Scientists from the United States and Saudi Arabia have identified
beta-cyclocitral, a plant hormone that makes tomato and rice plants roots
grow faster and branch more. Beta-cyclocitral speeds root growth when added
to soil. A commonly found hormone in plants, it also makes rice plants
resistant to salty soil.
The researchers wanted to find plant hormones that affected root
development. Their previous research hinted that some molecules related to
carotenoids might be important. Using Arabidopsis, the team tested about 20
carotenoids that have been repurposed and are available as food additives
and found that beta-cyclocitral stood out. According to coauthor Jazz
Dickinson, it is possible that the compound helped the roots push down
through the salty topsoil to reach the deeper, less-salty soil more quickly.