A study conducted by scientists at the University of Birmingham reveals that
a group of cells function as a 'brain' for plant embryos capable of
assessing environmental conditions and dictates when seeds will germinate. A
plant's decision to germinate is a key process that it makes during its
life. Too soon, and the plant may be damaged by harsh winter conditions; too
late, and it may be outcompeted by other, more precocious plants.
The scientists show that the 'decision-making center' in the plant
Arabidopsis contains two types of cell: one promotes seed dormancy, the
other promotes germination. These two groups of cells communicate with each
other by moving hormones, an analogous mechanism that the human brain
employs to decide whether or not to move.
The study, published in the Proceedings of the National Academy of Sciences
(PNAS), used mathematical modelling to show that communication between the
separated elements controls the plant's sensitivity to its environment. They
used a mutant plant where cells were more chemically linked, to show that
germination time depends on these intra-region signals. The model also
predicted that more seeds would germinate when exposed to varying
environments, such as fluctuating temperatures, than constant environments,
such as constant temperatures.