The rice mitochondrial iron transporter is essential for plant growth

Abstract

In plants, iron (Fe) is essential for mitochondrial electron transport, heme, and Fe-Sulphur (Fe-S) cluster synthesis; however, plant mitochondrial Fe transporters have not been identified. Here we show, identify and characterize the rice mitochondrial Fe transporter (MIT). Based on a transfer DNA library screen, we identified a rice line showing symptoms of Fe deficiency while accumulating high shoot levels of Fe. Homozygous knockout of MIT in this line resulted in a lethal phenotype. MIT localized to the mitochondria and complemented the growth of Δmrs3Δmrs4 yeast defective in mitochondrial Fe transport. The growth of MIT-knockdown (mit-2) plants was also significantly impaired despite abundant Fe accumulation. Further, the decrease in the activity of the mitochondrial and cytosolic Fe-S enzyme, aconitase, indicated that Fe-S cluster synthesis is affected in mit-2 plants. These results indicate that MIT is a mitochondrial Fe transporter essential for rice growth and development.

Rice nicotianamine synthase localizes to particular vesicles for proper function

“…35 Fe transport into mitochondria by Mitochondrial Fe transporter (MIT) is essential for plant growth and development. 36 In our results, Fe homeostasis was disturbed in the OsNAS2-sGFP plants, but not in the NT, m6-sGFP, and m7-sGFP plants. 18 These results may suggest that NA and DMA need to be synthesized and stored in vesicles and transported to adequate compartment in the cell to prevent interferences with Fe deficiency signaling.…”

Influence of Soil Chemistry and Plant Physiology in the Phytoremediation of Cu, Mn, and Zn

“…AtHMA7 (RAN1), the first functionally characterized heavy metal ATPase, is responsible for the biogenesis of ethylene receptors by supplying Cu at the endoplasmic reticulum and also for Cu homeostasis in seedling development (Binder et al, 2010). The rice mitochondrial Fe transporter (MIT) also appears to regulate the influx of Cu, although more studies are needed to confirm this (Bashir et al, 2011). The tonoplastlocalized AtCOPT5 is important for Cu export from the vacuole and is involved in the remobilization of Cu ions (Garcia-Molina et al, 2011;Klaumann et al, 2011).…”

“…AtZIP1 probably plays a role in Mn vacuolar efflux, based on the increased sensitivity to low Mn and increased accumulation of Mn in roots in the zip1 knockout line (Milner et al, 2013). The rice Fe transporter MIT appears to play a role in Mn transport into mitochondria (Bashir et al, 2011). The mechanisms of Mn transport in the chloroplast remain unknown, despite the fact that Mn has a critical role in photosynthesis and the chloroplast is the one of the major sinks for Mn (Millaleo et al, 2013;Yao et al, 2012).…”

The Arabidopsis YELLOW STRIPE LIKE4 and 6 Transporters Control Iron Release from the Chloroplast

“…In the mitochondrion, Fe transport has been shown to involve members of the MITOCHONDRIAL SOLUTE CARRIER family, such as the MITOCHONDRIA IRON TRANSPORTER in rice (Oryza sativa; Mühlenhoff et al, 2003;Li and Kaplan, 2004;Froschauer et al, 2009;Bashir et al, 2011). More than mitochondria, plastids are high Fe-demanding organelles in plant cells, as chloroplasts contain up to 80% of the cellular Fe of leaves (Terry and Abadia, 1986).…”