Hybrid Rubisco of tomato large subunits and tobacco small subunits is functional in tobacco plants.

Biogenesis of functional ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in plants requires specific assembly in the chloroplast of the imported, cytosol-synthesized small subunits (SS) with the chloroplast-made large subunits (LS). Accumulating evidence indicates that chloroplasts (plastids) generally have a low tolerance for assembling foreign or modified Rubisco. To explore Rubisco engineering, we created two lines of transplastomic tobacco plants whose rbcL gene was replaced by tomato-derived rbcL: plant LLS2 with Rubisco composed of tobacco SS and Q437R LS and plant LLS4 with a hybrid Rubisco of tobacco SS and tomato LS (representing four substitutions of Y226F, A230T, S279T and Q437R from tobacco LS).

[Effects of high temperature on grain filling and some physiological characteristic in flag leaves of hybrid rice].

The effects of high temperature on grain filling rate and some physiological indexes in flag leaves in hybrid rice Teyou 559 were studied. The results showed that chlorophyll content and superoxide dismutase (SOD) activity in flag leaves were lower significantly by high temperature stress (Figs.2A and 3A).