Plant and Soil Sciences eLibrary
Leaf carbon isotope composition (δ13C) has been used to screen for water-use efficiency in C3 plants, but gaps in the understanding of factors influencing δ13C have limited its application in C4 species. This study exploited maize genetic diversity to explore biochemical and post-photosynthetic factors that may influence δ13C. Our findings indicate that the observed variation in leaf carbon isotope composition across diverse maize lines is likely driven by differences in stomatal and mesophyll conductance and not photosynthetic or respiratory metabolism.
20/01/2010 · CIÊNCIAS FLORESTAIS
They found that elevated CO2 increased rates of net photosynthesis in about 85% of the reported studies, while reducing stomatal conductances and rates of transpiration in approximately 75% of the cases analyzed....
While oxygen is necessary for the process of respiration, glucose plays a crucial role in the diet; and that explains why the photosynthesis is important for all the lifeforms on the planet - including humans.