Nitrate transporter gene

Hildebrand, M., and Dahlin, K. (2000b). Nitrate transporter genes from the diatom Cylindrotheca fusiformis (BaciUariophyceae) mRNA levels controUed by nitrogen source and by the ceU cycle. J. Phycol. 36, 702-713, doi 10.1046/j.l529-8817.2000.99153.x. 

It is well known that chemical compo.sition of rhizosphere solution can affect plant growth. Particularly, uptake of nutrients may be considerably influenced by the ionic concentration of the rhizosphere solution (40). Despite the difficulty of defining the exact concentration of ions in the rhizosphere surrounding each root (or even root portion), it has been unequivocally demonstrated that plants have evolved mechanisms to cope with the uneven distribution of ions in the root surrounding in order to provide adequate supply of each essential nutrient (41). These mechanisms include expression of transporter genes in specific root zones or cells and synthesis of enzymes involved in the uptake and assimilation of nutrients (40,43). Interestingly, it has been shown that specific isoforms of the H -ATPase are expressed in the plasma membrane of cell roots it has been proposed that the expression of specific isoforms in specific tissues is relevant to nutrient (nitrate) acquisition (44) and salt tolerance (45). 

Y.-F. Tsay, J. L. Schroeder, K. A. Feidmann, and N. M. Crawford, A herbicide sensitive gene CHLI of Arahidopsis encodes a nitrate-inducible nitrate transporter. Cell 72 705 (1993). 

Noji, S. Nohno, T. Saito, T. Taniguchi, S. The narK gene product participates in nitrate transport induced in Escherichia coli nitrate-respiring cells. FEBS Lett., 252, 139-143 (1989)... 

Quaggiotti, S., Reperti, B., Pizzeghello, D., Francioso, O., Tugnoli, V., and Nardi, S. (2004). Effect of low molecular size humic substances on the expression of genes involved in nitrate transport and reduction in maize (Zea mays L.). J. Exp. Bot. 55, 803-813. 

Wang, R. C., and Crawford, N. M. (1996). Genetic identification of a gene involved in constitutive, high-affinity nitrate transport in higher plants. Proc. Natl. Acad. Sci. USA 93, 9297-9301. 

Natronobacterium pharaonis, an alkaliphilic halobacterium, contains a halorhodopsin as well, though at only 10% of the level of halobium hop. The activity of pharaonis halorhodopsin in vitro is not more alkali tolerant than is halobium hop their pH dependence is similar. Unlike halobium halorhodopsin, the pharadopsin hop transports nitrate as well as it does chloride [141]. The pharaonis hop gene was cloned by probing with the gene from Halobacterium halobium, and its identity was confirmed by comparison with partial peptide sequence obtained from the purified protein [142]. 

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