High Affinity Amino Acid Transporters Specifically Expressed in Xylem Parenchyma and Developing Seeds of Arabidopsis

Okumoto, Sakiko; Schmidt, Roberto; Tegeder, Mechthild; Fischer, W; Rentsch, Doris; Frommer, Wolf B.; Koch, Wolfgang

doi:10.1074/jbc.m207730200

Cited by 176 publications

(186 citation statements)

References 55 publications

Supporting

Mentioning

167

Contrasting

Unclassified

Order By: Relevance

“…The entries also include At1g22710, the locus of a Suc/proton symporter (AtSUC2), consistent with a previous report that its protein product is specifically located within PCC plasma membranes (Stadler and Sauer, 1996), the acidic amino acid transporters encoded by the loci At5g49630 (AAP6) and At5g09220 (AAP2; Kwart et al, 1993;Okumoto et al, 2002), and a basic amino acid permease encoded by At1g77380 (AAP3), which has been reported previously to be specifically expressed in root phloem and may function in the distribution of amino acids absorbed by the roots (Okumoto et al, 2004). Finally, the gene list also contains At1g08200, which encodes a UDP-D-apiose/UDP-D-Xyl synthase and is expressed at enhanced levels in the vasculature as visualized by promoter-reporter fusions (Mølhøj et al, 2003).…”

Section: Comprehensive Classification Of Genes Having Transcripts Thasupporting

confidence: 52%

“…This is in accord with the well-known physiological function of the phloem in amino acid transport and, by implication, represents a key molecular function for the PCCs. Within this particular classification, the acidic amino acid transporters At5g49630 and At5g09220 participate in the transport of Glu and other amino acids most important to nitrogen metabolism (Kwart et al, 1993;Okumoto et al, 2002). In particular, At5g49630 is essential for Asp transport, but previously was identified primarily in the cells of the xylem parenchyma (Okumoto et al, 2002).…”

Section: Comprehensive Classification Of Genes Having Transcripts Thamentioning

confidence: 99%

See 1 more Smart Citation

Global Characterization of Cell-Specific Gene Expression through Fluorescence-Activated Sorting of Nuclei

et al. 2008

View full text Add to dashboard Cite

We describe a simple and highly effective means for global identification of genes that are expressed within specific cell types within complex tissues. It involves transgenic expression of nuclear-targeted green fluorescent protein in a cell-type-specific manner. The fluorescent nuclei are then purified from homogenates by fluorescence-activated sorting, and the RNAs employed as targets for microarray hybridization. We demonstrate the validity of the approach through the identification of 12 genes that are selectively expressed in phloem.

show abstract

Section: Comprehensive Classification Of Genes Having Transcripts Thasupporting

confidence: 52%

Section: Comprehensive Classification Of Genes Having Transcripts Thamentioning

confidence: 99%

Global Characterization of Cell-Specific Gene Expression through Fluorescence-Activated Sorting of Nuclei

et al. 2008

View full text Add to dashboard Cite

show abstract

“…5), suggesting that vascular tissues play a key role in the perception of drought stress as well as the systemic responses. Vascular parenchyma cells have been implicated in multiple plant systemic responses, such as auxin polar transport (Galweiler et al, 1998), blue light perception (Sakamoto and Briggs, 2002), and the transport of macromolecules, minerals, and nutrients (Okumoto et al, 2002;Kataoka et al, 2004;Sunarpi et al, 2005;Lough and Lucas, 2006). Elucidation of the mechanisms that regulate stress-induced ABA biosynthesis in this cell type will be the next challenge for a full understanding of the systemic stress adaptation machinery of plants.…”

Section: Discussionmentioning

confidence: 99%

Drought Induction of Arabidopsis 9-cis-Epoxycarotenoid Dioxygenase Occurs in Vascular Parenchyma Cells

et al. 2008

View full text Add to dashboard Cite

The regulation of abscisic acid (ABA) biosynthesis is essential for plant responses to drought stress. In this study, we examined the tissue-specific localization of ABA biosynthetic enzymes in turgid and dehydrated Arabidopsis (Arabidopsis thaliana) plants using specific antibodies against 9-cis-epoxycarotenoid dioxygenase 3 (AtNCED3), AtABA2, and Arabidopsis aldehyde oxidase 3 (AAO3). Immunohistochemical analysis revealed that in turgid plants, AtABA2 and AAO3 proteins were localized in vascular parenchyma cells most abundantly at the boundary between xylem and phloem bundles, but the AtNCED3 protein was undetectable in these tissues. In water-stressed plants, AtNCED3 was detected exclusively in the vascular parenchyma cells together with AtABA2 and AAO3. In situ hybridization using the antisense probe for AtNCED3 showed that the drought-induced expression of AtNCED3 was also restricted to the vascular tissues. Expression analysis of laser-microdissected cells revealed that, among nine drought-inducible genes examined, the early induction of most genes was spatially restricted to vascular cells at 1 h and then some spread to mesophyll cells at 3 h. The spatial constraint of AtNCED3 expression in vascular tissues provides a novel insight into plant systemic response to drought stresses.

show abstract

“…Three amino acid transporters from the amino acid permease (AAP) family, AAP1, 2, and 8, are expressed in reproductive organs. In Arabidopsis siliques, AAP2 is expressed only in the vascular system, including the funiculi, AAP1 is only expressed in the seed, while AAP8 is expressed in both the vascular system and seed (Hirner et al, 1998;Okumoto et al, 2002). It has been suggested that AAP8 and AAP1 are involved in amino acid import for embryo growth or storage protein synthesis, respectively (Hirner et al, 1998;Schmidt et al, 2007).…”

Section: Nitrate (Nomentioning

confidence: 99%

Characterization of theArabidopsisNitrate Transporter NRT1.6 Reveals a Role of Nitrate in Early Embryo Development

2008

View full text Add to dashboard Cite

This study of the Arabidopsis thaliana nitrate transporter NRT1.6 indicated that nitrate is important for early embryo development. Functional analysis of cDNA-injected Xenopus laevis oocytes showed that NRT1.6 is a low-affinity nitrate transporter and does not transport dipeptides. RT-PCR, in situ hybridization, and b-glucuronidase reporter gene analysis showed that expression of NRT1.6 is only detectable in reproductive tissue (the vascular tissue of the silique and funiculus) and that expression increases immediately after pollination, suggesting that NRT1.6 is involved in delivering nitrate from maternal tissue to the developing embryo. In nrt1.6 mutants, the amount of nitrate accumulated in mature seeds was reduced and the seed abortion rate increased. In the mutants, abnormalities (i.e., excessive cell division and loss of turgidity), were found mainly in the suspensor cells at the one-or two-cell stages of embryo development. The phenotype of the nrt1.6 mutants revealed a novel role of nitrate in early embryo development. Interestingly, the seed abortion rate of the mutant was reduced when grown under N-deficient conditions, suggesting that nitrate requirements in early embryo development can be modulated in response to external nitrogen changes.

show abstract

High Affinity Amino Acid Transporters Specifically Expressed in Xylem Parenchyma and Developing Seeds of Arabidopsis

Cited by 176 publications

References 55 publications

Global Characterization of Cell-Specific Gene Expression through Fluorescence-Activated Sorting of Nuclei

Global Characterization of Cell-Specific Gene Expression through Fluorescence-Activated Sorting of Nuclei

Drought Induction of Arabidopsis 9-cis-Epoxycarotenoid Dioxygenase Occurs in Vascular Parenchyma Cells

Characterization of theArabidopsisNitrate Transporter NRT1.6 Reveals a Role of Nitrate in Early Embryo Development

Contact Info

Product

Resources

About