Takahashi Misa, Konaka Daisuke, Sakamoto Atsushi, Morikawa Hiromichi
Department of Mathematical and Life Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
Z Naturforsch C J Biosci. 2005 Mar-Apr;60(3-4):279-84. doi: 10.1515/znc-2005-3-413.
In order to investigate nocturnal uptake and assimilation of NO2 by C3 and crassulacean acid metabolism (CAM) plants, they were fumigated with 4 microl l(-1) 15N-labeled nitrogen dioxide (NO2) for 8 h. The amount of NO2 and assimilation of NO2 by plants were determined by mass spectrometry and Kjeldahl-nitrogen based mass spectrometry, respectively. C3 plants such as kenaf (Hibiscus cannabinus), tobacco (Nicotiana tabacum) and ground cherry (Physalis alkekengi) showed a high uptake and assimilation during daytime as high as 1100 to 2700 ng N mg(-1) dry weight. While tobacco and ground cherry strongly reduced uptake and assimilation of NO2 during nighttime, kenaf kept high nocturnal uptake and assimilation of NO2 as high as about 1500 ng N mg(-1) dry weight. Stomatal conductance measurements indicated that there were no significant differences to account for the differences in the uptake of NO2 by tobacco and kenaf during nighttime. CAM plants such as Sedum sp., Kalanchoe blossfeldiana (kalanchoe) and Aloe arborescens exhibited nocturnal uptake and assimilation of NO2. However, the values of uptake and assimilation of NO2 both during daytime and nighttime was very low (at most about 500 ng N mg(-1) dry weight) as compared with those of above mentioned C3 plants. The present findings indicate that kenaf is an efficient phytoremediator of NO2 both during daytime and nighttime.
为了研究C3植物和景天酸代谢（CAM）植物对二氧化氮（NO2）的夜间吸收和同化情况，用4微升/升的15N标记二氧化氮对它们进行了8小时的熏蒸处理。植物对NO2的吸收量和同化量分别通过质谱分析法和凯氏定氮质谱分析法测定。洋麻（Hibiscus cannabinus）、烟草（Nicotiana tabacum）和酸浆（Physalis alkekengi）等C3植物在白天表现出较高的吸收和同化能力，高达1100至2700纳克氮/毫克干重。虽然烟草和酸浆在夜间强烈降低了对NO2的吸收和同化，但洋麻在夜间仍保持较高的吸收和同化能力，高达约1500纳克氮/毫克干重。气孔导度测量表明，烟草和洋麻在夜间对NO2吸收的差异并无显著差异可解释。景天属植物（Sedum sp.））、长寿花（Kalanchoe blossfeldiana）和木立芦荟（Aloe arborescens）等CAM植物表现出对NO2的夜间吸收和同化。然而，与上述C3植物相比，它们在白天和夜间对NO2的吸收和同化值都非常低（最高约500纳克氮/毫克干重）。目前的研究结果表明，洋麻在白天和夜间都是一种高效的NO2植物修复剂。
