Modifying photosynthesis has been increasingly a research target to improve crop yields to feed a growing global population due to climate change and other environmental factors. In a recent study published in Journal of Experimental Botany, A team from the Australian National University (ANU) investigated the effects of increasing the amount of carbon dioxide channels in plant membranes, but the models could not detect any effect on photosynthesis in tobacco plants.
Photosynthesis depends on the supply of carbon dioxide (CO.)2) in chloroplasts within leaf cells, where it is fixed into sugars by the Rubisco enzyme. To obtain chloroplasts, CO2 Must diffuse into the leaf and through leaf mesophyll cells, crossing barriers such as cell walls and membranes. rising CO2 Diffusion through mesophyll cells into chloroplasts (called mesophyll conduction) would improve photosynthesis—increasing yields in crops as well as improving water-use efficiency.
“Our research targeted membranes in leaf cells; we wanted to know if we could make CO.2 CO. more efficient transfer by adding additional channels for2 Diffusion across cell membranes,” said RIPE researcher Dr Tory Clark, who conducted this study at ANU.
CO. to target2 Transferring to the plant cell membrane, ANU’s team increased the amount of aquaporin protein in the plasma membrane of the tobacco plants tested.
Senior author Dr. Michael Grozman explained, “Aquaporins are membrane channels that can facilitate the movement of molecules such as water and gas across the membrane. Our research confirms that the channels are localized in the leaf cell plasma membrane.”
Previous studies have established that in test systems, plasma-membrane intrinsic proteins (PIPs), a subset of plant aquaporins, contain CO2 transfer efficiencies, but there have been conflicting reports regarding their role in mesophyll conduction in the plant. “In this study, we were able to introduce more PIP aquaporin channels into the mesophyll cell membrane, but surprisingly this did not increase the conduction of CO2 Through the mesophyll cell, there is also no effect on photosynthetic rates,” Clark said.
“Plant growth and environmental conditions may play an important role in the ability of aquaporins to alter mesophyll conductance,” said Susanne von Kammerer, Professor of Molecular Plant Physiology in the Research School of Biology at ANU, who led this study with Grossmann. “Our study also used computer modeling to predict how membrane CO changes2 Permeability will affect the overall mesophyll conductance. We found that to improve overall mesophyll conductance by 20%, CO. volume of2 What would need to cross the plant cell membrane would need to be doubled.”
While improved photosynthesis was not realized in this study, this research is based on CO. Provides an increased understanding of the movement of2 From the atmosphere to the chloroplast.
“Taking on what we learned in this study, we can now focus our attention on gaining a better understanding of aquaporin function and how we can improve mesophyll conductance and photosynthesis,” Grozman said.
material provided by Carl R. Voise Institute for Genomic Biology, University of Illinois, Urbana-Champaign, Original written by Amanda Nguyen. Note: Content can be edited for style and length.