Drought stress disrupts plant growth, metabolism, and reproduction, with devastating effects on crop productivity worldwide. Blackcurrant, although rich in health-promoting compounds, is highly vulnerable to water deficits, often producing fewer flowers and aborting developing fruit. Previous transcriptome studies provided only fragmented insights, and no reference genome existed for the Grossulariaceae family until now. Without such genomic tools, identifying precise stress-responsive genes and linking them to metabolite dynamics remained challenging. Based on these challenges, there is a pressing need to conduct integrated genome-scale, transcriptomic, and metabolomic studies to uncover blackcurrant’s drought response mechanisms.
A research team from Forschungszentrum Jülich, Heinrich Heine University Düsseldorf, the University of Málaga, the National Institute of Horticulture Research in Poland, and the Norwegian Institute of Bioeconomy Research has published (DOI: 10.1093/hr/uhae313) a new study on November 11 2024, in Horticulture Research. The study reports the first chromosome-scale, haplotype-resolved genome assembly of blackcurrant and its application to analyze drought stress responses. By combining advanced sequencing technologies with transcriptomic and metabolomic profiling, the team identified key genes and metabolites that underlie the plant’s adaptation to water scarcity.
The researchers sequenced the German blackcurrant cultivar Rosenthals Langtraubige using a hybrid strategy of PacBio HiFi, Oxford Nanopore long reads, and Pore-C data, achieving an assembly of eight pseudo-chromosomes with over 98% completeness. This is the first reference genome for Ribes or the Grossulariaceae family, marking a major genomic milestone. With this resource, they exposed plants to drought for several days and conducted transcriptomic and metabolomic analyses. The results showed widespread transcriptional reprogramming: more than 8,000 differentially expressed genes in roots and nearly 800 in leaves, including families such as bZIP, WRKY, MYB, and NAC. Receptor-like kinases and MAPK cascade components were especially affected, revealing complex signaling adjustments. Metabolite profiling identified significant accumulation of osmoprotective compounds, including proline, GABA, and branched-chain amino acids (valine, isoleucine). Citric acid, a central tricarboxylic acid cycle intermediate, was notably depleted, reflecting altered respiration under drought. Integration of gene and metabolite data highlighted links between amino acid metabolism, GABA biosynthesis, and stress signaling pathways.
These results show that blackcurrant mobilizes a coordinated gene–metabolite network under drought, providing essential targets for developing more robust cultivars.
“Our study provides the first comprehensive genomic blueprint of blackcurrant and demonstrates how it responds at both the gene and metabolite levels under drought stress,” said lead author Freya Ziegler. “By integrating genomics with transcriptomics and metabolomics, we uncovered not just which genes are switched on or off, but how this translates into biochemical adjustments in the plant. These insights offer valuable tools for breeding programs and open opportunities to engineer cultivars that can thrive despite increasing climate-related drought events”.
The new genome assembly and drought-response map represent a foundational resource for blackcurrant research and breeding. With precise markers for stress-responsive genes and metabolites, breeders can accelerate the selection of drought-tolerant cultivars, reducing yield losses in increasingly dry climates. Beyond blackcurrant, this genomic framework can guide studies in related Ribes species, including redcurrant and gooseberry. The integration of genome and metabolite data also provides a model for how minor fruit crops can benefit from cutting-edge omics research. Ultimately, these findings support the development of climate-smart horticulture, ensuring that berry crops maintain productivity and nutritional value in future food systems.
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References
DOI
10.1093/hr/uhae313
Original Source URL
https://doi.org/10.1093/hr/uhae313
Funding information
This study was funded by the European Union’s Horizon 2020 program under grant agreement number 679303.
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.