@article{oai:repo.qst.go.jp:00046556,
 author = {Kobayashi, Natsuko and Iwata, Naoko and Saito, Takayuki and Suzuki, Hisashi and Iwata, Ren and Tanoi, Keitaro and Nakanishi, Tomoko and 斉藤 貴之 and 鈴木 寿 and 岩田 錬 and 田野井 慶太朗 and 中西 友子},
 issue = {2},
 journal = {Soil Science and Plant Nutrition},
 month = {Feb},
 note = {We characterized magnesium (Mg) uptake and transport along the primary root of six-day-old rice seedlings
(Oryza sativa L. cv. Nipponbare) using 28Mg as a radioactive tracer. We used a multi-compartment transport
box, which separated the root region every 1 cm in order to apply 28Mg to a particular root region. Then, the
root region was defined as R-A, R-B, and R-C in order from the root tip region to the lateral root-developing
area. The amount of 28Mg taken up in the R-C region in 15 min, 1 h, and 3 h was nearly three times as much
as that of R-A and R-B. Thirty percent to 50% of 28Mg absorbed from R-C was transported toward the lower
part of the root. Furthermore, when 28Mg was absorbed from R-C, it was detected only in the root part lower
than R-C after 5 min. In contrast, less than 5% of 28Mg absorbed from R-B was transported downward.
This characteristic uptake and transport behavior was not observed with 32P(phosphorus)-phosphate or
45Ca (calcium). Our results demonstrate that Mg uptake and transport activity differ between root regions
and further suggest that phloem loading of Mg occurs at R-C within minutes after uptake from the culture
solution. Then, Mg is transported toward the root tip directly without going up the shoot.
Key words: magnesium, 28Mg tracer, multi-compartment transport box, rice root, uptake and transport.},
 pages = {149--155},
 title = {Different magnesium uptake and transport activity along the rice root axis revealed by a <sup>28</sup>Mg tracer experiments},
 volume = {59},
 year = {2013}
}