Novel Genetic Mechanism Controlled by Leaf Microbiota

A recent investigation has uncovered a genetic network within plants that regulates the growth of individual leaves and enables adaptation to environmental conditions. This discovery holds the potential for creating crops with enhanced drought tolerance.

Researchers at the University of Nottingham’s School of Biosciences examined maize leaf development in plants grown in three distinct soil types, each with varying levels of nutrients and water.

Their analysis revealed that microorganisms inhabiting plant leaves across these different soils affect leaf growth, irrespective of nutrient levels and soil characteristics. These results were published in the journal Cell, Host, and Microbe.

Leaves, crucial organs for plants, facilitate food production via photosynthesis. They are inhabited by microbial communities essential for plant health and survival, especially under drought conditions. This intricate microbiota aids the plant in processing necessary nutrients.

In nature, plant leaves are colonized by microbes. Whether and how these microbial communities modulate the growth of leaves is something poorly understood. We have now revealed more about this process through experiments of recolonization with synthetic communities of microbes. We demonstrated that abundant bacteria inhabiting young leaves promote individual leaf growth.”

Gabriel Castrillo, Associate Professor, School of Biosciences, University of Nottingham

The research team analyzed and sequenced RNA molecules within the leaves, revealing a genetic circuit associated with plant defense mechanisms. This circuit governs the influence of the microbiota on the growth of individual leaves.

We consider that the mechanism discovered here is responsible for balancing the growth of different leaves through differential activation of the growth-defense trade-off. We predict that this mechanism intersects with other branches of the leaf growth regulatory network to establish a hierarchy of biotic or abiotic stress responses to ensure plant survival in nature where the presence of multiple stresses is frequent.”

Gabriel Castrillo, Associate Professor, School of Biosciences, University of Nottingham

“We envision that it might now be possible to optimize endogenous growth and defense trade-off mechanisms in crops such as maize via engineering leaf microbiota to increase plant growth in poor soils without compromising the plant’s defense against pathogens,” concludes Dr. Gabriel Castrillo.