<strong><span style="font-size:9pt;line-height:115%;">In global change research, where modelling of CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>fluxes from plants is an important component in determining vegetation capacity to protect the climate, mechanistic-based modelling is needed when projection of future CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>absorption dynamics need to be estimated more accurately. Rubisco is the world’s most abundant protein in plants and has the job of uniquely preparing CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>for chemical reduction. Rubisco activity in the leaf,<span>  </span>described by <em>V</em></span><span style="font-size:5pt;line-height:115%;">cmax</span><span style="font-size:9pt;line-height:115%;">, can be estimated from gas exchange measurements of the initial slope of the response of CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>assimilation rate, <em>A</em>, to intercellular [CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;">]. This technique of estimation is favourable because it can avoid the uncertainties and difficulties when <em>V</em></span><span style="font-size:5pt;line-height:115%;">cmax</span><span style="font-size:9pt;line-height:115%;"><span> </span>is obtained directly by extraction and biochemical assay in artificial media. Rate of assimilation of soybean plants grown at different temperature (20/15, 25/20, and 32/27 </span><span style="font-size:5pt;line-height:115%;">o</span><span style="font-size:9pt;line-height:115%;">C day/night temperature) and [CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;">] (350 and 700 </span><span style="font-size:9pt;line-height:115%;font-family:Symbol;">m</span><span style="font-size:9pt;line-height:115%;">mol mol</span><span style="font-size:5pt;line-height:115%;">-1</span><span style="font-size:9pt;line-height:115%;">), were measured using gas exchange. The effect of wall conductance (<em>g</em></span><span style="font-size:5pt;line-height:115%;">w</span><span style="font-size:9pt;line-height:115%;">) on the parameterization of assimilations rate was observed. The temperature dependence of <em>V</em></span><span style="font-size:5pt;line-height:115%;">cmax</span><span style="font-size:9pt;line-height:115%;"><span> </span>depends strongly on wall conductance, where the shape of the curve would change significantly if finite wall conductance were included in the analysis. The implication is that it changes the values and interpretation of the temperature response of assimilation rate</span></strong>

  • TANIA JUNE Bogor Agricultural University
Keywords: <strong><span style="font-size, 9pt, line-height, 115%, ">In global change research, where modelling of CO</span><span style="font-size, 5pt, ">2</span><span style="font-size, "><span> </span>fluxes from plants is an important component in determining vegetation capacity to protect the climate, mechanistic-based modelling is needed when projection of future CO</span><span style="font-size, "><span> </span>absorption dynamics need to be estimated more accurately. Rubisco is the world’s most abundant protein in plants and has the job of uniquely preparing CO</span><span style="font-size, "><span> </span>for chemical reduction. Rubisco activity in the leaf, <span>  </span>described by <em>V</em></span><span style="font-size, ">cmax</span><span style="font-size, ">, can be estimated from gas exchange measurements of the initial slope of the response of CO</span><span style="font-size, "><span> </span>assimilation rate, <em>A</em>, to intercellular [CO</span><span style="font-size, ">]. This technique of estimation is favourable because it can avoid the uncertainties and difficulties when <em>V</em></span><span style="font-size, "><span> </span>is obtained directly by extraction and biochemical assay in artificial media. Rate of assimilation of soybean plants grown at different temperature (20/15, 25/20, and 32/27 </span><span style="font-size, ">o</span><span style="font-size, ">C day/night temperature) and [CO</span><span style="font-size, ">] (350 and 700 </span><span style="font-size, font-family, Symbol, ">m</span><span style="font-size, ">mol mol</span><span style="font-size, ">-1</span><span style="font-size, ">), were measured using gas exchange. The effect of wall conductance (<em>g</em></span><span style="font-size, ">w</span><span style="font-size, ">) on the parameterization of assimilations rate was observed. The temperature dependence of <em>V</em></span><span style="font-size, "><span> </span>depends strongly on wall conductance, where the shape of the curve would change significantly if finite wall conductance were included in the analysis. The implication is that it changes the values and interpretation of the temperature response of assimilation rate</span></strong>

Abstract

In global change research, where modelling of CO2 fluxes from plants is an important component in determining vegetation capacity to protect the climate, mechanistic-based modelling is needed when projection of future CO2 absorption dynamics need to be estimated more accurately. Rubisco is the world’s most abundant protein in plants and has the job of uniquely preparing CO2 for chemical reduction. Rubisco activity in the leaf,  described by Vcmax, can be estimated from gas exchange measurements of the initial slope of the response of CO2 assimilation rate, A, to intercellular [CO2]. This technique of estimation is favourable because it can avoid the uncertainties and difficulties when Vcmax is obtained directly by extraction and biochemical assay in artificial media. Rate of assimilation of soybean plants grown at different temperature (20/15, 25/20, and 32/27 oC day/night temperature) and [CO2] (350 and 700 mmol mol-1), were measured using gas exchange. The effect of wall conductance (gw) on the parameterization of assimilations rate was observed. The temperature dependence of Vcmax depends strongly on wall conductance, where the shape of the curve would change significantly if finite wall conductance were included in the analysis. The implication is that it changes the values and interpretation of the temperature response of assimilation rate

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Author Biography

TANIA JUNE, Bogor Agricultural University
Department of Geophysics and Meteorology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University
How to Cite
JUNET. (1). <strong><span style="font-size:9pt;line-height:115%;">In global change research, where modelling of CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>fluxes from plants is an important component in determining vegetation capacity to protect the climate, mechanistic-based modelling is needed when projection of future CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>absorption dynamics need to be estimated more accurately. Rubisco is the world’s most abundant protein in plants and has the job of uniquely preparing CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>for chemical reduction. Rubisco activity in the leaf,<span>  </span>described by <em>V</em></span><span style="font-size:5pt;line-height:115%;">cmax</span><span style="font-size:9pt;line-height:115%;">, can be estimated from gas exchange measurements of the initial slope of the response of CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;"><span> </span>assimilation rate, <em>A</em>, to intercellular [CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;">]. This technique of estimation is favourable because it can avoid the uncertainties and difficulties when <em>V</em></span><span style="font-size:5pt;line-height:115%;">cmax</span><span style="font-size:9pt;line-height:115%;"><span> </span>is obtained directly by extraction and biochemical assay in artificial media. Rate of assimilation of soybean plants grown at different temperature (20/15, 25/20, and 32/27 </span><span style="font-size:5pt;line-height:115%;">o</span><span style="font-size:9pt;line-height:115%;">C day/night temperature) and [CO</span><span style="font-size:5pt;line-height:115%;">2</span><span style="font-size:9pt;line-height:115%;">] (350 and 700 </span><span style="font-size:9pt;line-height:115%;font-family:Symbol;">m</span><span style="font-size:9pt;line-height:115%;">mol mol</span><span style="font-size:5pt;line-height:115%;">-1</span><span style="font-size:9pt;line-height:115%;">), were measured using gas exchange. The effect of wall conductance (<em>g</em></span><span style="font-size:5pt;line-height:115%;">w</span><span style="font-size:9pt;line-height:115%;">) on the parameterization of assimilations rate was observed. The temperature dependence of <em>V</em></span><span style="font-size:5pt;line-height:115%;">cmax</span><span style="font-size:9pt;line-height:115%;"><span> </span>depends strongly on wall conductance, where the shape of the curve would change significantly if finite wall conductance were included in the analysis. The implication is that it changes the values and interpretation of the temperature response of assimilation rate</span></strong&gt;. HAYATI Journal of Biosciences, 18(1), 43. https://doi.org/10.4308/hjb.18.1.43
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