Exploring the wild relatives of major cereals for abiotic stress tolerance through pan-transcriptomics

Modern crop cultivars possess much narrower genetic diversity due to continuous selective breeding over the centuries. This has led to their reduced ability to adapt to various stresses. Crop wild relatives (CWRs) are a huge reservoir of untapped genetic diversity. CWRs contain a wide range of alleles that confer tolerance to drought, heat, salinity, cold, heavy metal toxicity, and resistance to pests and diseases. However, the genomic complexity and diversity of CWRs make the identification and characterization of stress-responsive alleles challenging. Pan-transcriptomics offers a powerful framework to overcome these limitations by integrating the transcriptomic profiles of diverse CWRs, enabling the discovery of core and dispensable stress-responsive gene sets, novel transcript variants, and accession-specific expression modules that underlie adaptive phenotypes. This review highlights pan-transcriptomics as a discovery platform for harnessing the genetic potential that will contribute to the development of climate-resilient, high-yielding crop varieties.