Korla Fragrant Pear Genes and Metabolites Shift During Black Spot Infection

Researchers have mapped how Korla fragrant pear, a fruit tree native to Xinjiang, China, responds at the molecular level to black spot disease, a fungal infection caused by Alternaria alternata that triggers early defoliation and fruit rot and imposes significant economic losses in pear production. In a study published in BMC Plant Biology, the team combined transcriptome and metabolome profiling of pear leaves sampled at multiple time points after inoculation, aiming to fill a gap in understanding how pear species react to this pathogen — knowledge that has so far limited progress in breeding disease-resistant trees.

The dual approach revealed an extensive molecular response. Compared with the pre-inoculation baseline at 0 hours, the analysis identified 17,362 differentially expressed genes, while comparison against time-matched mock-inoculated controls yielded 9,840 such genes. A core set of 9,008 genes common to both comparisons was then clustered into six distinct expression profiles, with pathway enrichment analysis carried out for each cluster separately.

On the metabolic side, the profiling detected 2,596 differentially regulated metabolites relative to the 0-hour baseline and 2,616 relative to the mock controls, with 2,017 metabolites shared between the two comparisons. When the transcriptomic and metabolomic datasets were integrated, three major response-associated pathways stood out: flavonoid biosynthesis, photosynthesis-related processes, and plant hormone signal transduction, suggesting that the pear’s defense involves coordinated changes in gene expression, secondary metabolism, energy production, and hormonal signaling.

To narrow the field of candidates for further study, the researchers applied weighted gene co-expression network analysis, which identified 12 candidate hub genes. These include six transcription factors and three genes belonging to the flavonoid pathway, all flagged for subsequent functional validation. The authors emphasize that the work provides an integrated overview of the transcriptomic and metabolic changes associated with the Korla fragrant pear response to A. alternata infection and prioritizes candidate genes for future validation, rather than demonstrating function of the genes themselves. As an open-access, peer-reviewed study published on 27 October 2026, it offers a resource for breeders seeking resistance traits, though the identified hub genes remain candidates until experimental validation confirms their roles in defense against the pathogen.

Subject of Research: Transcriptomic and metabolomic responses of Korla fragrant pear to black spot disease caused by Alternaria alternata

Article Title: Integrated transcriptomic and metabolomic analysis of Korla fragrant pear responses to black spot disease caused by Alternaria alternata

Article References: Song, B., Xu, B., Zhang, L., He, T., & Zhu, X. (2026). Integrated transcriptomic and metabolomic analysis of Korla fragrant pear responses to black spot disease caused by Alternaria alternata. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10072-0

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10072-0

Keywords: Korla fragrant pear, black spot disease, Alternaria alternata, transcriptomics, metabolomics, differentially expressed genes, flavonoid biosynthesis, plant hormone signaling, WGCNA, hub genes, disease resistance, Xinjiang