03生物技术基地班王伟.docVIP

A Study on the Short and Long Term Effects Aluminum Exerts on Oryza Rufipogon 03生物技术基地班 王伟 生命科学学院 明凤 副教授 Abstract Oryza rufipogon or common wild rice is a close relative of Oryza sativa, the widely cultivated rice. In the short term study, by measuring the relative root elongation of seedlings treated with different aluminum (Al) concentrations, we found that O. rufipogon showed considerable tolerance or resistance to Al toxicity and experienced a dose-dependent stimulated root growth. The subsequential aniline blue and morin staining indicated that Al did have detrimental effects on the growth of O. rufipogon and accumulated in it. The quantification of the Al content via ICP-AES has also confirmed its accumulation. Therefore O. rufipogon is tolerant, rather than resistant to the Al toxicity. The DAPI staining suggested that the recorded stimulated root growth may be owing to the dominance of the enhanced cell division over other detrimental effects at an early stage. In the long term study, through suppression subtractive hybridization (SSH) and the Northern blot, the enhanced expression of the small subunit of Rubisco and a photosystem I (PSI) P700 apoprotein A1, the two important components in photosynthesis in leaves were observed. The further investigations via the assessment of the content of chlorophyll a, b, and SDSof Rubisco also suggested that the aluminum also had a regulatory effect on the photosynthesis in the leaves besides the devastating effects on the roots. Key Words Oryza rufipogon; DAPI; stimulated root growth; SSH; Rubisco Introduction Plants are continually confronted with challenges by environmental stresses, like drought, salinity, low or high temperature, flooding, pathogen, heavy metals, etc. Al is the most abundant metal in the earth’s crust, comprising about 7.45% of its mass. As many plant species are sensitive to micromolar concentrations of Al, the potential for soils to be A1 toxic is considerable. While most of A1 is bound by liga