Environmental regulation of intrinsic photosynthetic capacity: an integrated view

- Photosynthetic capacity is modulated in response to opportunity in the environment.
- Photosynthetic capacity should be evaluated on different reference bases and scales.
- Photosynthetic capacity response varies among species and ecotypes.
- Photosynthesis, sink strength, and vascular transport capacity are synchronized.
- Alternative sinks and vascular design co-optimize productivity and stress tolerance.

Environmental modulation of photosynthetic capacity is reviewed in the context of its assessment and its regulation, genetic differences among species and ecotypes, and links to plant stress tolerance and productivity. Modulation of intrinsic photosynthetic capacity matches investment in photosynthetic components to opportunity for CO2 uptake and productivity in specific environments, with exceptionally high rates during particularly narrow windows of opportunity. Response varies among species and ecotypes and should be evaluated on multiple reference bases as well as chloroplast, leaf, and whole plant scales. Photosynthetic capacity, total foliar vascular transport capacity, and plant sink strength are modulated in concert. Switching among alternative target sinks and alternative foliar vascular architectures may provide avenues for co-optimization of productivity and stress tolerance.

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