Current and possible approaches for improving photosynthetic efficiency

Abstract

One of the most important tasks laying ahead today's biotechnology is to improve crop productivity with the aim of meeting increased food and energy demands of humankind. Plant productivity depends on many genetic factors, including life cycle, harvest index, stress tolerance and photosynthetic activity. Many approaches were already tested or suggested to improve either. Limitations of photosynthesis have also been uncovered and efforts been taken to increase its efficiency. Examples include decreasing photosynthetic antennae size, 2 increasing the photosynthetically available light spectrum, countering oxygenase activity of Rubisco by implementing C4 photosynthesis to C3 plants and altering source to sink transport of metabolites. A natural and effective photosynthetic adaptation, the sugar alcohol metabolism got however remarkably little attention in the last years, despite being comparably efficient as C4, and can be considered easier to introduce to new species. We also propose root to shoot carbon-dioxide transport as a means to improve photosynthetic performance and drought tolerance at the same time. Different suggestions and successful examples are covered here for improving plant photosynthesis as well as novel perspectives are presented for future research.

Improving the Rice Photosynthetic Efficiency and Yield by Editing OsHXK1 via CRISPR/Cas9 System

“…The CO 2 concentration mechanism in C3 crop species involves making full use of the CO 2 released by photorespiration, improving the CO 2 concentration in chloroplasts, and improving the photosynthetic efficiency of those crop species. This mechanism can also simulate the improvement of the heat resistance and drought resistance of C3 crop species, resulting in favorable results with no penalty [6]. Shen et al (2019) generated a new chloroplastic photorespiratory bypass method in rice chloroplasts to alter the contents of glycolic acid, glyoxylic acid, oxalic acid, and carbon dioxide; reduce respiration; and improve photosynthetic efficiency [64].…”

“…However, thus far, photosynthesis has only slightly improved crop yields, and the levels are still far below the expected levels [5]. Previous research has shown that the factors limiting photosynthetic activity include light reactions, dark reactions, and metabolite transport from the source to sink tissue [6].…”

Cytosolic Ascorbate Peroxidases Plays a Critical Role in Photosynthesis by Modulating Reactive Oxygen Species Level in Stomatal Guard Cell

“…However, as a paradoxical result, the stomatal opening decreased, and the water loss rate should decrease, whereas the water loss rate increased in IAO lines in our study. This is mainly due to a number of factors that control the water loss rate in leaves, including stomatal opening, waxy thickness of leaf surface, and leaf epidermal cell arrangement (Zhu et al, 2010;Evans, 2013;Eva et al, 2019). The increase of VPD on the leaf surface and leaf surface temperature might be the one reason of increased water loss rate in IAO lines (Figures 3E, F).…”

“…At present, the light energy utilization rate is still very low, generally only 1-2% in crops. It is estimated that if the light energy utilization rate increased to 2.4-2.6%, the yield can reach to 1,000 kg per unit of acres in wheat and rice (Eva et al, 2019;Simkin et al, 2019). Therefore, there is great potential to improve the photosynthetic efficiency for high yield production in crops.…”

PhotoModPlus: A web server for photosynthetic protein prediction from genome neighborhood features

“…However, there is still limited information about the complexity of the photosynthetic system, and many genes and protein functions are yet to be explored. Discovering new genes/proteins in the photosynthetic process is substantially important, as it may point the way to improve photosynthesis efficiency [1][2][3][4] and its applications [5][6][7][8].…”