Photosynthesis has been the key to Earth’s habitability, mainly since the evolution of oxygenic photosynthesis with the accompanying rise in atmospheric O2 starting in the Proterozoic era, around 2.5 billion years ago. The conversion of light to chemical energy allows higher life forms and the presence of reduced carbon stocks and molecular O2 provided the fossil fuels for the beginning of our industrialized society. Do you know any other purpose of photosynthesis that would benefit us?
How come using light signal emitted in this process used to quickly screen crops? So well, let’s look at it.
An international effort called Realizing Increased Photosynthetic Efficiency (RIPE) focuses to transform the crops’ ability to turn sunlight and carbon dioxide into higher yields. Scientists are inspecting thousands of plants to find out what changes to the plant’s structure or its cellular machinery could increase production. University of Illinois researchers has disclosed a new approach to estimate the photosynthetic capacity of crops to determine these top-performing traits and speed up the screening process, according to a new study in the Journal of Experimental Botany.
“Photosynthesis is the entry point for carbon dioxide to become all the things that allow plants to grow, but measuring canopy photosynthesis is really difficult,” said Carl Bernacchi, a Research Plant Physiologist for the U.S Department of Agriculture, Agricultural Research Service, who is based at Illinois’ Carl R. Woese Institute for Genomic Biology. “Most methods are time-consuming and only measure a single leaf when it’s the function of all leaves on all plants that really matters in agriculture”.
The two spectral methods used by Bernacchi’s team simultaneously are – a hyperspectral camera for scanning crops and a spectrometer used to record very detailed information about sunlight — to quickly measure a signal called Solar Induced Fluorescence (SIF) that is emitted by plants when they become ‘energy-excited’ during photosynthesis.
Hyperspectral imaging cameras produce ‘hyper-cubes’ of data, by which the spectrum at each pixel in the image is collected. Fine reflected color differences that are not observable by the human eye or even by RGB cameras are immediately identifiable by comparison of spectra between pixels. In hyperspectral imaging, the recorded spectra have ultra-fine wavelength resolution and cover a broad range of wavelengths. It also measures continuous spectral bands.
Sun-induced fluorescence (SIF) is a novel remote sensing (RS) signal for monitoring global vegetation status, encompassing its structural and functional activity from the canopy to ecosystem levels. SIF originates from the initial reactions in Photosystem (PS) II and occurs at the wavelengths in between 650 and 780 nm, with the first peak at 690 nm.
Using the SIF signal the team obtains critical insights about photosynthesis that could ultimately lead to improving crop yields. They discovered that the key part of SIF signal better correlates with photosynthetic effect. This ‘SIF yield’ accounts for only a fraction of the energy emitted as SIF by plants to the energy captured by plants in total.
“With this insight, we can use a couple of instruments in a synergistic way to make more accurate estimates, and we can make these tools and pipelines more accessible to people who are interested in advancing the translation of photosynthesis,” said Peng Fu, a postdoctoral researcher who led this work at Illinois. In this, they picked out specific bands of light that are known to be linked to SIF (and are already well understood physiologically) to better understand what hyperspectral data is actually needed to make these estimates. “However, this study suggests that much cheaper cameras could be used instead now that we know what bands of light are needed,” said Matthew Siebers, a postdoctoral researcher at Illinois.
These tools could speed up progress by orders of magnitude, said Katherine Meacham-Hensold, also a postdoctoral researcher at Illinois. “This technology is game-changing for researchers who are refining photosynthesis as a means to help realize the yields that we will need to feed humanity this century.”
RIPE is an international project which is upgrading photosynthesis to equip farmers worldwide with higher-yielding crops to ensure everyone has enough food to lead a healthy and productive life. This is supported by the Bill & Melinda Gates Foundation, the U.S Foundation for Food and Agriculture Research, and the U.K Foreign, Commonwealth & Development Office, who are committed to ensuring Global Access and making the project’s technologies available to the farmers who need them the most.
Reference: RIPE
Read another article: Is novel hybrid material a life hacker for climate protection?
Author
