Paulownia tree and sustainable bioeconomy: applications, current research, and biotechnological advances

The genus Paulownia (Paulowniaceae) is a short-rotation, coppicing hardwood native to East Asia that has been adopted as a multipurpose bioeconomy crop in more than fifty countries. Four decades of research have generated a large but fragmented literature: individual applications are well documented, yet they have rarely been evaluated together. The central question this review addresses is therefore not whether Paulownia is useful, but whether its many uses can be sequenced into a single, economically coherent production cycle. This review synthesizes quantitative evidence across the value chain, spanning wood composites, particleboard, and nanocellulose; bioenergy, including bioethanol via simultaneous saccharification and fermentation, biohydrogen via dark–photo co-fermentation; biochar for soil amendment and as a carbon-black substitute in rubber; animal nutrition, in which Paulownia leaf meal matches alfalfa in crude protein (14 to 23%) and lowers enteric methane in dairy cattle by roughly 14%; premium honey; and pharmacologically active flavonoids and verbascoside. Eighteen published in vitro micropropagation protocols are consolidated, and Agrobacterium -mediated and biolistic transformation are identified as the rate-limiting step. for commercial clonal deployment. A Scopus and Web of Science bibliometric analysis (1,390 documents; 1990 to 2025) documents exponential publication growth and a thematic shift from taxonomy toward application-driven research. Together, this evidence supports a staggered revenue model in which companion cropping, honey, and leaf feed generate early income (years 1 to 3), biochar and biomass contribute at mid-rotation (years 3 to 6), and premium timber closes the 10 to 12-yr cycle. Critical gaps persist in water-use physiology, life-cycle carbon accounting, and integrated pest management.