Optimizing RuBP regeneration to increase photosynthetic capacity

The regeneration of RuBP is a major factor limiting photosynthesis at sub-saturating light levels. Optimizing this process by overexpressing the enzymes sedoheptulose-1,7-bisphosphatase (SBPase) and fructose-1,6-bisphosphate aldolase (FBP aldolase) is predicted to increase wheat photosynthetic capacity. With combined funding from the BBSRC and CIMMYT, transgenic lines have been produced to overexpress either SBPase or FBP aldolase in a common UK wheat cultivar and in two CIMMYT lines. Current efforts are characterizing the most promising lines – that is, with considerably more SBPase or FBP aldolase – for further studies of the effects on photosynthetic capacity.