Researchers announced this week that they may have figured out one of the holy grails of agricultural science – a way to reprogram plants to make them more drought-resistant.
Turns out that when plants get stressed out from a lack of water they produce a hormone called abscisic acid (ABA). This natural chemical signal impedes plant growth, controls water availability and really helps plants cope with drought and heat stress. And it does this by regulating the opening and closing of small pores called stomata covering plant leaves, thereby retaining the precious water it contains in its body.
“When water levels go down, ABA levels in turn rise, and that causes the pores on the leaf surface (stomata) to close and reduce water loss,” said botanist Sean Cutler of the University of California, Riverside, the lead scientist on this study.
“So what we did was to take an existing agrochemical that’s already being used by farmers and reprogram plants so that they respond to the chemical as if it were the hormone. When we treat these plants with the chemical, their stomata close and water use goes down.”
The new study published this week in the journal Nature shows that genetically-engineered plants can be fooled into thinking that it was ABA they were being sprayed with, when in fact it was just fungicide mimicking the naturally-occurring chemical.
“Although we’ve created this back-door strategy, it relies on making a transgenic plant (i.e. GMO) to get the response. Bringing those types of crops to farmers’ fields has its own set of challenges that take time to address,” said Cutler.
“What we have done is provide proof-of-principle for the idea, but it will take time, testing and regulatory approval before it could ever be deployed in the field.”
However, the timing of this discovery is fortuitous. With decreasing fresh water supplies, rising global temperatures and increasing populations, there is real worry among some in the scientific community that adverse environmental conditions like major droughts like California has been suffering through will become commonplace in many farming regions.
In its fourth year now, the California drought has decreased the amount of water available for crops by two-thirds. As a result, expectations are that this year about 5 per cent of viable farmland will be left dormant. The San Joaquin Valley – one of the most important farming areas in the entire United States – may end up losing a quarter of its orchards. The end affect will be felt by all of us at the grocery store, where prices will continue to rise for everything from tomatoes and lemons to almonds and wine.
While the new technique only works for tomatoes, Cutler hesitates to speculate if and how useful his engineered crops would be in a world undergoing climate change, but believes the method should be viable in all crops.
“ABA is a very ancient hormone and the underlying molecular machinery involved in eliciting its effects is also ancient and therefore present in all crop plants – at least as far as we can tell to date,” he said.
Source - https://ca.news.yahoo.com
