Genetic engineering of nitrite reductase gene improves uptake and assimilation of nitrogen dioxide by Rhaphiolepis umbellata (Thunb.) Makino
Hypocotyl sections of <i>Rhaphiolepis umbellata</i> (Thunb.) Makino were transformed by <i>Agrobacterium tumefaciens</i> bearing a binary vector pIG121-AtNiR, which contains cDNA of the nitrite reductase gene from <i>Arabidopsis thaliana</i> (<i>Atni</i>) under the control of a modified cauliflower mosaic virus 35S promoter and chimeric hygromycin phosphotransferase gene (<i>hph</i>). A 4% of the hypocotyl explants transfected with <i>Agrobacterium</i> formed hygromycin resistant adventitious shoots, and most of them rooted upon root induction treatment. The presence and expression of the introduced transgene in putative transgenic plants (12 months after transfection) were respectively confirmed by polymerase chain reaction (PCR) analysis using primers specific to <i>Atni</i> and by western blot analysis using anti NiR antibody. A total of 37 transgenic plant lines were obtained. Plants 33 months after the transfection were fumigated with 200±50 ppb <sup>15</sup>NO<sub>2</sub> under the natural light for one week in the fumigation chamber in a confined glasshouse. The amount of total nitrogen derived from NO<sub>2</sub> (reflecting uptake of NO<sub>2</sub>) and that of Kjeldahl nitrogen derived from NO<sub>2</sub> (reflecting assimilation of NO<sub>2</sub>) were determined using a mass spectrometer. One of the 9 transgenic plants tested was 1.6–2.0 times higher both in the uptake and assimilation of NO<sub>2</sub> than non-transformed wild-type ones.
- Plant biotechnology
Plant biotechnology 23(1), 111-116, 2006-03-01
Japanese Society for Plant Cell and Molecular Biology