Overlooked plants defy drought.
A feature thought to make plants sensitive to drought could actually hold the key to them coping with it better, according to new findings published in eLife.
The new research suggests breeders should explore them for "stay green" traits.
"When breeders are looking for plants able to withstand drought, they discount those resistant to ABA, but our findings show that a subset of ABA-resistant plants may be a great source of drought-tolerant germplasm," says Professor Kathryn Barton from the Carnegie Institution for Science in California.
Drought and ABA trigger several water conserving strategies in the plant: pores on the leaf close to prevent evaporation, growth is slowed and some leaves yellow and fall from the plant.
The new research identifies a protein as the agent that retards growth and causes leaves to yellow.
Un-watered plants without the crucial ABIG1 protein retain double the number of green leaves, are able to remain upright and retain a healthier root system.
Barton and colleagues hypothesize that reducing the amount of ABIG1 in the plant increases the threshold at which the plant triggers drastic water conserving measures.
Raising this threshold may be one way to breed plants that remain green and growing during short-term drought episodes.
Plants that retain their leaves are able to continue to provide nutrition from the environment to the parts of the plants that we harvest, for example to the seeds we use for food.