The impact of modifying photosystem antenna size on canopy photosynthetic efficiency—Development of a new canopy photosynthesis model scaling from metabolism to canopy level processes. (21st September 2017)

• Record Type: Journal Article
• Authors: Song, Qingfeng; Wang, Yu; Qu, Mingnan; Ort, Donald R.; Zhu, Xin‐Guang
• Is Part Of: Plant, cell and environment. Volume 40:Number 12(2017)
• Page Start: 2946
• Page End: 2957
• Publication Date: 2017-09-21
• Subjects: antenna size -- biomass -- canopy -- photosynthesis model -- photosynthetic efficiency; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.13041
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Canopy photosynthesis (Ac ) describes photosynthesis of an entire crop field and the daily and seasonal integrals of Ac positively correlate with daily and seasonal biomass production. Much effort in crop breeding has focused on improving canopy architecture and hence light distribution inside the canopy. Here, we develop a new integrated canopy photosynthesis model including canopy architecture, a ray tracing algorithm, and C3 photosynthetic metabolism to explore the option of manipulating leaf chlorophyll concentration ([Chl]) for greater Ac and nitrogen use efficiency (NUE). Model simulation results show that (a) efficiency of photosystem II increased when [Chl] was decreased by decreasing antenna size and (b) the light received by leaves at the bottom layers increased when [Chl] throughout the canopy was decreased. Furthermore, the modelling revealed a modest ~3% increase in Ac and an ~14% in NUE was accompanied when [Chl] reduced by 60%. However, if the leaf nitrogen conserved by this decrease in leaf [Chl] were to be optimally allocated to other components of photosynthesis, both Ac and NUE can be increased by over 30%. Optimizing [Chl] coupled with strategic reinvestment of conserved nitrogen is shown to have the potential to support substantial increases in Ac, biomass production, and crop yields. Abstract : Decreasing leaf chlorophyll concentration ([Chl]) by reducing photosystem antenna size can not only improve the availability of light at lower layers of a canopy but also increase the proportion of light absorbed by leaf for photochemistry. Coupling decreasing leaf chlorophyll concentration with strategic reinvestment of conserved nitrogen can lead to substantial increases in canopy photosynthetic CO2 uptake and hence crop yield potential.