Duckweeds shrank by compressing, not discarding, the plant blueprint

Duckweeds, the smallest flowering plants on Earth, have long puzzled biologists because they seem to have shed the elaborate architecture that defines most land plants. A new study from the University of Nottingham, published in Current Biology, now shows that these millimetre-scale plants did not lose their body plan at all. Instead, they compressed it. Using gene expression analysis and advanced microscopy, researchers found that duckweeds retain the same fundamental building blocks found in the shoots of larger plants, but those structures have been dramatically squeezed together and fused into a body that can measure just a few millimetres across.

The finding challenges a common assumption about miniaturisation. In animals, becoming tiny is often associated with the loss of organs or body structures, as seen in miniature frogs, fish, and insects that simplify their anatomy to fit a reduced frame. Duckweeds took a different evolutionary route. Rather than throwing away parts of the blueprint, they appear to have packed every component into an incredibly compact form, fusing neighbouring elements that remain separate in larger relatives. The result is a complete flowering plant, complete with roots, flowers, and a functioning shoot, occupying a space smaller than a pencil eraser.

Dr Anthony Bishopp, who led the study, explained the surprise at the heart of the work. When the team looked closely at duckweed shoots, the basic organisation was still there. The compressed and fused components preserved the essential relationships of a conventional plant shoot, meaning that duckweed is not a simplified or primitive organism but a fully elaborated plant rendered in miniature. This reframing matters because it gives researchers a new way of thinking about how plants can evolve to become so small without sacrificing the features that make them viable, reproductive organisms.

Duckweeds belong to a family that includes some of the largest herbaceous plants, making the size range within this lineage extraordinary. The contrast between a few-millimetre duckweed and its giant relatives highlights how flexible the angiosperm body plan can be. Understanding the mechanisms behind this flexibility is not just an academic curiosity. It touches on one of the central questions of developmental biology: how does a genome and a developmental program produce a complete organism across such wildly different scales?

The research team combined gene expression profiling with cutting-edge microscopy to map the internal anatomy of duckweed shoots at unprecedented detail. By identifying which genes are active in which tissues, they could confirm that the compressed structures correspond to the same cell types and tissue layers found in larger plants. The microscopy revealed the physical arrangement of these tissues, showing how leaves, stems, and other shoot components are packed into a volume orders of magnitude smaller than in typical flowering plants. Together, these approaches provided both molecular and structural evidence that miniaturisation occurred through compression rather than deletion.

Dr Alex Ware, co-author of the study, noted that duckweeds are astonishingly small, so it is tempting to think of them as either primitive plants or simply as having lost parts, but this is not the case. The research adds to growing evidence from across the research community about this plant and will help efforts to turn them into a future crop. That practical goal is driving rapid growth in duckweed research worldwide, as scientists and agriculturalists recognise the potential of these tiny plants as a source of food and novel protein on Earth.

Unlike most crops grown today, which have been shaped by thousands of years of domestication and selective breeding, the potential of duckweed remains largely unexplored. Even the basic architecture of the duckweed plant has remained something of a mystery until now. Understanding how its body is organised provides an essential framework for understanding how duckweed grows, develops, and functions, and ultimately how its potential might be improved. Without this foundational knowledge, efforts to breed or engineer duckweed for higher yields or better nutrition would proceed blindly, without knowing which traits matter or how they are controlled.

The implications extend beyond terrestrial agriculture. Duckweeds are being considered as a possible crop for future space missions, where their small size, rapid growth, and high protein content could make them ideal candidates for closed-loop life support systems. A plant that packs a complete body plan into a few millimetres, grows quickly, and produces edible biomass could be invaluable on long-duration missions where every cubic centimetre and every watt of energy counts. The new understanding of duckweed architecture gives space agriculture researchers a clearer picture of what these plants can do and how they might be optimised for off-world cultivation.

The study, titled Miniaturization of duckweeds occurred through compression of the angiosperm body plan, represents an experimental study published in Current Biology with the DOI 10.1016/j.cub.2026.09.035. It opens the door to further research into the genetic and developmental mechanisms that allow such extreme size reduction. If scientists can identify the specific genetic switches that control compression and fusion in duckweeds, those insights could potentially be applied to other crops, creating more compact plants that produce more food per unit of space. In a world where arable land is increasingly scarce and space exploration is accelerating, the humble duckweed, long overlooked as a pond nuisance, may prove to be one of the most important model organisms of the coming decades.

Subject of Research: Miniaturisation of duckweeds through compression of the angiosperm body plan

Article Title: Scientists uncover how the world’s smallest flowering plant became so tiny

Article References: Scientists uncover how the world’s smallest flowering plant became so tiny. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: duckweed, miniaturisation, plant development, gene expression, microscopy, Current Biology, University of Nottingham, angiosperm body plan, future crops, space agriculture, novel protein, plant architecture