Kopittke Peter M, McKenna Brigid A, Karunakaran Chithra, Dynes James J, Arthur Zachary, Gianoncelli Alessandra, Kourousias George, Menzies Neal W, Ryan Peter R, Wang Peng, Green Kathryn, Blamey F P C
School of Agriculture and Food Sciences, The University of Queensland, BrisbaneQLD, Australia.
Canadian Light Source Inc., SaskatoonSK, Canada.
Front Plant Sci. 2017 Aug 3;8:1377. doi: 10.3389/fpls.2017.01377. eCollection 2017.
In wheat (), it is commonly assumed that Al is detoxified by the release of organic anions into the rhizosphere, but it is also possible that detoxification occurs within the apoplast and symplast of the root itself. Using Al-resistant (ET8) and Al-sensitive (ES8) near-isogenic lines of wheat, we utilized traditional and synchrotron-based approaches to provide analyses of the distribution and speciation of Al within root tissues. Some Al appeared to be complexed external to the root, in agreement with the common assumption. However, root apical tissues of ET8 accumulated four to six times more Al than ES8 when exposed to Al concentrations that reduce root elongation rate by 50% (3.5 μM Al for ES8 and 50 μM for ET8). Furthermore, analyses of ET8 root tissues indicated the likely presence of Al-malate and other forms of Al, predominantly within the apoplast. To our knowledge, this is the first time that X-ray absorption near edge structure analyses have been used to examine the speciation of Al within plant tissues. The information obtained in the present study is important in developing an understanding of the underlying physiological mode of action for improved root growth in systems with elevated soluble Al.
在小麦中，通常认为铝通过向根际释放有机阴离子而被解毒，但也有可能解毒发生在根自身的质外体和共质体内。利用小麦的抗铝（ET8）和铝敏感（ES8）近等基因系，我们采用传统方法和基于同步加速器的方法对根组织内铝的分布和形态进行了分析。一些铝似乎在根外部形成络合物，这与通常的假设一致。然而，当暴露于使根伸长率降低50%的铝浓度（ES8为3.5 μM铝，ET8为50 μM）时，ET8的根尖组织积累的铝比ES8多四到六倍。此外，对ET8根组织的分析表明，可能存在苹果酸铝和其他形式的铝，主要存在于质外体中。据我们所知，这是首次使用X射线吸收近边结构分析来研究植物组织内铝的形态。本研究中获得的信息对于理解在可溶性铝含量升高的系统中改善根系生长的潜在生理作用模式具有重要意义。
