skip to content

Sainsbury Laboratory

Microscopy images of the traps and meristem area of Utricularia gibba, which is more commonly known as floating bladderwort.

3D Morphogenesis

The Whitewoods Group aims to understand how plants pattern themselves in three dimensions (3D).

We investigate how plants coordinate their overall leaf shape with intricate internal patterning to produce leaves that are exquisitely adapted to their function, be that light capture for photosynthesis in flat leaves or prey capture for nutrient uptake in carnivorous plants.

To do this we combine computational modelling with genetic and developmental analysis in the flat-leaved model plant Arabidopsis thaliana and the floating aquatic carnivorous plant Utricularia gibba. We have several projects that feed into each other to give an integrated understanding of 3D morphogenesis:

 

In this video Chris Whitewoods talks about how he uses Utricularia gibba, a carnivorous bladderwort, to investigate leaf shape using developmental analysis, genetic manipulation and computational modelling.

 

Genetic basis of air space development and evolution

Intercellular air spaces make up to 70% of leaf volume and are vital for leaf function. In flat leaves air spaces are associated with stomata and maximise gas exchange for photosynthesis, while in aquatic plants these air spaces have become enlarged and aid floatation. However, despite being a major part of leaf structure we do not understand how air spaces form, or how new air space patterns evolve.

To identify novel regulators of air space formation we perform forward and reverse genetic screens in A. thaliana and U. gibba. We identify plants with altered air spaces and map the genes that underlie these phenotypes. One such screen identifies sinking U. gibba plants, which have reduced air space development. We combine these genetic approaches with computational modelling and inducible genetic changes to understand exactly how these genes influence development and control air space formation. We also perform comparative experiments to investigate how these genes have been modified through evolution to control differences in air space patterning between plant species.

 

Intercellular air spaces within the leaf of aquatic carnivorous plant Utricularia gibba. Large leaf air spaces like these allow aquatic plants to float.

 

Cell division, growth and intercellular adhesion in air space development

Leaf air spaces form by cells being pulled apart, but how plants regulate this process is unknown. We generate computational models to predict the effect of cell division, expansion and adhesion on air space formation, and test these hypotheses using inducible genetic changes to alter growth, cell wall properties and intercellular adhesion. These approaches allow us to investigate how differential growth and cell adhesion contribute to air space formation in A. thaliana and U. gibba.

 

Wild-type U. gibba (left) floats in water whereas mutant U. gibba (right) with smaller air spaces sinks to the bottom of the water column.

 

Genetic control of growth in 3D

Several groups of carnivorous plants evolved cup-shaped leaves to trap prey and access a new source of food. Despite our ongoing fascination with carnivorous plants, we don’t really understand how they evolved such complex cup-shaped traps from simple flat leaves. To develop complex shapes such as flat leaves and carnivorous plant traps, plants must control their growth in three dimensions. Our previous work proposed that growth is patterned in three dimensions based on a framework of two interacting orthogonal polarity fields. We are currently testing this hypothesis by identifying the molecular determinants of these polarity fields and investigating how changes in these factors underlie development in the flat leaves of A. thaliana and the cup-shaped carnivorous traps of U. gibba.

 

A Utricularia gibba trap expressing GFP localised to cell membranes. Transgenic lines like this allow us to analyse development and gene function in U. gibba.

 

Key publications

Whitewoods CD*, Gonçalves B*, Cheng J*, Cui M, Kennaway R, Lee K, Bushell C, Yu M, Piao C. and Coen E. 2020. Evolution of carnivorous traps from planar leaves through simple shifts in gene expression. Science. https://doi.org/10.1126/science.aay5433

Lee K*, Bushell C*, Kiode Y*, Fozard J, Piao C, Yu M, Newman J, Whitewoods CD, Avondo J, Kennaway R, Maree A, Cui M. and Coen E. 2019. Shaping of a three-dimensional carnivorous trap through modulation of a planar growth mechanism. PLOS Biology. https://doi.org/10.1371/journal.pbio.3000427

Dennis R, Whitewoods CD and Harrison CJ. 2019. Quantitative methods for like-for-like comparison in analyses of Physcomitrella patens phyllid development. Journal of Bryology.  https://doi.org/10.1080/03736687.2019.1668109

Whitewoods CD*, Cammarata J*, Nemec Venza Z, Sang S, Crook AD, Aoyama T, Wang X, Waller M, Kamisugi Y, Cuming A, Svövényi P, Nimchuk ZL, Roeder AHK, Scanlon MJ and Harrison CJ. 2018. CLAVATA was a genetic novelty for the morphological innovation of 3D growth in land plants. Current Biology. https://doi.org/10.1016/j.cub.2018.05.068

 

Reviews

Whitewoods CD. Riddled with holes: Understanding air space formation in plant leaves. PLoS Biology. 2021;19(12):e3001475. http://dx.doi.org/10.1371/journal.pbio.3001475

Whitewoods CD. 2020. Utricularia: Quick Guide. Current Biology

Whitewoods CD and Coen E. 2017. Growth and development of three-dimensional plant form. Current Biology 27: R910-R918. https://doi.org/10.1016/j.cub.2017.05.079

Contact

 

Dr Chris Whitewoods
Career Development Fellow
Sainsbury Laboratory
University of Cambridge
47 Bateman Street
Cambridge CB2 1LR
Email: chris.whitewoods@slcu.cam.ac.uk

 

Whitewoods Group Members