PIPages
Labs

Jacob Suissa

University of Tennessee-Knoxville, TN·Ecology & Evolution

Do new body forms evolve mainly because natural selection directly favors them, or do they appear as side effects of how organisms grow? This project addresses that long-standing question in biology using ferns.

Fields

Ecology & Evolution

Plant Science & Agriculture

Biology

Topics

ferns

vascular architecture

stele

Grants
1 known grant, through Jul 2029

What they work on

  1. Test the Drought-Driven Hypothesis by measuring how vulnerable fern leaves, rhizomes and roots are to drought-induced embolism, the air blockages in water-conducting tubes, and linking this to vascular anatomy at architectural, tissue and cellular scales.
  2. Test the Ontogenetic Hypothesis by asking whether the shape of the stele, the central vascular core, varies with growth traits such as rhizome diameter and leaf arrangement across more than 300 fern species.
  3. Capture 3D vascular networks with micro-computed tomography (microCT) and traditional tissue sectioning, using AI-based image segmentation to measure vascular features across large image datasets.
  4. Use phylogenetic comparative methods and climate data from species occurrences to test how water transport and development together explain large-scale evolutionary patterns in fern vascular architecture.

More about the research

Ferns have evolved some of the most varied vascular systems on Earth, the networks of tubes that carry water and nutrients through a plant.

Why it matters

Knowing how plant water-transport systems relate to drought tolerance could improve predictions of how plants respond to drought, which matters for agricultural productivity. The work could also inform crop breeding by clarifying how growth patterns generate new plant forms that selection then acts on. More broadly, it adds basic understanding of how new anatomical structures arise and evolve.

Known grants

From NIH and NSF research grants. Labs often have other funding we can't see.

The evolution of fern vascular architecture

NSF · Aug 2026 – Jul 2029

Closest labs

Helen Holmlund

Pepperdine University, CA·Plant Science & Agriculture

Compare water-use anatomy and physiology in hydrated, closely related desiccation-tolerant and non-tolerant ferns and lycophytes across six lineages, to find which traits go with surviving near-complete drying.

Troy Ocheltree

Colorado State University-Fort Collins, CO·Plant Science & Agriculture

Identify the networks of linked physiological traits that produce different drought-coping strategies in grasses, using a set of species that spans the entire grass family (Poaceae).

Craig Brodersen

Yale University, CT·Plant Science & Agriculture

Measure guard cell and epidermal cell turgor pressure directly in living leaves, using a laser-induced gas bubble whose collapse rate reveals the pressure inside the cell.

The school

University of Tennessee-Knoxville: 16 labs on PI Pages, $387M a year on research, 426 research doctorates a year.

More about University of Tennessee-Knoxville

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