The Vacuolar Manganese Transporter MTP8 Determines Tolerance to Iron Deficiency-Induced Chlorosis in Arabidopsis

Eroğlu, Seçkin
von Wiren, Nicolaus
Peiter, Edgar
Iron (Fe) deficiency is a widespread nutritional disorder on calcareous soils. To identify genes involved in the Fe deficiency response, Arabidopsis (Arabidopsis thaliana) transfer DNA insertion lines were screened on a high-pH medium with low Fe availability. This approach identified METAL TOLERANCE PROTEIN8 (MTP8), a member of the Cation Diffusion Facilitator family, as a critical determinant for the tolerance to Fe deficiency-induced chlorosis, also on soil substrate. Subcellular localization to the tonoplast, complementation of a manganese (Mn)-sensitive Saccharomyces cerevisiae yeast strain, and Mn sensitivity of mtp8 knockout mutants characterized the protein as a vacuolar Mn transporter suitable to prevent plant cells from Mn toxicity. MTP8 expression was strongly induced on low-Fe as well as high-Mn medium, which were both strictly dependent on the transcription factor FIT, indicating that high-Mn stress induces Fe deficiency. mtp8 mutants were only hypersensitive to Fe deficiency when Mn was present in the medium, which further suggested an Mn-specific role of MTP8 during Fe limitation. Under those conditions, mtp8 mutants not only translocated more Mn to the shoot than did wild-type plants but suffered in particular from critically low Fe concentrations and, hence, Fe chlorosis, although the transcriptional Fe deficiency response was up-regulated more strongly in mtp8. The diminished uptake of Fe from Mn-containing low-Fe medium by mtp8 mutants was caused by an impaired ability to boost the ferric chelate reductase activity, which is an essential process in Fe acquisition. These findings provide a mechanistic explanation for the long-known interference of Mn in Fe nutrition and define the molecular processes by which plants alleviate this antagonism.


Genetic diversity of scald (rhynchosporium secalis) disease resistant and sensitive Turkish barley seed sources as determined with simple sequence repeats
Dizkırıcı, Ayten; Kaya, Zeki; Department of Biology (2006)
Scald disease (Rhynchosporium secalis) is one of the major plant diseases causing considerable yield loss in barley (Hordeum vulgare) plantations in Turkey. To develop, scald resistant barley varieties, C.R.I.F.C. of Turkey has a large accumulated collection of barley seed sources in hand, but these samples are difficult to be followed and used in the breeding programs due to lack of genetic studies on them. Thus, the objective of this study was to characterize and fingerprint of eighty barley seed sources,...
Utilization of chestnut flour in gluten-free cakes
Demirkesen, Ilkem; Sumnu, Gulum; Şahin, Serpil (2011-12-01)
The inappropriate immune response to the certain grain proteins in wheat, barley, rye and possibly oat is called celiac disease. In order to produce gluten-free products, many scientists and manufacturers used flours obtained from different sources such as corn, soy, sorghum, buckwheat and chickpea. Furthermore, ingredients and gums such as emulsifiers, enzymes, dairy products, fibers and hydrocolloids were used to improve functional properties of gluten-free products. Chestnut flour can be a good alternati...
The Conservation of VIT1-Dependent Iron Distribution in Seeds
Eroğlu, Seçkin; Vogel-Mikus, Katarina; Kavcic, Anja; Filiz, Ertugrul; TANYOLAÇ, MUHAMMED BAHATTİN (2019-07-01)
One third of people suffer from anemia, with iron (Fe) deficiency being the most common reason. The human diet includes seeds of staple crops, which contain Fe that is poorly bioavailable. One reason for low bioavailability is that these seeds store Fe in cellular compartments that also contain antinutrients, such as phytate. Thus, several studies have focused on decreasing phytate concentrations. In theory, as an alternative approach, Fe reserves might be directed to cellular compartments that are free of ...
The effect of virus induced gene silencing of fas associated factor1 in blumeria graminis infected barley
Bozhanaj, Kreshnik; Akkaya, Mahinur S.; Department of Biotechnology (2009)
Cereal loss due to fungal pathogens is an ongoing setback in agriculture. Elucidating plant’s resistance and susceptibility mechanisms against these cereal killers, promises progress in agriculture. In the way of understanding barley resistance against fungus Blumeria Graminis we silenced FAS-Associated Factor 1 (FAF1) gene in its mRNA level with Virus Induced Gene Silencing (VIGS) technique. Previous research in our lab had shown an augmentation in mRNA levels of FAF1 gene in fungus infected wheat, suggest...
Study of bone characteristics and muscle quality in metabolic disorders
Bozkurt, Özlem; Severcan, Feride; Department of Biology (2012)
Although the effects of diabetes on bone mineral content has been studied, little is known about the structural alterations in collagen, maturation of apatite crystals and carbonate content in diabetic bone. The first part of this study aimed to investigate the mineral and organic properties of cortical, trabecular and growth plate regions of rat femur tissues in type I diabetes using FTIR microspectroscopy and Vickers microhardness test. A decrease in mineral content (degree of mineralization), decrease in...
Citation Formats
S. Eroğlu, N. von Wiren, and E. Peiter, “The Vacuolar Manganese Transporter MTP8 Determines Tolerance to Iron Deficiency-Induced Chlorosis in Arabidopsis,” PLANT PHYSIOLOGY, pp. 1030–1045, 2016, Accessed: 00, 2020. [Online]. Available: