Different magnesium uptake and transport activity along the rice rootaxis revealed by 28Mg tracer ｅxperiments
Different magnesium uptake and transport activity along the rice rootaxis revealed by 28Mg tracer ｅxperiments
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28Mg 示踪剂实验揭示了沿水稻根轴的不同镁吸收和运输活动
DOI：
10.1080/00380768.2012.751554
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发表时间：
2013
影响因子：
2
通讯作者：
中西友子
中科院分区：
文献类型：
--
作者：
小林奈通子;岩田直子;斉藤貴之;鈴木寿;岩田練;田野井慶太朗;中西友子
研究了6天龄水稻幼苗对镁的吸收和沿主根的运输。CV。日本)使用28毫克作为放射性示踪剂。我们使用了多隔室运输箱，每隔1 cm将根部分开，以便在特定的根部区域施加28 mg。然后，从根尖区到侧根发育区，将根区定义为R-A、R-B、R-C。R-C区在15 min、1 h和3 h的摄取量是R-A和R-B的近3倍。从R-C中吸收的28 mg中有30%~50%被输送到根的下部。此外，当从R-C中吸收28 mg时，在5 分钟后仅在低于R-C的根部检测到。相反，从R-B吸收的28镁只有不到5%被向下输送。~(32)P(磷)-磷或~(45)Ca(钙)没有观察到这一特征的吸收和转运行为。我们的结果表明，不同根区对镁的吸收和运输活性不同，进一步表明韧皮部在从培养液中吸收后的几分钟内就在R-C处装载了镁。然后，镁被直接运输到根尖，而不是向上向上。
We characterized magnesium (Mg) uptake and transport along the primary root of six-day-old rice seedlings (Oryza sativaL. cv. Nipponbare) using28Mg as a radioactive tracer. We used a multi-compartment transport box, which separated the root region every 1 cm in order to apply28Mg 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 of28Mg 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% of28Mg absorbed from R-C was transported toward the lower part of the root. Furthermore, when28Mg 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% of28Mg absorbed from R-B was transported downward. This characteristic uptake and transport behavior was not observed with32P(phosphorus)-phosphate or45Ca (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.