MIZ1 acts downstream of PGM1 in regulating root hydrotropism

The MIZ1 play an important role in root hydrotropism. However, the relationship between MIZ1-regulated hydrotropism and amyloplast-mediated gravitropism remain largely unclear. Here, we generated the miz1/ pgm1 double mutants by crossing the non-hydrotropic miz1 mutant with the amyloplast-defective pgm1 mutant, which lacks gravitropic response. Our results showed that the miz1/pgm1 mutants exhibited a significant reduction in amyloplast and gravitropic bending, while maintaining a similar ahydrotropic phenotype as the miz1 single mutant. These findings suggest that MIZ1 plays a role in hydrotropism downstream of PGM1. Understanding the mechanisms of interaction between hydrotropism and gravitropism is crucial for comprehending the rooting patterns of plants in natural conditions. The counteracting relationship between root hydrotropism and gravitropism in the miz1 mutant should receive attention in this field, particularly considering the interference from gravitropism on Earth.

Automated summary

The MIZ1 protein is important for root hydrotropism, but its relationship with amyloplast-mediated gravitropism is not well understood. In this study, miz1/pgm1 double mutants were generated to investigate this relationship. The results showed that MIZ1 plays a role in both amyloplast development and gravitropic bending, while maintaining the non-hydrotropic phenotype of the miz1 mutant.