Mechthild Tegeder

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Arabidopsis amino acid transporters (AAPs) show individual temporal and spatial expression patterns. A new amino acid transporter, AAP8 was isolated by reverse transcription-PCR. Growth and transport assays in comparison to AAP1-5 characterize AAP8 and AAP6 as high affinity amino acid transport systems from Arabidopsis. Histochemical(More)
Amino acids are regarded as the nitrogen 'currency' of plants. Amino acids can be taken up from the soil directly or synthesized from inorganic nitrogen, and then circulated in the plant via phloem and xylem. AtAAP3, a member of the Amino Acid Permease (AAP) family, is mainly expressed in root tissue, suggesting a potential role in the uptake and(More)
Amides and acidic amino acids represent the major long distance transport forms of organic nitrogen. Six amino acid permeases (AAPs) from Arabidopsis mediating transport of a wide spectrum of amino acids were isolated. AAPs are distantly related to plasma membrane amino acid transport systems N and A and to vesicular transporters such as VGAT from mammals.(More)
The anatomy of developing pea seeds is characterized by transfer cells present in both coats and cotyledons at the maternal/filial interface. To determine the nature and cellular localization of sucrose transporters in pea seeds, a full-length clone of a sucrose/H+ symporter (PsSUT1) was isolated from a cotyledon cDNA library. Northern blot analyses of(More)
Protoplasts of 10 cultivars of V. faba were isolated from etiolated shoot-tips and tested for their regeneration capacity. After purification, protoplasts were embedded in sodium alginate and cultivated in the medium of Kao and Michayluk (1975) containing 0.5 mg·1−1 of each 2,4-dichlorophenoxyacetic acid, naphthylacetic acid and 6-benzylaminopurine.(More)
To determine the nature and cellular localization of amino acid transport in pea seeds, two cDNA clones belonging to the AAP family of H(+)/amino acid co-transporters (PsAAP1 and PsAAP2) were isolated from a cotyledon cDNA library of pea (Pisum sativum L.). Functional expression in the yeast amino acid uptake mutants 22Delta6AAL and 22Delta8AA showed that(More)
During the storage phase, cotyledons of developing pea seeds are nourished by nutrients released to the seed apoplasm by their maternal seed coats. Sucrose is transported into pea cotyledons by sucrose/H+ symport mediated by PsSUT1 and possibly other sucrose symporters. PsSUT1 is principally localised to plasma membranes of cotyledon epidermal and(More)
In most plant species, amino acids are the predominant chemical forms in which nitrogen is transported. However, in nodulated tropical or subtropical legumes, ureides are the main nitrogen transport compounds. This review describes the partitioning of amino acids and ureides within the plant, and follows their movement from the location of synthesis(More)
Nitrogen is an essential macronutrient for plant growth. Following uptake from the soil or assimilation within the plant, organic nitrogen compounds are transported between organelles, from cell to cell and over long distances in support of plant metabolism and development. These translocation processes require the function of integral membrane(More)
Membrane proteins are essential to move amino acids in or out of plant cells as well as between organelles. While many putative amino acid transporters have been identified, function in nitrogen movement in plants has only been shown for a few proteins. Those studies demonstrate that import systems are fundamental in partitioning of amino acids at cellular(More)