Tiny plants reveal big potential for boosting crop efficiency

Tiny plants reveal big potential for boosting crop efficiency
by Clarence Oxford
Los Angeles CA (SPX) Jan 07, 2025

Researchers have discovered that hornworts, a group of often-overlooked plants, possess a unique CO2-concentrating mechanism that enhances photosynthesis efficiency. This feature centers around a structure called a pyrenoid, which acts as a microscopic CO2 concentration chamber within the plant's cells. The pyrenoid is a liquid-like compartment filled with the enzyme Rubisco, responsible for capturing CO2 and converting it into sugar during photosynthesis. Specialized channels and enzymes surrounding the pyrenoid pump in CO2, saturating Rubisco with its essential substrate.

"This CO2-concentrating mechanism gives hornworts a significant advantage," said Laura Gunn, assistant professor at Cornell's School of Integrative Plant Science. "Rubisco is an infamously inefficient enzyme, so most plants waste a lot of energy dealing with its tendency to also react with oxygen. But by concentrating CO2 around Rubisco, hornworts can maximize its efficiency and minimize this wasteful 'photorespiration' process."

The research team, using advanced imaging techniques and genetic analysis, found that hornworts likely employ a simpler system to concentrate CO2 compared to algae, which require complex machinery to pump CO2 into their cells. Hornworts probably use a passive approach with fewer components. "It's like finding a simpler, more efficient engine design," explained Fay-Wei Li, associate professor at BTI and co-corresponding author of the study. "This simplicity could make it easier to engineer similar systems in other plants, like essential crops."

Implementing a comparable CO2-concentrating mechanism in crops could enhance photosynthesis by up to 60%, potentially leading to significant increases in yields without the need for additional land or resources. The study also provides insights into plant evolution, suggesting that the machinery for concentrating CO2 was present in the common ancestor of all land plants, with hornworts retaining and refining this ability over millions of years.

As challenges like climate change and food security intensify, hornworts may offer a blueprint for agricultural innovation. While further research is necessary before this natural technology can be applied to other plants, the findings indicate a promising direction for sustainable agriculture.

This research was supported by the National Science Foundation and the Triad Foundation.

Research Report:Hornworts reveal a spatial model for pyrenoid-based CO2-concentrating mechanisms in land plants