Duckweeds: from fundamental biology to a sustainable plant chassis for biotechnology

Duckweeds (Lemnaceae), the smallest and fastest-growing flowering plants, have emerged as a transformative platform for sustainable biotechnology. This review synthesizes recent advances that underpin their potential as a next-generation plant chassis. We discuss duckweed's unique biology, characterized by reductive evolution, extreme phenotypic plasticity, and a simplified epigenome that favors transgene expression. The decoding of its minimalist genome, along with the establishment of efficient genetic tools including optimized transformation and CRISPR-Cas9 editing, enables precise genetic and metabolic engineering. While traditional uses in phytoremediation and animal feed validate its utility, duckweed's rapid growth in contained, soil-free culture and its edibility offer distinct advantages for molecular farming over established systems like tobacco. We highlight progress in engineering duckweeds to produce vaccines, therapeutic proteins, and high-value metabolites. To transition from proof-of-concept to an industrial workhorse, future efforts must focus on integrated omics databases, universal genetic toolkits, and scalable cultivation. Converging fundamental insights with synthetic biology principles positions duckweed as a versatile and powerful chassis for the bioeconomy.