Drought-resistant Crops

This article relates to The King Is Always Above the People

In the story "The Auroras," in Daniel Alarcon's collection The King is Always Above the People, one of the characters is a woman who is studying drought-resistant crops.

Jill Farrant, one of the many scientists working in the field, points out that research has become even more urgent as climate change and an increase in population have led to an untenable situation in many regions of the world, including in Africa, where most of her study focuses. Scientists like Farrant are studying the characteristics of naturally drought-resistant plants and working to transfer some of those genes to more common crops.

What properties do drought-resistant plants possess? For one thing, many of them take in carbon dioxide in the night. Most plants do this during the day, leaving their pores (stomata) open and therefore vulnerable to moisture loss. However drought-resistant plants conduct this process at night and close their pores during the day when the rate of water loss from evaporation is the highest. Drought-resistant plants might have tubers above or underground to store moisture. Succulents, because of their waxy leaves, are great examples of prime targets to mimic.

Such modifications, if applied to crops, might be able to lend themselves toward practical solutions to feed the billions of people on the planet. For example, American scientists have found that a certain variety of wheat responded to drought conditions in Texas by growing an additional layer of wax on its leaves. Seeing plant adaptation like this is encouraging. Scientists are hoping to accelerate the process by means of genetic modification.

Efforts are underway to stimulate plants to also weather other extreme conditions which lead to water drought for plants, such as increased salinity and wild temperature swings. And while such experiments might worry those concerned about genetic manipulation, Farrant says that fears are often misguided. Frequently, she says, scientists are activating dormant genes already hidden in the plant instead of introducing any new external ones. The key here would be to trigger such plant responses without stunting growth and crop production. For example, longitudinal growth of plant roots is often a response to a search for water but such a modification will have to ensure that development is not compromised above ground.

A special category of drought tolerance called desiccation resistance is under scrutiny as these "resurrection crops" have the capacity to, quite dramatically, almost come back from the dead. Scientists believe that these plants have an ability to switch off their everyday processes to an inert glass-like state for extended periods of time and then revert back to normal once water is found.

While a few successes have been reported for crops such as potato and rice, it's still too early in the game to predict how the different factors at play will work with and against each other.

Pineapples are a drought resistant crop
Makueni farmers switch from maize to drought resistant crops, courtesy of Agatha Ngotho
Xerophyta viscosa plants, dried for 25 days until less than 5% relative water content (left) and after 5 days of watering (right), courtesy of Queensland University of Technology

Filed under Nature and the Environment

This "beyond the book article" relates to The King Is Always Above the People. It originally ran in November 2017 and has been updated for the October 2018 paperback edition. Go to magazine.

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