Overexpression of FLZ12 Suppresses Root Hair Development and Enhances Iron-Deficiency Tolerance in Arabidopsis.

Background: The Arabidopsis FCS-LIKE ZINC FINGER (FLZ) family proteins play crucial roles in responses to various biotic and abiotic stresses, but the functions of many family members remain uncharacterized. Methods: In this study, we investigated the function of FLZ12, a member of the FLZ family, using a reverse genetic approach. Results: We found that overexpression of FLZ12 impaired root hair development, as evidenced by marked reductions in both root hair length and number under normal growth conditions. However, deprivation of phosphate could partially restore root hair formation, although it still impeded root hair elongation. Notably, FLZ12-overexpressing lines exhibited greatly enhanced tolerance to iron deficiency, with seedlings exhibiting more vigorous and robust growth compared to wild-type plants. In contrast, knockout of FLZ12 resulted in slight impact on seedling development. Further analysis revealed that FLZ12 accumulation was increased in vascular tissues of plants subjected to iron starvation, and the protein was predominantly localized within the nucleus. Conclusions: Integrating these findings with existing evidence, we propose that FLZ12 functions as a translational regulator through interacting with other proteins, playing dual roles in root hair development and iron-deficiency responses in Arabidopsis. These findings provide new insights into the FLZ-domain-containing proteins and offer molecular strategies to enhance iron uptake efficiency in crops, highlighting FLZ12 as a promising candidate for future breeding efforts.