کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10884565 1079406 2013 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modelling 18O2 and 16O2 unidirectional fluxes in plants. IV: Role of conductance and laws of its regulation in C3 plants
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات مدل‌سازی و شبیه سازی
پیش نمایش صفحه اول مقاله
Modelling 18O2 and 16O2 unidirectional fluxes in plants. IV: Role of conductance and laws of its regulation in C3 plants
چکیده انگلیسی
The good fitting of experimental data of O2 and CO2 exchanges confirms the validity of the simple model. The calculation of conductance variation during the increase of external CO2 concentration reveals a linear law of regulation between external and internal CO2 concentrations. During CO2 variations, the effects of g regulation tend to maintain a higher level of oxygenation (PR) in expense of a better carboxylation (P). Contrary to CO2, the variation of O2 creates a negative feedback effect compatible with a stabilization of atmospheric O2. The regulation of g amplifies this result. The effect of light in combination with CO2 is more complex. Below 800 μmol quanta m-2 s-1 the ratio PR/P is maintained unchangeable in expense of carboxylation efficiency. Above that irradiance value, PR/P increases dramatically. It appears that the saturation curves of photosynthesis under high light could be simply due to the regulation by the conductance g and not by any biochemical or biophysical limitation. In conclusion, the regulatory effect of conductance operates in a way that it preserves the rate of photorespiration. This confirms a positive and protective role of photorespiration at the biochemical, whole plant and atmosphere levels. Since the effects of photorespiration are linked to the properties of Rubisco, they add new arguments for a co-evolution of plant and atmosphere, including the evolution of CO2 conductance.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biosystems - Volume 113, Issue 2, August 2013, Pages 115-126
نویسندگان
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