How do trees decide when and where their branches grow?
In: Biology
By default, trees want to make branches everywhere, but the top of the tree sends a signal down saying, “no!” As the trunk grows higher, the lower parts of the tree start to have trouble hearing the top and start to grow a branch. That branch turns into a mini-trunk, also saying, “no!” to all the other parts of the tree thinking of making a branch. This keeps happening over and over again. Different trees have louder tips, parts that have better or worse hearing, and parts that eventually decide to stop growing, which is how we get so many different shapes of trees.
Tree top shouting = auxin and other hormones released from meristems.
Rest of the tree = active layers of cells just under the bark / dermis.
Listening = genetic regulatory responses to the auxin / hormones.
Latest Answers