Fruit shape diversity in the Brassicaceae is generated by varying patterns of anisotropy.
Fruits exhibit a vast array of different 3D shapes, from simple spheres and cylinders to more complex curved forms; however, the mechanism by which growth is oriented and coordinated to generate this diversity of forms is unclear. Here, we compare the growth patterns and orientations for two very different fruit shapes in the Brassicaceae: the heart-shaped Capsella rubella silicle and the near-cylindrical Arabidopsis thaliana silique. We show, through a combination of clonal and morphological analyses, that the different shapes involve different patterns of anisotropic growth during three phases. These experimental data can be accounted for by a tissue-level model in which specified growth rates vary in space and time and are oriented by a proximodistal polarity field. The resulting tissue conflicts lead to deformation of the tissue as it grows. The model allows us to identify tissue-specific and temporally specific activities required to obtain the individual shapes. One such activity may be provided by the valve-identity gene FRUITFULL, which we show through comparative mutant analysis to modulate fruit shape during post-fertilisation growth of both species. Simple modulations of the model presented here can also broadly account for the variety of shapes in other Brassicaceae species, thus providing a simplified framework for fruit development and shape diversity.
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi 00100, Kenya.
Tilly
T
Eldridge
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Łukasz
Ł
Łangowski
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Nicola
N
Stacey
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Friederike
F
Jantzen
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Laila
L
Moubayidin
Institute for Biochemistry and Biology, University of Potsdam, Potsdam 14476, Germany.
Adrien
A
Sicard
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Paul
P
Southam
University of East Anglia, Norwich NR4 7TJ, UK.
Richard
R
Kennaway
Institute for Biochemistry and Biology, University of Potsdam, Potsdam 14476, Germany.
Michael
M
Lenhard
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK lars.ostergaard@jic.ac.uk enrico.coen@jic.ac.uk.
Enrico S
ES
Coen
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK lars.ostergaard@jic.ac.uk enrico.coen@jic.ac.uk.
Lars
0000-0002-8497-7657
L
Østergaard
D016880:Anisotropy; D017360:Arabidopsis / Q000033:anatomy & histology / Q000378:metabolism; D019607:Brassicaceae / Q000033:anatomy & histology* / Q000378:metabolism*; D029687:Capsella / Q000033:anatomy & histology / Q000378:metabolism; D005638:Fruit / Q000033:anatomy & histology* / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant
Anisotropic growth; Arabidopsis; Brassicaceae; Capsella; Fruit shape; Modelling