Mediator subunit 16 functions in the regulation of iron uptake gene expression in Arabidopsis

• DOI: 10.1111/nph.12860
• Publication Date: 2014-05-29T09:22:55Z
• Authors: Yue Zhang; Huilan Wu; Ning Wang; Huajie Fan; Chunlin Chen; Yan Cui; Hongfei Liu; Hong‐Qing Ling
• Keywords: Mediator

Summary Iron is an essential nutrient for plant growth and development, its absorption tightly controlled. Under iron limitation, FIT dimerizes with the four Ib bHLH proteins activates expression of uptake genes. However, how dimerized complex downstream genes remains unclear. Using forward genetics, a low‐iron‐sensitive mutant was screened. The corresponding gene ( MED 16 ) isolated, biological functions in homeostasis were characterized using approaches such as expression, protein subcellular localization, protein–protein interaction chromatin immunoprecipitation assay. Lesion MED16 significantly reduced FRO2 IRT1 Arabidopsis roots. mutants showed low shoot concentration severe leaf chlorosis under whereas it grew normally wild‐type sufficiency. Furthermore, we that interacted improved binding FIT/Ib to promoters iron‐deficient conditions. Additionally, found many response genes, which are regulated by FIT, also controlled MED16. In conclusion, involved deficiency response, modulates limitation. Our results increase understanding molecular regulation mechanisms underlying plants.