Finding genes to help fruit adapt to drought

ITHACA, NY – As climate change is expected to bring more frequent droughts, researchers are increasingly striving to make discoveries that can help plants adapt to prolonged water stress.

Researchers from the Boyce Thompson Institute and Cornell University have completed the first study to provide a comprehensive picture of gene expression changes in response to water stress in a fruit – tomato, solanum tomato – identify genes that could help plant breeders develop fruits capable of withstanding drought conditions.

Published in the December issue of Plant physiology, the work was led by the research team of Carmen Catalá, Assistant Professor at BTI and Senior Research Associate at Cornell’s School of Integrative Plant Science (SIPS). Collaborating researchers include Jocelyn Rose, a professor at SIPS, and BTI professors Jim Giovannoni, Zhangjun Fei and Lukas Mueller, who are also adjunct professors at SIPS.

“We have identified a number of genes involved in the water stress response in tomato fruit,” Catalá said. “We can now start selecting candidate genes that could help breeders develop fruits that can adapt to drought conditions, not just tomatoes but also grapes, apples and fleshy fruits in general. This is a potential long-term application of this data.

Researchers examined gene expression in tomato leaves and six fruit organs (pericarp, placenta, septum, columella, jelly, and seeds) at two different times (growing fruit and ripening fruit) and under four stress conditions. water content (none, light, medium and strong).

The researchers found that each of the fruit’s organ tissues changed in unique ways over time.

“Less than 1% of the expressed genes that were affected by water stress were shared between the six fruit tissues, and more than 50% of the affected genes were specific to a single tissue,” Catala said.

Unlike the negative effects of drought, which trigger physiological disorders and fruit loss, there are some positive effects associated with drought – at least with mild drought.

For example, researchers have found that water stress increases the amount of lycopene in ripe fruit. Lycopene is an antioxidant that has documented health benefits. Water-stressed fruits also had higher levels of starch biosynthesis, which may result in sweeter tomatoes.

The researchers also discovered that they could “train” the tomatoes to be more resistant to future water droughts.

“When we sowed the seeds of the treated plants, we found that the stressed tomato seedlings showed better recovery from water stress compared to the control tomato seedlings,” said Philippe Nicolas, postdoctoral researcher at Catalá’s lab and first author. of the item.

Nicolas said he identified several genes whose expression is induced by water stress in mature seeds, which could play an important role in conferring water stress tolerance to the next generation of plants.

The study was difficult in several ways because the researchers were looking at the fruit. Most studies of plant responses to water stress examine the roots and leaves of seedlings because they are relatively easy to study.

“It’s relatively easy to stress seedlings, but if you stress the plants too much, they won’t flower and develop fruit,” Catalá said. “Additionally, when you want to study fruit, you have to grow adult plants, which takes up more time, space, and overall resources.”

About the Boyce Thompson Institute:

Opened in 1924, the Boyce Thompson Institute is a leading life science research institution located in Ithaca, New York. BTI scientists investigate basic plant and life science research with the goal of increasing food security, improving environmental sustainability in agriculture, and making fundamental discoveries that will improve health. human. Throughout this work, BTI is committed to inspiring and educating students and providing advanced training for the next generation of scientists. BTI is an independent, not-for-profit research institute also affiliated with Cornell University. For more information, please visit BTIscience.org.

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