Analysis of ROS Performance and FIT Gene Expression of rhd2 Mutant in Response to Fe Deficiency

Abstract

Iron (Fe) is one of the main micronutrients required for plant growth and development. Fe uptake signaling under Fe deficiency was determined to be involved in ROS. This study aimed to evaluate the changes in H₂O₂ content and ROS localization of the rhd2 mutant roots, the expression of the stress marker ZAT12 gene, and the central transcriptional factor regulating Fe uptake (FIT) in response to Fe deficiency. The results showed an increase of H₂O₂ content under Fe deficiency, but this increase did not involve the activity of NADPH oxidase encoding the RBOH C gene or by other RBOH genes. ROS was also localized in Fe-deficient roots compared to plants grown under Fe-sufficient conditions, except for the root tips. The root length grown under Fe-deficient conditions was shorter than under Fe-sufficient conditions. When treated with exogenous H₂O₂, the H₂O₂ content was increased, but ROS was reversely localized from root tips under Fe-deficient conditions. The level of FIT gene expression induced under Fe deficient condition increased in the rhd2 mutant compared to the Col-0 genotype. Reversely, the decreased level of ZAT12 gene expression was detected in the rhd2 mutant.  So the expression of ZAT12 is mediated by ROS-generated NADPH oxidase encoded by RBOH C.