水稻白条纹突变体6001剑叶光合功能衰老特性研究

Senescent Characteristics of Flag Leaf Photosynthesis in a White Stripe Rice Mutant 6001

利用生理生化方法和电镜观察,对衰老过程中白条纹突变体6001剑叶光合特性进行分析。检测结果表明,该突变体抽穗期和乳熟期的叶绿素含量分别比野生型6028低34.78%和3.00%,而完熟期高于野生型;突变体的净光合速率在抽穗期较低,但在衰老过程中,特别是衰老后期净光合速率的下降显著减缓;Ca2+-ATPase和Mg2+-ATPase酶的活性和光合磷酸化活性也表现出相同的变化趋势;在整个衰老过程中类囊体膜只有68kDa多肽组分发生了明显变化,68kDa多肽组分的含量变化可能是导致光合作用变化的原因之一;电镜观察结果表明,在衰老过程中突变体的叶绿体结构更为完整,叶绿体膜解体缓慢。突变体6001在衰老过程中光合性能衰老相对缓慢,表现出抗衰老特性。

The photosynthetic performance of flag leaf in a white stripe rice mutant 6001, was analyzed by combing physiological, biochemical and electron ultramicroscope techniques during the aging process. The results of physiological and biochemical analyses showed that as compared to the wild type 6028, the chlorophyll content in mutant was 34.78%, 3.00% lower in heading and milk ripe stages, respectively, but higher in full ripening stage. Net photosynthetic rate was also lower in heading stage, but declined more slowly with aging, especially at the later period of aging. Ca2＋- ATPase/Mg2＋-ATPase enzyme activities and photophosphorylation activity also show a same trend. Only 68 kDa peptide component in the thylakoid membrane was changed significantly with aging, the change in the peptide component content might involved in the photosynthesis changes. The observation results with the electron ultramicroscope showed that, the mutant had more intact chloroplast, and the chloroplast membrane disintegrated more slowly in the process of aging. In conclusion, the slowdown of the photosynthetic senescence in the aging process suggested mutant 6001 performed a anti aging properties.