Investigators from Boyce Thompson Institute (BTI) and Cornell have successfully identified genes that could help plant breeders develop drought-resistant fruit. According to the study, some positive effects can be associated with mild water stress.

“We can now begin to select candidate genes that could help breeders develop fruit that can adapt to drought conditions, and not just tomatoes but also grapes, apples and fleshy fruit in general. That is a long-term potential application of this data,” said Carmen Catalá, an assistant professor at BTI and the senior research associate leading the study.

The researchers looked at gene expression in tomato leaves and six fruit organs at two different timepoints (growing and ripe fruit) and under four different water stress conditions (none, mild, intermediate and strong).

“When we sowed the seeds from treated plants, we found that the seedlings from stressed tomatoes showed improved recovery from water stress in comparison to seedlings from control tomatoes,” said Philippe Nicolas, a postdoctoral researcher in Catalá’s lab.

The investigation found that each of the fruit organ tissues changed in unique ways over time. In some cases, water stress can increase the amount of lycopene in ripe fruit, which is an antioxidant that has documented health benefits.

Drought-exposed fruit also had higher levels of starch biosynthesis, which could yield sweeter tomatoes.

This is the first study to build a comprehensive picture of how a fruit’s gene expression changes in response to water stress.