Iron homeostasis related genes in rice

Abstract

Iron is essential for plants. However, excess iron is toxic, leading to oxidative stress and decreased productivity. Therefore, plants must use finely tuned mechanisms to keep iron homeostasis in each of their organs, tissues, cells and organelles. A few of the genes involved in iron homeostasis in plants have been identified recently, and we used some of their protein sequences as queries to look for corresponding genes in the rice (Oryza sativa) genome. We have assigned possible functions to thirty-nine new rice genes. Together with four previously reported sequences, we analyzed a total of forty-three genes belonging to five known protein families: eighteen YS (Yellow Stripe), two FRO (Fe 3+ -chelate reductase oxidase), thirteen ZIP (Zinc regulated transporter / Iron regulated transporter Protein), eight NRAMP (Natural Resistance -Associated Macrophage Protein), and two Ferritin proteins. The possible cellular localization and number of potential transmembrane domains were evaluated, and phylogenetic analysis performed for each gene family. Annotation of genomic sequences was performed. The presence and number of homologues in each gene family in rice and Arabidopsis is discussed in light of the established iron acquisition strategies used by each one of these two plants.

A Plant Locus Essential for Phylloquinone (Vitamin K1) Biosynthesis Originated from a Fusion of Four Eubacterial Genes

“…The genomic sequences of the PHYLLO locus from Chlamydomonas, Populus trichocarpa, and Thalassiosira pseudonana were retrieved from genome.jgi-psf.org/euk_cur1.html, and the rice PHYLLO homologue was found in the BAC clone GenBank TM accession number AP005800. These sequences were annotated by ab initio and comparative procedures as described previously (20). For complementation analysis, the RAFL 09-32-CO5 clone was cleaved with EcoRV and SpeI, and the resulting fragment was inserted into the plant binary transformation vector pS001 (14) within compatible SmaI and XbaI restriction sites, resulting in the clone binC05.…”

Biofortified crops to alleviate micronutrient malnutrition

“…These relatively moderate gains from increased iron storage capacity most probably reflect the complex mechanisms of iron mobilization [42 ,43]. A total of 43 genes belonging to five protein families are thought to be involved in rice [44].…”

Identification and expression analysis of multiple FRO gene copies in Medicago truncatula

“…Eight other copies of the A. thaliana (At)FRO gene family have also been identified and characterized; these genes exhibit tissue-specific expression (Wu et al, 2005), although there is some discrepancy in the expression patterns of different AtFRO copies in various tissues (Mukherjee et al, 2006). Other FRO genes have been reported in plants like Pisum sativum (Waters et al, 2002), Solanum lycopersicum (Holden et al, 1991), Citrus junos (Li et al, 2002), Cucumis sativus (Waters et al, 2002), Arachis hypogaea (Ding et al, 2009), and Oryza sativa (Gross et al, 2003).…”