RNA discovery could pump up plants’ tolerance to heat, drought and salt

SUBSCRIBE to our fortnightly e-newsletter to receive more stories like this. Thale cress, or Arabidopsis thaliana: US scientists have found a ribonucleic acid in thale cress that makes thale cress plants resistant to environmental stressors including drought and salinity.

Scientists at Texas A&M University in Dallas have found a specific ribonucleic acid (RNA) in thale cress (Arabidopsis thaliana) that can boost these plants’ resistance to key environmental stressors, including heat, drought and salt.

The scientists published their findings in Plant Physiology, an international journal devoted to the physiology, biochemistry, cellular and molecular biology, genetics, biophysics and environmental biology of plants, in September 2017

According to Texas A&M AgriLife Research associate professor and project team leader Dr Liming Xiong, their discovery could lead to the development of new drought- and salt-tolerant plants, including food crops.

“This is the first finding of a long non-coding RNA, or lncRNA, that regulates plant tolerance to adverse, non-physiological external factors,” Xiong asserts.

The research

The lncRNA that Xiong and his team discovered in thale (aka mouse-ear) cress was present in low numbers under ‘non-stress’ conditions; however, its level rose appreciably when the plants encountered stressors such as drought or high levels of salt.

When the AgriLife Research scientists upped the level of the lncRNA manually, they found corresponding increases in the thale cress plants’ tolerance to both drought and salt, compared with plants in which the levels of this lncRNA had been left unaltered.

A side-by-side comparison shows better heat and drought tolerance in thale cress plants whose level of a specific RNA was increased.
A side-by-side comparison shows better heat and drought tolerance in thale cress plants whose level of a specific RNA was increased.
Texas A&M AgriLife Research

Why explore lncRNAs?

According to Xiong, most ribonucleic acids direct or ‘code’ a plant or organism’s cell machinery to produce proteins. Non-coding RNA (ncRNA), while it doesn’t direct protein production, could affect how genetic material manifests in a myriad of other ways and is thus typically viewed as a regulator of key biological processes.

Xiong notes, however, that while small ncRNA – of which there are many different types –  have hogged scientists’ attention in recent years, longer lncRNA are potentially as or more valuable – not just to plants but to producers.

The fundamental difference between small and long non-coding RNA, Xiong explains, is the number of nucleotides they contain: lncRNA have more of these ‘building blocks’.

“In many long, or lncRNA, like the one we found to affect drought and salt tolerance in thale cress, the biological functions remain unknown,” he says.

Thale cress plant: a long non-coding (lnc) RNA isolated by Texas A&M AgriLife Research scientists in the thale or 'mouse ear' cress plant (Arabidopsis thaliana) could pave the way to developing drought, heat and salt-resistant crops.
A long non-coding (lnc) RNA isolated by Texas A&M AgriLife Research scientists in the thale or 'mouse ear' cress plant (Arabidopsis thaliana) could pave the way to developing drought, heat and salt-resistant crops.
Dean Morley, Flickr CC

The implications

Exploring lncRNA’s effects on plants’ capacity to combat environmental stress is something of a novel approach, Xiong admits. “Most of the current work on improving plant stress tolerance does not focus on lncRNA but on the genes that code protein production,” he says.

“However, manipulation of those protein-encoding genes often impairs plant growth and development.”

By contrast, Xiong’s team was able to manipulate the lncRNA in thale cress to boost its resistance to both drought and salt without any apparent harm to the plants’ health.

“It's early still, but we could be on the brink of a whole new approach to engineering drought and salt tolerance in plants, including food plants,” he says.

“Our next step will be to engineer the lncRNA levels in plants other than thale cress and to test whether it might improve drought and salt tolerance across a broader spectrum.”

Further reading

Vinegar: A cheap and simple way to help plants fight drought

More information

Read the original article: Tao Qin et al, A Nucleus-localized Long Non-Coding RNA Enhances Drought and Salt Stress Tolerance, Plant Physiology (2017). DOI: 10.1104/pp.17.00574

Contact Dr Liming Xiong via email at Liming.Xiong@ag.tamu.edu, or by phone on 1-972 952 9246.

Source: Texas A&M Agrilife 

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