Dutch researcher discovers plant stress-resistance genes

Research Lead

Researcher Shital Dixit at Wageningen University has discovered genes in rice and the model plant Arabidopsis that enhance production in dry and saline conditions. It is suggested that these could be used to genetically engineer crop plants that will thrive on marginal land.

Dixit studied the HARDY gene, found in a collection of Arabidopsis mutants. Through genetic modification, Dixit developed Arabidopsis plants in which the HARDY gene was more active. She discovered that these genetically modified plants grew better under drought stress than ordinary Arabidopsis plants, using water more efficiently. In dry conditions the modified plants were found to vapourise considerably less water while maintaining their growth.

When the soil was dry, the HARDY plants lived on and recovered after being given water. They also proved to be resistant against high saline concentrations in the soil.

Dixit then transferred the HARDY gene to rice, producing plants that are tolerant to both drought and salt. These modified rice plants also performed at least as well in optimal cultivation conditions as ordinary rice plants, breaking the generally accepted rule that plants with increased stress tolerance do not perform as well in optimal conditions as plants without tolerance. This increases the appeal of the HARDY system.

The HARDY gene encodes for a transcription factor that regulates a whole chain of genes. A plant can therefore turn an entire drought or salt tolerance mechanism on or off with a single switch. Dixit also discovered that the SHINE gene, which also encodes for a transcription factor, is capable of making rice tolerant to salt as well.

The work was carried out Plant Research International at Wageningen and was financed by the Netherlands Organisation for Scientific Research.