P.F. South et al Science 363, 45 (4 Jan 2019) U of Illinois.
Synthetic glycolate metabolism pathways stimulate crop growth and productivity in the field.
     Glycolate produced by photorespiration must be processed via a long chain of chemical reactions that span four compartments in C3 plant cells.  Transforming glycolyate into useful compounds in multiple parts of the cell, which reduces the photosynthetic efficiency by up to 50%.  To enhance efficiency, South et al used genetically modified tobacco cells to confine glycolate metabolism to one cell compartment. By inserting genetic instruction into tobacco cells in only one compartment they converted glycolate there. They inserted genetic sequence pieces of algae and pumpkin DNA and genetically engineering the cells to not produce a transport protein (PLGG1) that allows glycolate to travel between cell compartments thereby preventing glycolate from taking its normal route through the cell.    
                                                                                                              large*            genetically modified tobacco cells

       back		 Four genome modifications were tried by inserting genes
from other species to alter photosynthetic glycolate metabolism.

   1.  5 genes from an E. coli glycolate oxidation pathway...
   2.  used genes forglycolate oxidase & malate synthetase 
             from plants and catalase from E. coli...
*  3.  used GLYCOLATE DEHYDROGENASE
                       & MALATE SYNTHTASE gene inserts 
*  4.  used RNAi interferences to down-regulate the native
         glycolyate transported by PLGG1 thereby reducing
         glycolate flux through native photorespiration.
            
Modification 3 along with RNA interferences (4) increased
photosynthetics productivity in field test by   > 40%.
It remains to be seen if it will be effective in other C3 crop plants.      
     
       



     

 
     t    * 3.  used GLYCOLATE DEHYDROGENASE
                                 & MALATE SYNTHTASE GENE inserts