Unveiling the wheat-rust battleground: A transcriptomic journey

The global wheat production faces significant challenges due to major rust-causing fungi, namely Puccinia striiformis f. sp. tritici, P. triticina, and P. graminis f. sp. tritici, responsible for stripe, leaf, and stem rust diseases, respectively. The evolutionary relationship between wheat (host) and Puccinia (pathogen) renders existing wheat resistance ineffective over time. The most viable solution to this issue lies in the development of new resistant wheat varieties. However, achieving this requires a comprehensive understanding of wheat's defense mechanisms against ever-evolving pathogens. Transcriptomics emerges as a powerful tool for analyzing gene activity at the molecular level. Over the last decade, this technique has transformed our comprehension of the wheat-rust interaction. Transcriptomics has unveiled a compelling "biphasic model" of gene expression in wheat infected with rust fungi, delineating two distinct phases of defense activation. Moreover, it has illuminated the intricate signaling pathways, hormonal interactions, and diverse defense mechanisms employed by wheat. These mechanisms encompass the oxidative burst, reinforcement of cell walls, and controlled cessation of photosynthesis, all aimed at combatting the invading pathogen. However, the utility of transcriptomics extends beyond elucidating defense strategies; it enables the identification of novel genes linked to resistance or susceptibility. By unraveling the functions of these genes, researchers can uncover new avenues for breeding resistant wheat varieties, arming wheat with the molecular arsenal necessary to prevail in the ongoing battle against rust fungi. This review represents a pioneering effort in exploring transcriptomic techniques and accumulated data to present a comprehensive overview of the wheat-Puccinia interaction at the system-wide level.