Yellow rust resistance, aflatoxins contamination, weather changes, European maize

Wheat is naturally resistant to yellow rust disease​

Controlling rust disease in wheat poses a significant challenge for the agricultural industry, but scientists remain in the dark about understanding the effects of environmental conditions on the performance of resistant-genes.

As new rust strains evolve with greater adaptation to higher temperatures, the need to understand the temperature-to-plant resistant relationship becomes even more urgent.

However researchers at the John Innes Centre have made a breakthrough and discovered certain wheat cultivars have a much higher resistance to yellow rust disease at higher temperatures, which they said could have significant implications for future breeding programmes.

The scientists carried out a series of tests on a specific wheat-strain to analysis the effects of different temperatures on the propagation of the Puccinia striiformis​ f. sp tritici​ (Pst) yellow rust disease. The results showed much more comprehension resistance to the disease than previously recorded, at both higher and lower temperatures.

One new gene was identified as having disease-resistant properties, while the actions of a second gene were more extensive than in earlier tests. This information could enable scientists to breed a more stable pathogen resistance in crops.

Source: BMC Plant Biology​​, January 8, 2014
“A change in temperature modulates defence to yellow (stripe) rust in wheat line UC1041 independently of resistance gene Yr36”​​
Authors: Ruth R M Bryant, Graham R D McGrann, Alice R Mitchell, Henk-jan Schoonbeek, Lesley A Boyd, Cristobal Uauy, Steve Dorling and Christopher J Ridout

The non-biological route to aflatoxin eradication?​

Aflatoxins are highly toxic, carcinogenic compounds that occur naturally in many crops and can have devastating effects on crop quality and yield, not to mention on public health.

Despite improved biological techniques aimed at detoxification, such as better handling, processing and storage, aflatoxin contamination still remains a serious problem and a considerable amount of resource is being used to find non-biological methods to reduce or eliminate contamination to limit the economic and health impacts.

Non-biological methods of detoxification have shown promising results in reducing or eliminating the possible contamination of aflatoxins in food and animal feed. However, a recent review said there is no single method that currently fulfils the necessary efficacy, safety and cost requirements needed for the removal of aflatoxin from contaminated agricultural products.

The review data indicated that hand and mechanical sorting might be the most effective non-biological method of detoxification in agricultural products and animals post-harvest. In addition, the application of advanced mechanical sorting may produce a better-quality, safer and more consistent product.

Source: Journal of the Science of Food and Agriculture
DOI: 10.1002/jsfa.6520​​
"A recent review of non-biological remediation of aflatoxin-contaminated crops”​
Authors: Erika D Womack, Ashli E Brown, Darrell L Sparks

Crops naturally adjust to variable weather conditions​

Scientists at Durham University and the Rothamsted Institute have discovered a new mechanism in plants and crops that regulates growth rates in adverse weather conditions and could be harnessed to increase crop yields.

When under stress, plants release a SUMO modifier protein to inhibit growth however the process can be reversed if the plant also releases the repressor gibberellen hormone. By modifying the interaction between the modifier protein and the repressor proteins the researchers believe they can remove the brakes from plant growth, leading to higher yields, even when plants are experiencing stress.

Dr Ari Sadanandom, associate director of the Durham Centre for Crop Improvement Technology, said: “What we have found is a molecular mechanism in plants which stabilizes the levels of specific proteins that restrict growth in changing environmental conditions. This mechanism works independently of the Gibberellin hormone, meaning we can use this new understanding for a novel approach to encourage the plant to grow, even when under stress.​

“If you are a farmer in the field then you don’t want your wheat to stop growing whenever it is faced with adverse conditions. If we can encourage the crops to keep growing, even when faced by adverse conditions, it could give us greater yields and lead to sustainable intensification of food production that we must achieve to meet the demands on the planet’s finite resources.”​

Source: Development Cell​​, January 13, 2014
“Small Ubiquitin-like Modifier Protein SUMO Enables Plants to Control Growth Independently of the Phytohormone Gibberellin”​
Authors: Lucio Conti, Stuart Nelis, Cunjin Zhang, Ailidh Woodcock, Ranjan Swarup, Massimo Galbiati, Chiara Tonelli, Richard Napier, Peter Hedden, Malcolm Bennett, Ari Sadanandom

European maize unaffected by climate change?​

Average temperatures are likely to increase as global warming takes hold and crops will suffer as climates become more extreme. More frequent droughts are a major concern for crop farmers, but there is perhaps less cause for concern than expected.

A recent study investigated the possible effects of different drought-stress environments on European maize yields and breeding traits, under current and future climates.

It found that stress patterns in 2050 would be almost identical to those found in current conditions. Severe water deficits during grain filling would increase from 18% to 25% however elevated carbon dioxide levels would moderate the effects of climate change on crop yields.

The study concluded that for crops exposed to the same drought-stress pattern, trait perturbation under current climates will have a similar impact on yield as that expected in future, even though the frequencies of severe drought stress will increase in future.

Source: Global Change Biology​​, Volume 20, issue 3, March 2014
“Characterizing drought stress and trait influence on maize yield under current and future conditions”​
Authors: Matthew T. Harrison, François Tardieu, Zhanshan Dong, Carlos D. Messina, Graeme L. Hammer