Improvement of nitrate- and nitrite-dependent growth of rice by the introduction of a constitutively expressing chloroplastic nitrite transporter
Loading of cytosolic nitrite into the chloroplast in nitrate assimilation of rice was modified by introducing a gene for chloroplastic nitrite transport from cucumber. Rice (<i>Oryza sativa</i> L. japonica cv. Nipponbare) was transformed with a cDNA (<i>CsNitr1-L</i>) that encodes a nitrite transporter of cucumber under the control of the <i>CaMV35S</i> promoter. <i>CsNitr1-L</i> transgenic rice grown by hydroponics with nitrate supplied as the sole nitrogen source grew as well as plants grown with ammonia. In contrast the growth of the untransformed or mock-transformed control rice was retarded on a nitrate-containing medium by about 60% compared to plants grown with ammonia. Nitrite was not beneficial to the growth of the untransformed or mock-transformed control rice but sustained that of <i>CsNitr1-L</i> transgenic rice. Low steady-state concentration of nitrite in leaves as well as delayed non-photochemical quenching of chlorophyll fluorescence in <i>CsNitr1-L</i> transgenic rice seems indicative of higher nitrite use in chloroplasts.
- Plant biotechnology
Plant biotechnology 23(1), 47-54, 2006-03-01
Japanese Society for Plant Cell and Molecular Biology