sub-subgenotype 2.1c isolates of classical swine fever virus are dominant in Guangdong province of China, 2018.

Classical swine fever (CSF) continues to be a devastating infectious disease for the swine industry in China and commonly exists as wild or atypical types. From June 3rd to October 3rd, 2018, outbreaks of typical CSF cases with mortality rates of 42-86% occurred in 11 swine herds in five cities of Guangdong province, and were confirmed by RT-PCR. Phylogenetic analyses based on the nucleotide sequences of full-length E2 genes showed that the CSFV isolates collected in Guangdong, 2018 grouped into sub-subgenotype 2.1c and formed a separate clade from previously identified 2.1c isolates. Sequence comparison further confirmed the distance between the novel emergent and previously identified 2.1c isolates, with shared 94.5-98.2% and 97.8-99.7% identities at the nucleotide and amino acid levels respectively. Furthermore, 2.1c isolates collected in 2018 from Guangdong province contained a unique amino acid substitution (K174R) in the E2 protein in comparison with other 2.1c representative strains and CSFV 2.1, 2.2, 2.3 strains. Of note, the novel emergent 2.1c isolates are neutralized by sera from C-strain vaccinated sows, indicating that C-strain is still efficacious for protection against field isolates of CSFV.