A secret bacteria component can protect our crops against climate change   

Bacteria can boost photosynthesis in plants

In their research, the UOL team mentions that photosynthesis (the natural process that allows plants to make their food using sunlight) in plants is limited by an enzyme called Rubisco. Also known as Ribulose-1,5-bisphosphate carboxylase-oxygenase, it is the most exuberant protein found in a plant’s chloroplasts — the cell organelles that conduct photosynthesis. 

Rubisco converts atmospheric carbon dioxide assimilated by a plant into useful carbon and facilitates the production of energy from CO2. It plays a crucial role in a plant’s carbon fixation stage of photosynthesis and oxygen metabolism. 

Studies in the past have shown that climate conditions like drought, increasing CO2 levels in the environment, and rising temperature adversely affect Rubisco activity. As a result, less energy is available to the plants, and food production decreases. 

During their study, the UOL researchers found that some bacteria have “CO2-concentrating mechanisms” which can improve Rubisco efficiency. This mechanism is supported by the presence of special protein microcompartments called carboxysomes in the bacteria. 

For a long time, scientists have been trying to use carboxysomes from bacteria to supply large amounts of CO2 around Rubisco in plants as this process is known to boost photosynthesis and crop production. 

The researchers claim that the current study has accomplished this feat. During the research, they successfully derived a set of carboxysomes from the bacteria Halothiobacillus neapolitanus and transferred those into the chloroplasts of a tobacco plant. 

The engineered carboxysomes enhanced Rubisco’s ability to produce energy from carbon dioxide and improved the plant’s ability to survive in adverse conditions. “We are extremely excited with this breakthrough,” said Lu-Ning Liu, one of the study authors and a microbiology expert at UOL

“Overall, our findings provide proof-of-concept for a route to improving crop development and production that can withstand changing climates and meet the growing food requirements of the world’s expanding population,” he added further.

A shocking report from the United Nations reveals that every 24 hours, our world witnesses the death of about 25,000 people only because of hunger-related issues (i.e. more than nine people every year). 

The situation may get worse, if we failed to protect our crops against climate change. Hopefully, this research work will help farmers across the globe increase their crop production so that food security can be ensured for everyone in the future.

The study is published in the journal Nature. 

Study Abstract:

The growth in world population, climate change, and resource scarcity necessitate a sustainable increase in crop productivity. Photosynthesis in major crops is limited by the inefficiency of the key CO2-fixing enzyme Rubisco, owing to its low carboxylation rate and poor ability to discriminate between CO2 and O2. In cyanobacteria and proteobacteria, carboxysomes function as the central CO2-fixing organelles that elevate CO2 levels around encapsulated Rubisco to enhance carboxylation. There is growing interest in engineering carboxysomes into crop chloroplasts as a potential route for improving photosynthesis and crop yields. Here, we generate morphologically correct carboxysomes in tobacco chloroplasts by transforming nine carboxysome genetic components derived from a proteobacterium. The chloroplast-expressed carboxysomes display a structural and functional integrity comparable to native carboxysomes and support autotrophic growth and photosynthesis of the transplastomic plants at elevated CO2. Our study provides proof-of-concept for a route to engineering fully functional CO2- fixing modules and entire CO2-concentrating mechanisms into chloroplasts to improve crop photosynthesis and productivity.