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This scientist is chasing the secrets of ancient crops

Crops gone wild.

“We’ve created a kind of ‘kindergarten for plants’,” said Professor Sergey Shabala from the University of Tasmania, describing the current state of global agriculture.

“We provide them with everything they need: nutrients, water, pesticides to kill their enemies. They’ve lost their ability to be independent of humans.”

When we domesticated crops like rice, wheat, and maize, we achieved productivity far beyond that of their wild ancestors, but in the process, these plants have become entirely dependant on the luxuries of irrigation, fertiliser, and pesticides that we provide.

Crops also rely on human intervention to save them from environmental stresses, but in many parts of the world, there just aren’t enough resources to keep mitigating the damage.

So when natural disasters such as floods and droughts occur, chaos hits the kindergarten.

That’s why Shabala is investigating ways to restore the natural defences of our domesticated crops by reactivating and reintroducing a number of ancient safety mechanisms.

He’s hoping to give them back the hardiness of their wild ancestors, while retaining their new-found productivity - and it’s become a matter of global importance.

By 2050, we expect to have a global population of 9.3 billion, and from what the reports are saying, it’s not sustainable to feed all those people if we continue business as usual.

“If things continue as they have done in the past 50 years, we will lose the race, and we’ll be  unable to meet about 40 per cent of the world’s food demand. We need a major rethink in how we produce food, and that’s why we’re working on mechanisms to try to understand how plants adapt to certain environments.”

One of the key stressors Professor Shabala is focussing on is salinity – when increased salt levels in the soil prevent plants from taking up enough water to grow.

We are losing about three hectares of farmable land to salinity every minute. But it is all too hidden and passes unnoticed, despite huge penalties to crop production.

Professor Shabala has been investigating how to reactivate tiny appendages in plants called trichomes – incredibly fine, hair-like growths that sit on the surface of the leaves – so they become highly effective ‘salt bladders’.

Microscopic salt bladders up close. Credit: Professor Sergey Shabala.

Before we domesticated them, many crop species used these trichomes as safe places to deposit the excess salt they siphoned out of the soil, but over time, they’ve forgotten how to use this crucial safety net.

“Every crop has these trichomes, but they’ve lost the ability to put salt in them,” said Professor Shabala.

He thinks the trick could be to extract some transporting genes from the wild variety, and implant them into domestic crops to kick-start the process. He’s currently leading a project to test this out in quinoa crops.

If you implant the transporter that’s present in their relatives, they could learn how to use it again.

Professor Shabala is also looking at ways to combat flooding, by giving crops a faster, more effective means of detecting hypoxia – the rapid dip in available oxygen caused by an influx of water.

While scientists have known about oxygen-sensing mechanisms in mammalian cells for years, until now, no one had been able to identify them in plants.

But Professor Shabala and his team have discovered the best candidates yet for plant oxygen sensors, which could be the key to figuring out how flood-affected plants decide to either wait below the surface for human intervention, or modify their genes so they can grow up out of the floodwaters on their own.

“In contrast to a long list of candidate genes in humans, no oxygen sensors have been found in plants. But our recent work identifies some likely candidates,” said Professor Shabala.

What’s clear from Professor Shabala’s research is that if we want to continue producing enough food to sustain our burgeoning population, we need to revolutionise our way of thinking, and give our crops the ability to survive on their own once more.

We need to do something really major and step outside the box.

“If we can target these things, we really can create the ideal type of plant that is resistant to drought, flooding, and salinity, without losing productivity.”

By Bec Crew.

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