Characterization of the chemical state of iron in the leaves of wild-type tomato and of a nicotianamine-free mutantChloronerva by X-ray absorption near-edge structure (XANES)

Abstract

Forms of iron in leaves of wild‐type tomato (Lycopersicon esculentum Mill. cv. Bonner Beste) and of the nicotianamine‐free mutant, chloronerva, were analysed by X‐ray absorption near‐edge structure (XANES). The XANES spectra of the wild‐type leaf veins and of the interveinal areas of leaves of both wild‐type and chloronerva had a lower edge energy than the spectrum of the chloronerva leaf veins. This decrease may be caused by the presence of ferrous iron. Thus nicotianamine may play an important role in maintaining iron in the ferrous form in the veins of tomato leaves. Copyright © 2000 John Wiley & Sons, Ltd.

Application of NanoSIMS and isotopic labeling to analyze the spatial distribution of the plant iron chelator nicotianamine

“…When applying NA, these differences between chln and WT disappeared, suggesting that NA is necessary to solubilize and utilize the apoplastic Fe. X-ray Absorption Near-edge Structure (XANES) also showed that the presence of ferrous Fe was lower in the chln leaf veins than in WT or interveinal areas, suggesting that NA may be involved in maintaining Fe in the ferrous form in the veins of tomato leaves ( 40 ). In agreement, Fe localization was mainly observed in the vasculature of the roots, stem, and leaves ( Figure 3 , Figure 4 , Figure 5 ).…”

Application of NanoSIMS and isotopic labeling to analyze the spatial distribution of the plant iron chelator nicotianamine

“…When applying NA, these differences between chln and WT disappeared, suggesting that NA is necessary to solubilize and utilize the apoplastic Fe. X-ray Absorption Near-edge Structure (XANES) also showed that the presence of ferrous Fe was lower in the chln leaf veins than in WT or interveinal areas, suggesting that NA may be involved in maintaining Fe in the ferrous form in the veins of tomato leaves ( 40 ). In agreement, Fe localization was mainly observed in the vasculature of the roots, stem, and leaves ( Figure 3 , Figure 4 , Figure 5 ).…”

Three rice nicotianamine synthase genes, OsNAS1, OsNAS2, and OsNAS3 are expressed in cells involved in long‐distance transport of iron and differentially regulated by iron

“…Companion cells produce and supply NA (Figure 6) to transport Fe via phloem (pH 7.8–8.0), under which conditions Fe(III)–NA is more stable than Fe(III)–DMA or Fe(III)–citrate (von Wirén et al ., 1999). In the NA‐defective mutant chloronerva , Fe accumulates in the shoot apoplasm (Scholz et al ., 1992; Yoshimura et al ., 2000), and grafting a chloronerva shoot to the wild type restored chlorosis (Rudolph and Scholz, 1972). Based on our results, it is possible that to translocate Fe within the tomato plant, the NAS gene CLN is expressed in the pericycle and companion cells of the roots and in the vascular bundles of leaves.…”

A rice FRD3-like (OsFRDL1) gene is expressed in the cells involved in long-distance transport

“…The metal transporters LelRTI and LeNRAMPI were up-regulated, even under Fe-sufficient conditions (Bereczky et al 2003). Fe in the chloronerva leaf vein is in the ferric form; the lack of NA caused a reduced amount of ferrous iron in the veins (Yoshimura et al 2000). NA prevents ferric iron from precipitating in the xylem by stable chelation (von Wiren et al 1999).…”

Application of NanoSIMS and isotopic labeling to analyze the spatial distribution of the plant iron chelator nicotianamine

“…When applying NA, these differences between chln and WT disappeared, suggesting that NA is necessary to solubilize and utilize the apoplastic Fe. X-ray Absorption Near-edge Structure (XANES) also showed that the presence of ferrous Fe was lower in the chln leaf veins than in WT or interveinal areas, suggesting that NA may be involved in maintaining Fe in the ferrous form in the veins of tomato leaves ( 40 ). In agreement, Fe localization was mainly observed in the vasculature of the roots, stem, and leaves ( Figure 3 , Figure 4 , Figure 5 ).…”

Three rice nicotianamine synthase genes, OsNAS1, OsNAS2, and OsNAS3 are expressed in cells involved in long‐distance transport of iron and differentially regulated by iron

“…Companion cells produce and supply NA (Figure 6) to transport Fe via phloem (pH 7.8–8.0), under which conditions Fe(III)–NA is more stable than Fe(III)–DMA or Fe(III)–citrate (von Wirén et al ., 1999). In the NA‐defective mutant chloronerva , Fe accumulates in the shoot apoplasm (Scholz et al ., 1992; Yoshimura et al ., 2000), and grafting a chloronerva shoot to the wild type restored chlorosis (Rudolph and Scholz, 1972). Based on our results, it is possible that to translocate Fe within the tomato plant, the NAS gene CLN is expressed in the pericycle and companion cells of the roots and in the vascular bundles of leaves.…”

A rice FRD3-like (OsFRDL1) gene is expressed in the cells involved in long-distance transport

“…The metal transporters LelRTI and LeNRAMPI were up-regulated, even under Fe-sufficient conditions (Bereczky et al 2003). Fe in the chloronerva leaf vein is in the ferric form; the lack of NA caused a reduced amount of ferrous iron in the veins (Yoshimura et al 2000). NA prevents ferric iron from precipitating in the xylem by stable chelation (von Wiren et al 1999).…”

Application of NanoSIMS and isotopic labeling to analyze the spatial distribution of the plant iron chelator nicotianamine

“…When applying NA, these differences between chln and WT disappeared, suggesting that NA is necessary to solubilize and utilize the apoplastic Fe. X-ray Absorption Near-edge Structure (XANES) also showed that the presence of ferrous Fe was lower in the chln leaf veins than in WT or interveinal areas, suggesting that NA may be involved in maintaining Fe in the ferrous form in the veins of tomato leaves ( 40 ). In agreement, Fe localization was mainly observed in the vasculature of the roots, stem, and leaves ( Figure 3 , Figure 4 , Figure 5 ).…”

Three rice nicotianamine synthase genes, OsNAS1, OsNAS2, and OsNAS3 are expressed in cells involved in long‐distance transport of iron and differentially regulated by iron

“…Companion cells produce and supply NA (Figure 6) to transport Fe via phloem (pH 7.8–8.0), under which conditions Fe(III)–NA is more stable than Fe(III)–DMA or Fe(III)–citrate (von Wirén et al ., 1999). In the NA‐defective mutant chloronerva , Fe accumulates in the shoot apoplasm (Scholz et al ., 1992; Yoshimura et al ., 2000), and grafting a chloronerva shoot to the wild type restored chlorosis (Rudolph and Scholz, 1972). Based on our results, it is possible that to translocate Fe within the tomato plant, the NAS gene CLN is expressed in the pericycle and companion cells of the roots and in the vascular bundles of leaves.…”

A rice FRD3-like (OsFRDL1) gene is expressed in the cells involved in long-distance transport

“…The metal transporters LelRTI and LeNRAMPI were up-regulated, even under Fe-sufficient conditions (Bereczky et al 2003). Fe in the chloronerva leaf vein is in the ferric form; the lack of NA caused a reduced amount of ferrous iron in the veins (Yoshimura et al 2000). NA prevents ferric iron from precipitating in the xylem by stable chelation (von Wiren et al 1999).…”