The link between hydrotropism and phototropism in Arabidopsis roots

When exposed to one-sided blue light, the roots of plants such as Arabidopsis thaliana exhibit negative phototropism and curve away from the light. The genes MIZU-KUSSEI1 (MIZ1) and GNOM/MIZ2 play important roles in positive hydrotropism, the process by which roots grow in a direction towards water. Intriguingly, mutations in these genes cause a dramatic loss of phototropism. Pang et al. (2023) found out that the same tissues in Arabidopsis roots involved in MIZ1- and GNOM/MIZ2-regulated hydrotropism are also required for phototropism.

Automated summary

Research found that negative phototropism and positive hydrotropism in Arabidopsis roots are closely associated with the genes MIZ1 and GNOM/MIZ2. Mutations in these genes result in loss of phototropism.