scholarly journals Molecular Characterization of ZosmaNRT2, the Putative Sodium Dependent High-Affinity Nitrate Transporter of Zostera marina L.

2019 ◽  
Vol 20 (15) ◽  
pp. 3650 ◽  
Author(s):  
Lourdes Rubio ◽  
Jordi Díaz-García ◽  
Vítor Amorim-Silva ◽  
Alberto P. Macho ◽  
Miguel A. Botella ◽  
...  

One of the most important adaptations of seagrasses during sea colonization was the capacity to grow at the low micromolar nitrate concentrations present in the sea. In contrast to terrestrial plants that use H+ symporters for high-affinity NO3− uptake, seagrasses such as Zostera marina L. use a Na+-dependent high-affinity nitrate transporter. Interestingly, in the Z. marina genome, only one gene (Zosma70g00300.1; NRT2.1) is annotated to this function. Analysis of this sequence predicts the presence of 12 transmembrane domains, including the MFS domains of the NNP transporter family and the “nitrate signature” that appears in all members of the NNP family. Phylogenetic analysis shows that this sequence is more related to NRT2.5 than to NRT2.1, sharing a common ancestor with both monocot and dicot plants. Heterologous expression of ZosmaNRT2-GFP together with the high-affinity nitrate transporter accessory protein ZosmaNAR2 (Zosma63g00220.1) in Nicotiana benthamiana leaves displayed four-fold higher fluorescence intensity than single expression of ZosmaNRT2-GFP suggesting the stabilization of NRT2 by NAR2. ZosmaNRT2-GFP signal was present on the Hechtian-strands in the plasmolyzed cells, pointing that ZosmaNRT2 is localized on the plasma membrane and that would be stabilized by ZosmaNAR2. Taken together, these results suggest that Zosma70g00300.1 would encode a high-affinity nitrate transporter located at the plasma membrane, equivalent to NRT2.5 transporters. These molecular data, together with our previous electrophysiological results support that ZosmaNRT2 would have evolved to use Na+ as a driving ion, which might be an essential adaptation of seagrasses to colonize marine environments.

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Chunsun Gu ◽  
Aiping Song ◽  
Xiaoxue Zhang ◽  
Haibin Wang ◽  
Ting Li ◽  
...  

2009 ◽  
Vol 59 (3) ◽  
pp. 237-243 ◽  
Author(s):  
Hisato Katayama ◽  
Mari Mori ◽  
Yoko Kawamura ◽  
Toshinori Tanaka ◽  
Masashi Mori ◽  
...  

2019 ◽  
Author(s):  
Geleta Dugassa Barka ◽  
Eveline Teixeira Caixeta ◽  
Sávio Siqueira Ferreira ◽  
Laércio Zambolim

AbstractPhysiology-based differentiation of SH genes and Hemileia vastatrix races is the principal method employed for the characterization of coffee leaf rust resistance. Based on the gene-for-gene theory, nine major rust resistance genes (SH1-9) have been proposed. However, these genes have not been characterized at the molecular level. Consequently, the lack of molecular data regarding rust resistance genes or candidates is a major bottleneck in coffee breeding. To address this issue, we screened a BAC library with resistance gene analogs (RGAs), identified RGAs, characterized and explored for any SH related candidate genes. Herein, we report the identification and characterization of a gene (gene 11), which shares conserved sequences with other SH genes and displays a characteristic polymorphic allele conferring different resistance phenotypes. Furthermore, comparative analysis of the two RGAs belonging to CC-NBS-LRR revealed more intense diversifying selection in tomato and grape genomes than in coffee. For the first time, the present study has unveiled novel insights into the molecular nature of the SH genes, thereby opening new avenues for coffee rust resistance molecular breeding. The characterized candidate RGA is of particular importance for further biological function analysis in coffee.


1991 ◽  
Vol 69 (3) ◽  
pp. 369-377 ◽  
Author(s):  
Rodney A. Webb

Radiolabelled choline was taken up by tissue slices of the cestode Hymenolepis diminuta by a sodium-dependent and a sodium-independent mechansim. The sodium-dependent uptake was saturable, against a concentration gradient, displayed structural specificity, and was inhibited, in part, by hemicholinium-3. Kinetic analysis of the sodium-dependent choline uptake showed an apparent Kt = 2.0 μM and a Vmax = 0.146 pmol∙mg−1 wet weight tissue∙min−1, which is consistent with a high-affinity choline uptake (HAChU) mechanism. The rate of uptake or release of choline depended on the magnitude and direction of the sodium gradient, was diminished by high- or low-potassium, but was not chloride or sulphate dependent. A homoexchange mechanism for HAChU was not demonstrated. Evidence was obtained to suggest that HAChU or release of endogenous ACh is regulated by autoreceptors. The choline taken up by the HAChU mechanism was but slowly converted to ACh and other products.Key words: high-affinity sodium-dependent choline uptake, sodium-independent choline uptake, cestode tissue slices, choline metabolism, high-affinity choline transporter.


Hepatology ◽  
1998 ◽  
Vol 28 (2) ◽  
pp. 521-525 ◽  
Author(s):  
Simona Berardi ◽  
Bruno Stieger ◽  
Sandra Wächter ◽  
Brigitte O'Neill ◽  
Stephan Krähenbühl

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