Abstract
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.
Original language | English (US) |
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Pages (from-to) | 2504-2517 |
Number of pages | 14 |
Journal | Plant Biotechnology Journal |
Volume | 22 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2024 |
Keywords
- AtCGR3 pectin methyltransferase
- carbon isotope discrimination
- CO assimilation
- mesophyll conductance
- photosynthetic efficiency
- water use efficiency
ASJC Scopus subject areas
- Biotechnology
- Agronomy and Crop Science
- Plant Science