For humans hair is like an accessory, we spend money cutting it, styling it, and coloring it; almost everything we do with our hair is for superficial reasons (except for cilia in our intestines, nasal cavity etc). Animals have fur for protective purposes, to keep warm in the summer or perhaps camouflage. I have never really thought about the hair plants have on their roots. After all my high school and college biology classes I still didn’t know what purpose root hairs served for plants!

Root hairs serve a very important function for plants; they secrete acids and chemicals that break down soil, sediments, and rocks which release potassium and other minerals for the plants to absorb. Crops that are able to grow longer hairs usually have higher yield, especially in arid conditions. Researchers from University of Oxford and John Innes Centre have discovered a transcription factor called RSL4 that controls root hair growth. According to the research, when the gene was continuously activated the growth continued linearly as well. Also, environmental factors such as low potassium levels in the soil work in conjunction with internal factors such as auxin signals to control RSL4 activity.

This research can provide means for crops to be grown efficiently in harsh environmental conditions as well as shed light on the pathways that plants use to grow root hairs.

Discussion Question: From our knowledge about auxin mechanisms, how do you think it controls RSL4?

News Article: http://www.sciencedaily.com/releases/2010/02/100217093938.htm
Paper Abstract: http://www.nature.com/ng/journal/vaop/ncurrent/full/ng.529.html