A subset of ABA-resistant plants may be a great source of drought-tolerant germplasm



Overlooked plants defy drought

October 4, 2016
A feature thought to make plants sensitive to drought could actually hold the key to them coping with it better, according to new findings .

Plants that are resistant to the hormone abscisic acid (ABA) have until now been understood to be bad at coping with drought. However, scientists from the Carnegie Institution for Science have discovered ABA-resistant varieties that grow better than their normal neighbours when water is scarce. 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. The team have renamed the protein ABA INSENSITIVE GROWTH 1 (ABIG1) to reflect its previously undiscovered role in preventing plant growth.

Plants with and without the protein were grown and watered for 34 days but, from day 35, water was withheld for 17 days. 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. Plants with the ABIG1 protein yellow, lose their leaves and fall over.

Read the full article: Science Daily

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Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.