Underground networks of roots forage for nutrients and water for plants
sustenance. Yet, the genetic and molecular mechanisms that govern which
parts of the soil roots explore remain largely unknown. In a breakthrough
that will help reduce atmospheric carbon from plants, researchers from Salk
Institute have discovered a gene that determines the depth of root growth in
the soil. The findings of this study will allow researchers to develop
plants that can help combat climate change as part of Salk's Harnessing
Plants Initiative.



The researchers used thale cress (Arabidopsis thaliana) to identify genes
that regulate the way auxin works. Auxin is a hormone which plays a key role
in controlling the root system architecture of plants. The team found that
the gene called EXOCYST70A3 directly regulates root system architecture by
controlling the auxin pathway without disrupting other pathways. The gene
does this by affecting the distribution of PIN4, a protein that influences
auxin transport. When the researchers altered the EXOCYST70A3 gene, they
found that the orientation of the root system shifted and more roots grew
deeper into the soil.

In addition to developing plants that can grow deeper root systems that will
store more carbon, this discovery could help scientists understand how
plants address the seasonal variance in rainfall and how to help plants
adapt to changing climates.

[www.salk.edu]
nts-to-fight-climate-change/