Rothamsted Research

where knowledge grows

On the surface: genes identified that give wheat and barley their matte appearance

Banner

Glossy and matte varieties of wheat

Researchers find cluster of genes responsible for the matte, bluish-grey colour of cultivated wheat and barley.

In young plants, you can sometimes distinguish cultivated wheat varieties from wild species by their colour. Wild wheat appears either glossy green or a matte bluish-grey, but cultivated varieties are almost always the latter. The bluish-grey colour comes from a waxy film thought to increase yields and protect the plant from environmental stress, particularly drought and diseases. The genes that produce the coating have long eluded researchers, but work by an international team has now revealed them. The team was led by the Weizmann Institute in Israel, and includes scientists at Rothamsted Research, which receives strategic funding from the BBSRC. The findings, reported recently in The Plant Cell, may in the future be used to impart sturdiness to crops.

The bluish-grey coating appears only at certain stages in plant growth or in certain organs, reinforcing the idea that it helps to defend the plant. Identifying the genes involved in creating the coating has been difficult, however, as the wheat genome contains multiple sets of chromosomes and repeated copies of some of the genes. The scientists looked at the genomes of two different types of wheat: glossy-green and bluish-grey. They compared gene activity in these two wheat types using various methods, including next-generation RNA sequencing technology, which can simultaneously measure the expression of vast numbers of genes. The team also made use of the full readout of the wheat genome, sequenced recently.

The team found a cluster of three genes involved in creating beta-diketone—a waxy compound responsible for most of the bluish-grey coating. To confirm their findings, the scientist silenced the newly identified genes using genetic engineering, and showed that seeds from bluish-grey plants grew to become glossy green. They then deciphered the chain of biochemical reactions that leads to beta-diketone synthesis, including the genes and enzymes involved. Next, the scientists repeated the same research with barley, which also has a bluish-grey coating. They found that in barley, the same metabolic gene cluster and biochemical reactions are responsible for the synthesis of beta-diketone as in wheat.

Dr Kostya Kanyuka, plant pathologist at Rothamsted Research, said: “Improving wheat yield, quality and resilience to environmental stresses is one of our Institute’s core strategic research programmes. A few years ago we established a technology called virus-induced gene silencing (or VIGS) to identify wheat genes that defend against fungal pathogens and understand their functions. We were thrilled to use this technology to learn about the wheat genes involved in producing plant surface waxes.”

These findings may one day allow us to breed crops with a higher yield and a greater resistance to drought and pathogens. For instance, it might be possible to introduce the beta-dikotene genes derived from wheat into cucumber or tomato plants. As a result, whatever these plants will lose in brightness, they will gain in sturdiness.

Dr Kanyuka, who leads the wheat functional genomics team, added: “Leaf surface waxes are very important as they reduce water loss and therefore contribute to higher yields during droughts.  Moreover, these secondary metabolites represent the first line of defence against pathogens and pests. Although the composition of surface waxes and some of the genes involved in producing them have been known since the early 1960s, molecular understanding of this pathway has remained a mystery until now.”

This project was a collaborative effort between the Weizmann Institute of Science, Tel-Aviv University, the University of British Columbia, and Rothamsted Research and the John Innes Centre, both in the United Kingdom.

Contacts

Breeding oilseed rape varieties for pollinator-friendly traits

Amounts and sugar content of nectar vary between commercial varieties of oilseed rape (OSR) produced with different breeding systems, when tested in the glasshouse.

Black-grass requires a ‘three-pronged’ attack

Black-grass requires a three-pronged attack to promote and develop sustainable management solutions.

Mineral vital to human health will decrease due to climate change

New model developed to understand the variation in selenium concentrations in soil finds climate is key to its global distribution.

Rothamsted Research Celebrates £2,500 gift from the Patron's Fund

Charitable fund acknowledges the work of the charitable organisations for which Her Majesty, The Queen acts as a Patron.

Pages

Rothamsted Press Office

For further information, please contact:

Dr Matina Tsalavouta (matina.tsalavouta@rothamsted.ac.uk), Tel: +44 (0) 1582 938 525

About Rothamsted Research

We are the longest running agricultural research station in the world, providing cutting-edge science and innovation for over 170 years. Our mission is to deliver the knowledge and new practices to increase crop productivity and quality and to develop environmentally sustainable solutions for food and energy production.

Our strength lies in the integrated, multidisciplinary approach to research in plant, insect and soil science.

Rothamsted Research is strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC). In 2013-2014 Rothamsted Researched received a total of £32.9M from the BBSRC.

About BBSRC

The Biotechnology and Biological Sciences Research Council (BBSRC) invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.

Funded by Government, BBSRC invested over £509M in world-class bioscience in 2014-15. We support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.

For more information about BBSRC, our science and our impact see: http://www.bbsrc.ac.uk

For more information about BBSRC strategically funded institutes see: http://www.bbsrc.ac.uk/institutes