Video: How roots grow

A group of researchers literally watched meristem genes turn on and off in a cyclical fashion in the developing roots of higher plants, such as conifers and ferns, according to a study published in Science today (10th September). This oscillating expression, they say, is how these plants form their complex root systems. As the root meristem grows downward into the soil, it produces undifferentiated cells that, once assigned their function, will form the intricate root system of the plant. What type of root the cells become is determined in an area a fixed distance behind the growing root tip called the "oscillation zone", where specific genes in the cells turn on and off like clockwork. Depending on which genes are on and which are off when the "oscillation zone" passes through determines the cells' capacity for producing lateral roots, which anchor the plant firmly into the soil and facilitate water...