Institute of Plant Nutrition, Faculty of Natural Sciences, Leibniz University Hannover, Herrenhäuser Str. 2, D-30419 Hannover, Germany.
J Exp Bot. 2011 Mar;62(6):2001-11. doi: 10.1093/jxb/erq392. Epub 2010 Dec 13.
The beneficial element silicon (Si) may affect radial oxygen loss (ROL) of rice roots depending on suberization of the exodermis and lignification of sclerenchyma. Thus, the effect of Si nutrition on the oxidation power of rice roots, suberization and lignification was examined. In addition, Si-induced alterations of the transcript levels of 265 genes related to suberin and lignin synthesis were studied by custom-made microarray and quantitative Real Time-PCR. Without Si supply, the oxidation zone of 12 cm long adventitious roots extended along the entire root length but with Si supply the oxidation zone was restricted to 5 cm behind the root tip. This pattern coincided with enhanced suberization of the exodermis and lignification of sclerenchyma by Si supply. Suberization of the exodermis started, with and without Si supply, at 4-5 cm and 8-9 cm distance from the root tip (drt), respectively. Si significantly increased transcript abundance of 12 genes, while two genes had a reduced transcript level. A gene coding for a leucine-rich repeat protein exhibited a 25-fold higher transcript level with Si nutrition. Physiological, histochemical, and molecular-biological data showing that Si has an active impact on rice root anatomy and gene transcription is presented here.
有益元素硅（Si）可能会影响水稻根的径向氧气损失（ROL），这取决于外表皮的栓化和厚壁组织的木质化。因此，研究了硅营养对水稻根氧化能力、栓化和木质化的影响。此外，通过定制的微阵列和定量实时 PCR 研究了 Si 诱导的与角质层和木质素合成相关的 265 个基因的转录水平变化。在没有 Si 供应的情况下，12cm 长不定根的氧化区沿着整个根长延伸，但有 Si 供应时，氧化区仅限于根尖后 5cm。这种模式与 Si 供应增强外表皮栓化和厚壁组织木质化相吻合。外表皮的栓化，无论是有 Si 供应还是没有 Si 供应，分别在离根尖 4-5cm 和 8-9cm 处开始。Si 显著增加了 12 个基因的转录丰度，而两个基因的转录丰度降低。一个编码富含亮氨酸重复蛋白的基因在 Si 营养条件下的转录水平提高了 25 倍。本文介绍了表明 Si 对水稻根解剖结构和基因转录具有积极影响的生理、组织化学和分子生物学数据。
