The study screened Spirodela polyrhiza genotypes and identified strain SP162 as amenable to Agrobacterium-mediated transformation via tissue culture, providing a robust protocol for stable reporter gene expression and CRISPR/Cas9 genome editing. Additionally, the weak small RNA silencing in S. polyrhiza allows prolonged transgene activity in transient assays, and the authors released the genome, strain, and a web portal for gene exploration and gRNA design.

The authors optimized a complete in vitro transformation pipeline for the duckweed Spirodela polyrhiza, achieving 90‑100% efficiency at callus induction, transient and stable transformation, marker‑free selection, and regeneration of plants that retain transgene expression for over 100 generations within weeks. This streamlined workflow removes major bottlenecks and enables high‑throughput functional genomics and synthetic biology in this fast‑growing aquatic monocot.

The study examined transposable element (TE) silencing in the duckweed Spirodela polyrhiza, which exhibits unusually low DNA methylation, scarce 24‑nt siRNAs, and missing RdDM components. While degenerated TEs lack DNA methylation and H3K9me2, they retain heterochromatin marks H3K9me1 and H3K27me1, whereas the few intact TEs show high DNA methylation and H3K9me2, indicating a shift in RdDM focus toward potentially active TEs and suggesting heterochromatin can be maintained independently of DNA methylation in flowering plants.

The study investigated sugar loading mechanisms in the giant duckweed Spirodela polyrhiza and found that it lacks typical sucrose transporter genes and does not use active apoplastic or symplastic loading, instead employing passive symplastic phloem loading characterized by uniform plasmodesmata density. Hormone‑induced reduction of plasmodesmata permeability lowered sucrose levels in phloem exudate, pinpointing plasmodesmata regulation as a key factor in carbon export for this monocot species.