Early Flowering (ELF) Gene Integrates Vegetative Growth, Flowering Regulation, and Reproductive Development in Arabidopsis thaliana

Early flowering-related factors play pivotal roles in coordinating plant growth and reproductive development. In this study, we investigated the biological function of early flowering gene (ELF) in Arabidopsis thaliana using CRISPR/Cas9-mediated genome editing and construction of overexpression approaches. Two independent ELF overexpression (OE-ELF) and genome-edited (ge-elf) lines were generated and systemically analyzed. ELF overexpression significantly enhanced early seedling performance, increasing germination rate and seedling fresh weight by up to 8.7%, while genome-edited lines exhibited a marked reduction. Root growth was strongly promoted in OE-ELF plants, with root length increase of 85% and 75%, whereas ge-elf lines showed a reduction of up to 48%. At later developmental stages, OE-ELF plants displayed enhanced vegetative growth, including increased leaf length (32%), leaf area (91%), and accelerated flowering (21% earlier than wild type). In contrast, ge-elf delayed flowering by up to 25% and resulted in compact plant architecture. Reproductive development was severely compromised in ge-elf plants, which exhibited malformed inflorescences, reduced pollen germination, shortened silique (45%), and a drastic decrease in seed number per silique (70%). Conversely, OE-ELF plants showed increased silique number and seed per silique. Molecular analysis revealed that ELF positively regulates key flowering-related genes, including FLC, SOC1, AP1, and LFY, which correlated strongly with growth and reproductive traits. Our results demonstrate that ELF functions as a central regulator integrating vegetative growth, floral development, male fertility, and seed production in Arabidopsis thaliana.