Was improvement of spinach growth by nano-TiO(2) treatment related to the changes of Rubisco activase?

Characterized by a photo-catalysis property, nano-anatase TiO(2) is closely related to photosynthesis of spinach. It could not only improve light absorbance, transformation from light energy to electron energy and active chemical energy, but also promote the activity of Rubiso activase of spinach. However, the relation between the activity of Rubiso activase and the growth of spinach promoted by nano-anatase TiO(2) treatment remains largely unclear. In this study, we find that the amount and the activity of Rubiso activase are obviously increased by nano-anatase TiO(2 )treatment, which led to the great promotion of Rubsico carboxylation and the high rate of photosynthesis, thus improving of spinach growth. The significant enhancement of Rubiso activase activity of nano-anatase TiO(2 )treated spinach is also accompanied by conformational changes as determined by spectroscopic analysis. But bulk TiO(2) effect is not as significant as nano-anatase TiO(2), as the grain size of nano-anatase TiO(2) (5 nm) is much smaller than that of bulk TiO(2), which entered spinach cell more easily.