Metal accumulation in seeds is a prerequisite for germination and establishment of plants but also for micronutrient delivery to humans. To investigate metal transport processes and their interactions in seeds, we focused on METAL TOLERANCE PROTEIN8 (MTP8), a tonoplast transporter of the manganese (Mn) subclade of cation diffusion facilitators, which in Arabidopsis (Arabidopsis thaliana) is expressed in embryos of seeds. The x-ray fluorescence imaging showed that expression of MTP8 was responsible for Mn localization in subepidermal cells on the abaxial side of the cotyledons and in cortical cells of the hypocotyl. Accordingly, under low Mn availability, MTP8 increased seed stores of Mn, required for efficient seed germination. In mutant embryos lacking expression ofVACUOLAR IRON TRANSPORTER1(VIT1), MTP8 built up iron (Fe) hotspots inMTP8-expressing cells types, suggesting that MTP8 transports Fe in addition to Mn. Inmtp8 vit1double mutant seeds, Mn and Fe were distributed in all cell types of the embryo. An Fe transport function of MTP8 was confirmed by its ability to complement Fe hypersensitivity of a yeast mutant defective in vacuolar Fe transport. Imbibingmtp8-1mutant seeds in the presence of Mn or subjecting seeds to wet-dry cycles showed that MTP8 conferred Mn tolerance. During germination, MTP8 promoted reallocation of Fe from the vasculature. These results indicate that cell type-specific accumulation of Mn and Fe in seeds depends on MTP8 and that this transporter plays an important role in the generation of seed metal stores as well as for metal homeostasis and germination efficiency under challenging environmental conditions.

• MeSH
• Arabidopsis embryologie   genetika   metabolismus   MeSH
• biologické modely MeSH
• genový knockout MeSH
• homeostáza * MeSH
• klíčení * genetika   MeSH
• mangan metabolismus   MeSH
• mutace genetika   MeSH
• promotorové oblasti (genetika) genetika   MeSH
• proteiny huseníčku metabolismus   MeSH
• proteiny přenášející kationty metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• Saccharomyces cerevisiae metabolismus   MeSH
• semena rostlinná embryologie   genetika   MeSH
• spektrometrie rentgenová emisní MeSH
• testy genetické komplementace MeSH
• vývojová regulace genové exprese MeSH
• železo metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH