Login

GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]


Fighting plant disease at warm temperatures keeps food on the table

An issue of global concern is the anticipated shortage of agricultural output to meet the steady rise in human population. Michigan State University scientists understand that overcoming crop loss due to disease and adverse weather will be key in achieving this goal.

One of the best historical examples of this is the Irish Potato Famine. Beginning in 1845, Ireland experienced the "perfect storm" of unusually cool, damp weather that provided prime growing conditions for an exotic pathogen that destroyed the potato crop. With their primary food source ravaged by disease, a million Irish people died from the ensuing famine.

On the other end of the thermometer, warmer temperatures also can cause extensive crop loss. This critical correlation between changing weather and plants' ability to fend off diseases is featured in Nature Communications.

In this scenario, Bethany Huot, MSU cell and molecular biology graduate program alumna and the study's lead author, wanted to find out if plants' defense system was compromised or was pathogens' virulence enhanced?

The answer: It's both.

"Just like people, plants are more likely to get sick when they are growing in stressful environments," said Huot, who published the paper with Sheng Yang He, University Distinguished Professor of plant biology and a Howard Hughes Medical Institute Investigator, and Beronda Montgomery, MSU Foundation Professor. "While individual stresses are damaging to plants, they can have catastrophic effects when combined."

The researchers showed on the genetic level how high temperature weakens plant defenses while, separately, strengthening bacterial attacks.

When people get a fever, they take a form of salicylic acid, or SA, commonly known as aspirin. Plants don't have to go to a medicine cabinet because they're able to make their own SA. At 73 degrees Fahrenheit, plants can produce plenty of SA to fight off a pathogenic infection. However, when the heat rose above 86 degrees, no SA was produced, leaving plants vulnerable.

The authors also found that the pathogen became stronger at the elevated temperature. However, the increased vulnerability of the plants occurred regardless of whether the pathogen was present.

"Since the plants could no longer make SA at elevated temperature, we sprayed them with a chemical that acts like SA," Huot said. "This treatment effectively protected the plants from infection; even though the bacteria are more virulent at high temperatures, plants can fight them off if we give them the SA they can no longer make."

Even if global climate issues are resolved, local fluctuations in environment will always occur and greatly impact crop growth and yield, Huot added.

"Increasing our understanding of how specific environmental factors affect the host and the pathogen as well as their interactions can inform strategies for developing robust crop resistance," she said. "This is important for keeping food on the table."

Read the paper: Dual impact of elevated temperature on plant defence and bacterial virulence in Arabidopsis.

Article source: Michigan State University.

News

Plant mothers 'talk' to their embryos via the hormone auxin

While pregnancy in humans and seed development in plants look very different, parallels exist -- not least that the embryo develops in close connection with the mother. In animals, a whole network of signals from the mother is known to influence embryo development. In plants, it has been clear for a while that maternal signals regulate embryo development. However, the signal itself was unknown -- until now. Plant scientists at the Institute of Science and Technology Austria (IST Austria), Central European Institute of Technology (CEITEC) and the University of Freiburg have now found that a plant hormone, called auxin, from the mother is one of the signals that pattern the plant embryo. Their study is published in Nature Plants.


Archaeologists discover bread that predates agriculture by 4,000 years

At an archaeological site in northeastern Jordan, researchers have discovered the charred remains of a flatbread baked by hunter-gatherers 14,400 years ago. It is the oldest direct evidence of bread found to date, predating the advent of agriculture by at least 4,000 years. The findings suggest that bread production based on wild cereals may have encouraged hunter-gatherers to cultivate cereals, and thus contributed to the agricultural revolution in the Neolithic period.


Climate change-induced march of treelines halted by unsuitable soils

New research from the University of Guelph is dispelling a commonly held assumption about climate change and its impact on forests in Canada and abroad.