The Role of TuACO Gene Family in Response to Biotic and Abiotic Stresses in Triticum urartu.

BACKGROUND: Ethylene is one of the most important plant hormones. ACC oxidase (ACO) plays a vital role in ethylene synthesis and responses to biotic and abiotic stresses in plants. However, its function in Triticum urartu remains unclear. This study aims to systematically identify the members of the TuACO gene family to elucidate its response characteristics and functions under biotic and abiotic stresses. METHODS: Through homologous alignment, phylogenetic evolution analysis, and investigations of gene structure and promoter cis-elements, a total of eight TuACO genes were identified in the T. urartu genome based on their homology to OsACO and AtACO protein sequences. RESULTS: These genes were classified into five ACO subfamilies and distributed across chromosomes 1A, 4A, 5A, 6A, and 7A. TuACO gene families contained 0-3 introns and 1-4 exons. The protein sequence contains 10 different conservative motifs. QRT-PCR expression analysis revealed that the transcript levels of TuACO5a, TuACO5b, and TuACO3a were significantly upregulated at 6 and 24 h after infection with powdery mildew, a biotic stress. Under boron deficiency, an abiotic stress, the expression of TuACO6 and TuACO1b increased, whereas the expression of TuACO5b and TuACO3b was markedly induced under high-boron conditions. CONCLUSIONS: These results demonstrate that TuACO genes exhibit functional diversification in response to biotic and abiotic stresses, which lays the foundation for elucidating their gene functions.