Abstract
The metabolite profile changes induced by Fe deficiency in leaves and xylem sap of several Strategy I plant species have been characterized. We have confirmed that Fe deficiency causes consistent changes both in the xylem sap and leaf metabolite profiles. The main changes in the xylem sap metabolite profile in response to Fe deficiency include consistent decreases in amino acids, N-related metabolites and carbohydrates, and increases in TCA cycle metabolites. In tomato, Fe resupply causes a transitory flush of xylem sap carboxylates, but within 1 day the metabolite profile of the xylem sap from Fe-deficient plants becomes similar to that of Fe-sufficient controls. The main changes in the metabolite profile of leaf extracts in response to Fe deficiency include consistent increases in amino acids and N-related metabolites, carbohydrates and TCA cycle metabolites. In leaves, selected pairs of amino acids and TCA cycle metabolites show high correlations, with the sign depending of the Fe status. These data suggest that in low photosynthesis, C-starved Fe-deficient plants anaplerotic reactions involving amino acids can be crucial for short-term survival.
Highlights
Iron is an essential micronutrient in plants, involved in processes such as photosynthesis, respiration, and others (Marschner, 1995)
The aim of this study was to test the hypothesis that Fe deficiency may cause consistent changes in the xylem sap and leaf metabolite profiles in Strategy I plant species
Xylem sap and whole leaf extract metabolite profiles were obtained by GC–MS, following the normalized procedures developed by Fiehn et al (2008)
Summary
Iron is an essential micronutrient in plants, involved in processes such as photosynthesis, respiration, and others (Marschner, 1995). In calcareous and alkaline soils, Fe is mainly found as poorly soluble oxides and/or hydroxides, and the amount of Fe available to plants is very low. Since 30% of cultivated plants are grown in calcareous soils, Fe deficiency is often a major constraint for crop productivity (Hansen et al, 2006; Rombolà and Tagliavini, 2006). Upon sensing Fe shortage, plants develop different mechanisms that promote Fe mobilization and uptake from the rhizosphere. Strategy I is based on the reduction of rhizospheric Fe by an Fe reductase enzyme (FRO; Robinson et al, 1999), and the subsequent uptake by root cells through an Fe(II) transporter (IRT; Eide et al, 1996). Strategy II relies on the synthesis and excretion of phytosiderophores (PS) to the rhizosphere, and the resulting Fe(III)–PS complexes are taken up by plasma membrane YSL-type transporters (Curie et al, 2009)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call