TY - JOUR
T1 - Greater mesophyll conductance and leaf photosynthesis in the field through modified cell wall porosity and thickness via AtCGR3 expression in tobacco
AU - Salesse-Smith, Coralie E.
AU - Lochocki, Edward B.
AU - Doran, Lynn
AU - Haas, Benjamin E.
AU - Stutz, Samantha S.
AU - Long, Stephen P.
N1 - We thank Mike Root for the transformation and tissue culture of tobacco. We thank David Drag, Ben Harbaugh, Ben Thompson, Ron Edquilang and Andrew Wszalek for help with the maintenance of greenhouse plants, field experiment and field harvest. We also thank Noga Adar, Maddie Burke and Amanda Eggers for technical lab support. The microscopy work was carried out, in part, in the Materials Research Laboratory Central Research Facilities, University of Illinois. This work was supported by the Bill & Melinda Gates Foundation, Foundation for Food and Agriculture Research and the UK Foreign, Commonwealth & Development Office under grant no. OPP11722157, and by Bill & Melinda Gates Agricultural Innovations grant investment ID 57248.
PY - 2024/9
Y1 - 2024/9
N2 - Mesophyll conductance (gm) describes the ease with which CO2 passes from the sub-stomatal cavities of the leaf to the primary carboxylase of photosynthesis, Rubisco. Increasing gm is suggested as a means to engineer increases in photosynthesis by increasing [CO2] at Rubisco, inhibiting oxygenation and accelerating carboxylation. Here, tobacco was transgenically up-regulated with Arabidopsis Cotton Golgi-related 3 (CGR3), a gene controlling methylesterification of pectin, as a strategy to increase CO2 diffusion across the cell wall and thereby increase gm. Across three independent events in tobacco strongly expressing AtCGR3, mesophyll cell wall thickness was decreased by 7%–13%, wall porosity increased by 75% and gm measured by carbon isotope discrimination increased by 28%. Importantly, field-grown plants showed an average 8% increase in leaf photosynthetic CO2 uptake. Up-regulating CGR3 provides a new strategy for increasing gm in dicotyledonous crops, leading to higher CO2 assimilation and a potential means to sustainable crop yield improvement.
AB - Mesophyll conductance (gm) describes the ease with which CO2 passes from the sub-stomatal cavities of the leaf to the primary carboxylase of photosynthesis, Rubisco. Increasing gm is suggested as a means to engineer increases in photosynthesis by increasing [CO2] at Rubisco, inhibiting oxygenation and accelerating carboxylation. Here, tobacco was transgenically up-regulated with Arabidopsis Cotton Golgi-related 3 (CGR3), a gene controlling methylesterification of pectin, as a strategy to increase CO2 diffusion across the cell wall and thereby increase gm. Across three independent events in tobacco strongly expressing AtCGR3, mesophyll cell wall thickness was decreased by 7%–13%, wall porosity increased by 75% and gm measured by carbon isotope discrimination increased by 28%. Importantly, field-grown plants showed an average 8% increase in leaf photosynthetic CO2 uptake. Up-regulating CGR3 provides a new strategy for increasing gm in dicotyledonous crops, leading to higher CO2 assimilation and a potential means to sustainable crop yield improvement.
KW - AtCGR3 pectin methyltransferase
KW - carbon isotope discrimination
KW - CO assimilation
KW - mesophyll conductance
KW - photosynthetic efficiency
KW - water use efficiency
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U2 - 10.1111/pbi.14364
DO - 10.1111/pbi.14364
M3 - Article
C2 - 38687118
AN - SCOPUS:85192052965
SN - 1467-7644
VL - 22
SP - 2504
EP - 2517
JO - Plant Biotechnology Journal
JF - Plant Biotechnology Journal
IS - 9
ER -