Scientists are learning to help tomatoes beat the heat

14-Nov-2024 - Last updated on 14-Nov-2024 at 14:58 GMT

Tomatoes and aubergines grown under foil tunnels in the Jordan Desert, middle east. Image: Getty/geogif

By studying tomato varieties in exceptionally hot growing seasons, biologists at Brown University have identified the growth cycle phase when tomatoes are most vulnerable to extreme heat, as well as the mechanisms that make the plants more heat tolerant.

The discovery, detailed in a study in Current Biology, could help protect the food supply in the face of climate instability, the researchers say.

Agricultural productivity is particularly vulnerable to climate change and rising temperatures are predicted to reduce crop yields by 2.5% to 16% for every additional 1 degree Celsius of seasonal warming.

With this in mind biologists at Brown University in the US conducted a comprehensive study on heat-tolerant tomato varieties, yielding important insights into how some tomatoes can withstand extreme temperatures.

The researchers concentrated on the pollen tube growth phase of the plant reproductive cycle, which they identified as the most vulnerable period for tomatoes under heat stress.

They studied different tomato cultivars known for their ability to produce fruit in exceptionally hot growing seasons, including varieties native to the Philippines, Russia, and Mexico.

The tomatoes were grown in the Plant Environment Center at Brown University. Collaborating with scientists at the University of Arizona, they examined how heat stress affects pollen growth in tomato flowers.

Key findings

The researchers studied gene expression changes in tomato pollen when exposed to high temperatures in a petri dish and they evaluated how pollen produced by plants in optimal greenhouse conditions responded to heat stress.

They discovered that exposure to high temperatures during the pollen tube growth phase significantly limits fruit and seed production in heat-sensitive tomato cultivars compared to heat-tolerant ones.

The Tamaulipas variety of tomato, known for its heat tolerance, demonstrated enhanced pollen tube growth under high temperatures.

Implications and future directions

The researchers say their findings could lead to the development of small molecules that prime tomato pollen to withstand heat waves.

The research opens up possibilities for improving heat resilience in commercially desirable tomato varieties without altering their other qualities and the study provides a foundation for future research aimed at developing climate-resilient crops

By identifying the specific growth phase most affected by heat and the molecular mechanisms that confer heat tolerance, the study has provided valuable insights that could help in adapting various crops to climate change.

Understanding thermotolerance, or the ability of a plant to withstand extreme temperatures, is a promising strategy to address climate adaptation, said study author Mark Johnson, a professor of biology at Brown.

“Imagine if you could just make a Heinz tomato more resilient to temperature stress without affecting the flavor profile or the way people experience the tomato,” Johnson says. “That would be a great advantage.”