Abstract:Iron is an essential nutrient for plant growth, but also a limiting factor for crop production due to its low solubility and availability in soil. The expression of a variety of genes would be induced under iron deficiency, while to many of these genes, the mechanisms remains unclear. CYP82C4(At4g31940) is one of the iron starvation induced gene and regulated by FIT in Arabidopsis. In this study, the promotor of CYP82C4 was linked to Luciferase to screen the T-DNA insertion mutant library for genes in response to iron deficiency in Arabidopsis. After screening, a line L22-8 was identified to remarkably intensify the fluorescence of CYP82C4 in both iron sufficient and deficient conditions. Real time qPCR analysis showed that the expression levels of endogenous CYP82C4 was increased in root and shoot under normal growth condition, and in shoot under iron deficiency condition, but not the shoot in shortage of iron. The expression of several Fe-marker genes, such as FIT, bHLH38 and bHLH39, et al., were also significantly changed. These results indicated that the T-DNA insertion of L22-8 affected the molecular response of Arabidopsis to iron deficiency stress and CYP82C4 may play an important role in the formation of heterodimer of FIT withbHLH38 and bHLH39. The T-DNA insertion site of the L22-8 strain was detected to be located between At3g51950 and At3g51960 by reverse PCR, and the transcriptional expression of these two genes was slightly lower in mutant than Col-0 under normal conditions. Complementary analysis confirmed that At3g51960 could partially recover the L22-8 fluorescence signal, suggesting its role in regulating the response of CYP82C4 to iron deficiency stress. In addition, the contents of total Fe, P and Zn in shoot of L22-8 had no differences compared with Col-0, indicating that there maybe exsit some other interactive genes of CYP82C4 in Arabidopsis. Our results further extend the molecular regulation network of iron uptake and utilization in plant, and provide guidance for molecular breeding.