Tiny organisms that live in water could hold the key to increasing agricultural yields, according to a Brock University researcher.<\/p>\n
Assistant Professor of Chemistry Divya Kaur Matta and her international research team are examining photosynthesis in cyanobacteria, a single-celled organism that clumps together to form the blue-green algal blooms seen in many lakes.<\/p>\n
Photosynthesis is the process of converting sunlight \u2014 which consists of visible light, ultraviolet light and infrared radiation \u2014 into chemical energy.<\/p>\n
In a newly published paper<\/a>, Matta\u2019s team reviewed 91 studies comparing how photosynthesis occurs in four cyanobacteria species: Thermosynechococcus elongatus<\/em>, Acaryochloris marina<\/em>, Halomicronema hongdechloris<\/em> and Fischerella thermalis.<\/em><\/p>\n The wavelengths of visible light, ultraviolet light and infrared radiation vary and can change rapidly, posing a challenge for plants, bacteria and other organisms that undergo the process of photosynthesis.<\/p>\n Most plants can efficiently absorb visible light but are less able to absorb infrared radiation, which is invisible to the eye but felt as heat.<\/p>\n \u201cFar-red, infrared light is usually underused by most crops,\u201d says Matta. \u201cThese cyanobacteria show us how to grab that low-energy light under shade, in murky water or at the bottom of a crop canopy and still turn it into useful chemical energy.\u201d<\/p>\n To better understand the four cyanobacteria species\u2019 use of different wavelengths of light, the researchers focused on photosystem I (PSI), which involves the transfer of electrons in the cell by proteins and chlorophyll, the pigment that gives plants their green colour.<\/p>\n \u201cOur paper brings together what we know about four very different cyanobacteria and asks a simple question: how do they tune the same photosynthetic machine to run on different colours of light?\u201d says Chemistry master\u2019s student Jimit Patel, the review\u2019s lead author.<\/p>\n \u201cBy comparing their strategies, we start to see practical design rules for using far-red light more efficiently,\u201d he says.<\/p>\n The team found that three of the species had minor differences in their protein and chemical structures, but Acaryochloris marina <\/em>used a molecule called pheophytin as the substance aiding the transfer of electrons.<\/p>\n There are also \u201csubtle differences\u201d in the bonding of hydrogen molecules and the arrangement of water molecules, Matta says.<\/p>\n She says small, precise changes to pigments, protein environments and water networks are enough to keep electron transfer fast and efficient, providing a \u201croadmap for how nature already extends the solar spectrum.\u201d<\/p>\n These adjustments enable cyanobacteria to use low-energy, far-red light that, when replicated in plants, \u201cwill enable future crops to capture a broader range of sunlight, stay productive under shade or stress, and support more resilient, sustainable food and energy systems in a changing climate.\u201d<\/p>\n Matta says the team\u2019s review is paving the way for the next step in the research, which is to investigate the transfer of cyanobacteria photosynthetic process to crops.<\/p>\n With this knowledge, scientists could bioengineer crops and algae to grow in a wider range of environmental conditions, ultimately boosting global food security and sustainable energy production, she says.<\/p>\n As well as Matta and Patel, the research team includes Brock master\u2019s student Amen ElMasadef, Professor of Chemistry Art van der Est and researchers from India and the United States.<\/p>\n Their review, \u201cDriving Electron Transfer in Photosystem I Using Far-Red Light: Overall Perspectives<\/a>,\u201d was published Nov. 5 in the journal Plants<\/em>.<\/p>\n