The mechanics of Arabidopsis seed germination

Abstract

Germination is defined as the protrusion of the embryonic radicle through the
seed coat layers (endosperm and testa). As the radicle elongates, the testa
ruptures, followed by rupture of the endosperm. Arabidopsis seeds exhibit a
two-step germination process with sequential rupture of the testa and
endosperm.

We are interested in exploring the physical process of germination. Whilst
much effort has previously been placed on genetic networks, a mathematical
approach for furthering the understanding of the physical/mechanical
properties of germination has not yet been described.

The Mathematics in Plant Sciences Study Group helped us to develop a
better understanding of the problem. Several different mathematical models
were generated for radicle growth and endosperm stretching. These models
were developed on multiscale dimensions – looking at the organ, tissue and
cellular levels.

The outcomes of the study group have heightened our interest in the
mechanical aspects of germination, and we are currently progressing with a
grant proposal – a collaboration between the Schools of Biosciences and
Engineering at the University of Nottingham, and a group from the
Department of Biology at the University of Freiburg, Germany.