A review of ARGOS-mediated regulation of plant organ size: molecular mechanisms, environmental interactions, and agricultural implications.

Improving crop productivity relies on a thorough comprehension of genetic modules that coordinate plant organ growth with environmental adaptation. ARGOS (Auxin-Regulated Gene involved in Organ Size), ARGOS-LIKE (ARL), and Organ Size Related (OSR) proteins constitute a family of small membrane associated proteins widely found in plants, which participate in auxin and ethylene responses, as well as the regulation of cell proliferation and expansion. Functional studies in Arabidopsis and various crops reveal that ARGOS homologs regulate the development of leaves, roots, stems and reproductive organs, with experimental support differing considerably among species and research systems. In Arabidopsis, AtARGOS promotes organ growth mainly by prolonging the cell proliferation period and functions upstream of ANT and CYCD3;1 in the genetic pathway. In maize, modifications to ZmARGOS family genes have been proven to improve field performance under drought conditions. Conversely, the connections between ARGOS and light, temperature, ABA, GA and BR signaling are mostly inferred from large scale hormone and growth regulatory networks, rather than confirmed direct mechanisms. Here, we review the current advances in ARGOS/ARL/OSR research, distinguish direct experimental evidence from speculative regulatory models, and explore the prospects of applying promoter engineering, cis-regulatory editing and allele mining to characterize and deploy these genes for crop genetic improvement.