How a Delicate Root Can Penetrate Hard Rock

We have all seen plants growing through cracks in concrete or bedrock and wondered how a delicate root can penetrate hard rock. Recent research has shown that the root jackhammer process is highly complex.

In a paper published in the journal Current Biology, a group of researchers discovered some of the secrets of how a delicate root can penetrate hard rock. For one thing, the optimum angle for the root tip to attack is 90 degrees. Striking the hard object at a different angle could cause the root to deflect. A protein called OsAUX1 keeps the root tip pointed down.

Another way that roots are similar to a jackhammer is that the root hairs provide an anchor for the root, and OsAUX1 causes more root hairs to grow. If you have ever seen a worker using a jackhammer, you know that someone has to hold it tight, or it will bounce on the material’s surface instead of penetrating.

Another protein that helps explain how a delicate root can penetrate hard rock is PIEZO1. If the root continued to grow quickly when it contacts a rigid material, it would likely bend or break. PIEZO1 signals the root to slow down when it encounters a hard barrier. This “touch-sensitive” protein shows more engineering involved in root growth. In all, 14 proteins, plus genes, promoters, hormones, and tissues enable roots to perform their amazing stunts.

The importance of this design is Earth-shattering, or should we say rock-shattering. It explains how soil is produced in an area where rock dominates Earth’s surface, as in a lava flow or an intrusive rock like granite. The process is like a jackhammer in which root caps use weaknesses in the host rock to penetrate and break the rock into smaller pieces so plants can secure the nutrients they need.

Some plants in unusual environments don’t use roots in the same way. Plants living in ocean environments or along sand bars, such as mangroves, have a different process to sustain themselves. Air ferns and epiphytes don’t have the same kind of root system as a maple tree. The diversity of plant life and how each type of plant handles its environment is a great testimony to design and the wisdom of the Creator.

— John N. Clayton © 2024
Reference: Evolution News & Science Today