C3 carbon fixation

C3 plants cannot grow in very hot areas at today's atmospheric CO2 level (significantly depleted during hundreds of millions of years from above 5000 ppm) because RuBisCO incorporates more oxygen into RuBP as temperatures increase.

This improvement might be due to its ability to recapture CO2 produced during photorespiration, a behavior termed "carbon refixation".

The common approach involving growing a bigger bundle sheath leads down to C2 photosynthesis.

[6] C3 carbon fixation is prone to photorespiration (PR) during dehydration, accumulating toxic glycolate products.

In the 2000s scientists used computer simulation combined with an optimization algorithm to figure out what parts of the metabolic pathway may be tuned to improve photosynthesis.

In 2019, they transferred Chlamydomonas reinhardtii glycolate dehydrogenase and Cucurbita maxima malate synthase into the chloroplast of tobacco (a C3 model organism).