Induction of root Fe(lll) reductase activity and proton extrusion by iron deficiency is mediated by auxin-based systemic signalling in Malus xiaojinensis

• DOI: 10.1093/jxb/err314
• Publication Date: 2011-11-05T20:54:16Z
• Authors: T. Wu; H.-T. Zhang; Y. Wang; W.-S. Jia; X.-F. Xu; X.-Z. Zhang; Z. H. Han
• Keywords: Malus

Iron is a critical cofactor for number of metalloenzymes involved in respiration and photosynthesis, but plants often suffer from iron deficiency due to limited supplies soluble the soil. induces series adaptive responses various plant species, mechanisms by which they are triggered remain largely unknown. Using pH imaging hormone localization techniques, it has been demonstrated here that root Fe(III) reductase activity proton extrusion upon up-regulated systemic auxin signalling Fe-efficient woody plant, Malus xiaojinensis. Split-root experiments Fe-deprivation portion system induced dramatic increase Fe-supplied portion, suggesting were mediated signalling. Reciprocal grafting M. xiaojinensis with baccata, no capability produce corresponding responses, indicate initiation likely be determined roots rather than shoots. substantial IAA content shoot apex supplying exogenous analogues (NAA) could mimic trigger responses. Conversely, preventing transport blocked These results strongly deficiency-induced physiological