By Eric Hamilton
As plants stretch toward the summer sun, they are marching toward one of the most important decisions of their lives — when to flower. Too early, and they might miss out on key pollinators. Too late, and an early frost could damage their developing seeds.
Farmers who rely on their crops to flower at just the right time can only sit and worry. It’s up to the plants.
That decision of when to flower is ultimately made by cells that must stop sending out leaves in order to start producing flowers. Scientists typically think of these critical decisions about cell fate as being controlled by the balance between one group of regulating proteins that accelerate cells toward one fate and other proteins that keep the brakes on. When the brake is released at the right cue, the cell marches toward its destiny as leaf, or flower.
But new research published Aug. 6 in the journal Nature Genetics by University of Wisconsin–Madison biologists has discovered a previously unknown mechanism for controlling cellular decisions, one which combines an on-and-off switch in a single protein. Professor of Genetics and Wisconsin Institute for Discovery researcher Xuehua Zhong and her lab found that the protein EBS can bind to two different chemical modifications on histones, proteins that DNA wraps around, either promoting or preventing the transition to flowering in plants.
Because the basic building blocks of EBS are found across plants and animals, this style of regulating crucial decisions about development and tissue generation is likely to be widespread. The researchers say that this linking of a developmental on-and-off switch in one protein provides opportunities for improving crops and could also help scientists study diseases like cancer.
Every organism starts out as a single cell, which means that a cell must be able to express both flower and leaf genes, although not at the same time. These young cells are undecided about their fate.
Click here to see more...