A new study by scientists at the University of Birmingham has revealed a group of cells that function as a 'brain' for plant embryos, capable of assessing environmental conditions and dictating when seeds will germinate.
A plant's decision about when to germinate is one of the most important it will make during its life. Too soon, and the plant may be damaged by harsh winter conditions; too late, and it may be out-competed by other, more precocious plants.
The scientists showed that the 'decision-making centre' in a plant called Arabidopsis, or thale cress, contains two types of cell - one that promotes seed dormancy, and one that promotes germination. These two groups of cells communicate with each other by moving hormones, an analogous mechanism to that employed by our own brains when we decide whether or not to move.
The scientists used mathematical modelling to show that communication between the separated elements controls the plant's sensitivity to its environment. Following this theory, they used a mutant plant where cells were more chemically linked - essentially enhancing communication between circuit elements - to show that germination timing depends on these intra-region signals.
The mathematical theory describing the brain's function predicted that more seeds would germinate when exposed to varying environments, such as fluctuating temperatures, than to constant environments. The scientists tested this theory in the lab and found exactly this behaviour.
'Our work has important implications for understanding how crops and weeds grow,' adds Prof Bassel.