Plants are factories that produce light and carbon dioxide – but parts of this complex process, called photosynthesis, are hampered by a lack of raw materials and machinery. To optimize production, scientists from the University of Essex have solved two key photosynthetic bottles to increase plant productivity by 27 percent in field conditions in the real world, according to a new study published in Natural plants. This is the third breakthrough for the research project Realizing Enhanced Photosynthetic Efficiency (RIPE); however, this photosynthetic trick has also been shown to conserve water.
“As a factory line, plants are as fast as their slowest machines,” said Patricia Lopez-Calcagno, a postdoctoral researcher at Essex, who led the work on the RIPE project. “We have identified some steps that are slower, and what we are doing is enabling these plants to build more machines to speed up these slower steps in photosynthesis.”
The RIPE Project is an international effort led by the University of Illinois to develop the most productive crops by improving the natural photosynthetic process, with solar energy used by all plants to regulate carbon dioxide in sugars that grow, develop and eventually yield . RIPE is supported by the Bill & Melinda Gates Foundation, the American Food and Agriculture Research Foundation (FFAR), and the UK Government Department for International Development (DFID).
The productivity of a factory decreases when supplies, transportation channels, and reliable machinery are limited. To discover what limits photosynthesis, researchers have modeled each of the 170 steps in this process to identify how plants can produce sugars more efficiently.
In this study, the team increased crop growth by 27 percent by solving two limitations: one in the first part of photosynthesis where plants convert light energy into chemical energy and one in the second part where carbon dioxide is fixed in sugars.
Within the two photosystems, sunlight is captured and converted into chemical energy that can be used for other processes in photosynthesis. A transport protein called plastocyanin transfers electrons to the photographic system to stimulate this process. But plastocyanin has a high affinity for its receptor protein in the photographic system, so it hangs around, failing to shut off electrical electrons back and forth effectively.
The team addressed this first bottleneck by helping plastocyanin share the load with the addition of cytochrome c6 – a more efficient transport protein that has a similar function in algae. Plastocyanine requires copper and cytochrome requires iron to function. Depending on the availability of these nutrients, algae can choose between these two transport proteins.
At the same time, the team has upgraded a photosynthetic bottle in the Calvin-Benson Cycle – where carbon dioxide is fixed to sugars – by eating the amount of a key enzyme called SBPase, borrowing additional cellular machinery from another plant species, and cyanobacteria.
By adding “cell forklifts” to electron transfer in photographic systems and “cellular machinery” for the Calvin Cycle, the team also improved the efficiency of using harvest water, or the ratio of biomass produced to water lost from the plant.
“In our field tests, we found that these plants are using less water to make more biomass,” said lead investigator Christine Raines, a professor at the Essex School of Life Sciences, where she also serves as Vice Chancellor. for Research. “The mechanism responsible for this additional improvement is not yet clear, but we are continuing to research this to help us understand why and how it works.”
These two improvements, when combined, have been shown to increase crop productivity by 52 percent in the greenhouse. Most importantly, this study showed up to a 27 percent increase in crop growth in field trials, which is true evidence of any crop improvement – demonstrating that these photosynthetic tapes can increase crop production in growth conditions in the world.
“This study offers the exciting opportunity to potentially combine three proven and independent methods to achieve a 20 percent increase in plant productivity,” said RIPE Director Stephen Long, Ikenberry Endowed President University of Plant Sciences and Plant Biology at the Institute Carl R. Woese for Genomic Biology in Illinois. “Our modeling suggests that combining this progress with two previous discoveries from the RIPE project could result in additional yield gains of up to 50 to 60 percent in crop crops.”
The first discovery of RIPE, published in science, helped plants adapt to changing light conditions to increase yields by up to 20 percent. The second breakthrough of the project, also published in science, created a shortcut to how plants deal with a glitch in photosynthesis to increase productivity by 20 to 40 percent.
Next, the team plans to translate these findings from tobacco – a model crop used in this study as a testing ground for genetic improvement because it is easy to engineer, grow and test – to create food crops such as cassava, cows, corn, soybeans and rice that are needed to feed our growing population this century. The RIPE project and its sponsors are committed to providing Global Access and making project technologies available to farmers who need them most.
Increase soy yields by adapting photosynthesis to the flying shadows, according to the pattern
Johannes Kromdijk et al., Improving plant photosynthesis and productivity by accelerating recovery from photoprotection, science (2016). DOI: 10.1126 / science.aai8878
Provided by the University of Illinois at Urbana-Champaign
citation: Third Progress Shows Photosynthetic Hacks Can Increase Yield, Conserve Water (2020, August 10) Retrieved August 10, 2020 from https://phys.org/news/2020-08-breakthrough-photosynthetic-hacks-boost-yield .html
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