Plants adapt exquisitely to their environment: physiology and metabolism
change diurnally and in response to many environmental conditions, and reproductive
development is generally sensitive to day length, temperature, or
other proxies of seasonal change. The most fundamental adaptation to environmental
change in plants is altered growth behavior, involving changes to
root or shoot growth patterns, rates, or both.
Despite their fundamental importance for our understanding of plant
growth, for rational approaches to sustainably enhance yields in agriculture
and forestry and, ultimately, for human welfare, we still understand surprisingly
little about the mechanisms that govern growth in plants. In this
chapter, I will consider the signals and genetic mechanisms involved in controlling
growth in aerial and underground organs.