책임운영기관 농촌진흥청 국립축산과학원 (로고)

Italian ryegrass (Lolium multiflorum L.) is an annual forage crop widely cultivated across the globe for its excellent nutritional value and high productivity. Despite its importance, studies on differentially expressed genes (DEGs) involved in its morphogenesis remain limited. In this study, we employed a high-yielding mutant line developed through radiation mutagenesis to identify candidate genes associated with morphogenesis, focusing on Expansins (EXPs), GRFs (Growth regulating factors), GIFs (GRF-interacting factors), and growth hormone-related genes. RT-qPCR primers were designed, and differential gene expression analysis was performed. Gene expression was assessed in the leaves of seedlings at one to three weeks of age, comparing the control cultivar 'Kowinearly' with the mutant line. Expression patterns fell into four distinct categories: (1) genes consistently exhibiting lower expression in the mutant line across all developmental stages; (2) genes showing persistently low expression in the mutant, while the control displayed a sharp increase at early stages followed by a decline; (3) genes with low expression in the control but a marked early-stage increase in the mutant; and (4) genes with decreasing expression over time in the mutant, contrasting with gradually increasing expression in the control. These expression profiles highlight Actin and GRF6 as Group 1 genes, AXR1 (Auxin-resistant protein 1) and EXPB6 (c) as Group 2 genes, PEVMPP1 (Pyrophosphate-energized vacuolar membrane proton pump 1) as a Group 3 gene, and EF1A (Elongation factor 1-alpha) as a Group 4 gene, all of which are key candidate genes for the development of high-yielding Italian ryegrass cultivars.