The genetic basis for leaf shape diversity: exploiting the Arabidopsis thaliana relative Cardamine hirsuta
Project code: HA 6316/1-3
Leaves present an iconic and prevalent example of biodiversity as they are abundant in the biosphere and show striking variation in shape. However, it is not clear how such diversity is generated or what its adaptive significance is. Leaf form can be classified as simple, where the leaf blade is entire like in the model plant Arabidopsis thaliana, or dissected where the blade is divided into leaflets like in Cardamine hirsuta. In the past few years we have made key contributions to understanding the genetic pathways underlying formation of compound leaves by developing the A. thaliana relative C. hirsuta into a powerful experimental system to study diversification of leaf form in an unbiased fashion. We leverage the simple genetics and transformation in both species to understand the mechanistic basis for leaf shape evolution.
Natural variation in Cardamine hirsuta.
The aim of this project is to understand the genetic basis for the difference in leaf shape between A. thaliana and its relative C. hirsuta, and to determine whether similar or divergent developmental processes underlie leaf shape variation within C. hirsuta. To this end we will pursue the following objectives:
- Genetic basis of interspecific variation: To understand how the leaf complexity gene REDUCED COMPLEXITY (RCO) acts, we will identify RCO target genes and determine whether those dominate the C. hirsuta-specific leaf transcriptome.
- Genetic basis of intraspecific variation: We will test whether heterochronic variation is a major contributor to natural variation in C. hirsuta leaf shape by mapping quantitative trait loci (QTL) for leaf complexity and cloning a major effect QTL.
- Selective forces influencing leaf shape variation: We will test whether genes controlling inter- or intraspecific leaf shape variation evolved under positive selection, and test the fitness of leaf shape variants acting at each scale.
Publications related to the project
- Cartolano, M., Pieper, B., Lempe, J., Tattersall, A., Huijser, P., Tresch, A., Darrah, P. R., Hay, A., and Tsiantis, M. (2015) Heterochrony underpins natural variation in Cardamine hirsuta leaf form PNAS 112 10539-10544.
- Vlad D, Kierzkowski D, Rast M I, Vuolo F, Dello Ioio R, Galinha C, Gan X, Hajheidari M, Hay A, Smith R S, Huijser P, Bailey C D, Tsiantis M (2014). Leaf shape evolution through duplication, regulatory diversification and loss of a homeobox gene. Science 343: 780-3.
- Hay A, Pieper B, Cooke E, Mandáková T, Cartolano M, Tattersall A, Dello Ioio R, McGowan S, Barkoulas M, Galinha C, Rast M, Hofhuis H, Then C, Plieske J, Ganal M, Mott R, Martinez-Garcia J, Carine M, Scotland R, Gan X, Filatov D, Lysak M and Tsiantis M (2014). Cardamine hirsuta: a versatile genetic system for comparative studies. The Plant Journal 78(1): 1-15.
- Kougioumoutzi E, Cartolano M, Canales C, Dupre M, Bramsiepe J, Vlad D, Rast M, Dello Ioio R, Tattersall A, Schnittger A, Hay A and Tsiantis M (2013). SIMPLE LEAF3 encodes a ribosome-associated protein required for leaflet development in Cardamine hirsuta. The Plant Journal 73: 533-45.
- Piazza P, Bailey C D, Cartolano M, Krieger J, Cao J, Ossowski S, Schneeberger K, He F, de Meaux J, Hall N, MacLeod N, Filatov D, Hay A and Tsiantis M (2010). Arabidopsis thaliana Leaf Form Evolved via Loss of KNOX Expression in Leaves in Association with a Selective Sweep. Current Biology 20: 2223-8.
