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

Plants love microbes -- and so do farmers

The Australian Sunshine Coast's plant diversity has helped University of Queensland researchers confirm that nurture has the upper hand - at least when it comes to plant microbes.

Australian Centre for Ecogenomics director Professor Phil Hugenholtz said a study of microbial communities necessary for plant development, led by UQ's Yun Kit Yeoh, could improve crop and plant yields.

"Plants have evolved over 400 million years to provide favourable environments for microbes, which they host all over their bodies, from leaves to roots," said Professor Hugenholtz, of UQ's School of Chemistry and Molecular Biosciences.

Previous studies looking at the influence of microbial communities on their plant hosts had focused on model plants and crops, such as legumes and sugarcane, but not across a range of species.

At a symposium in Greece in 2012 I noticed almost all the plant researchers worked on one or, at most, a few plant species, so you'd hear them referring to each other as, he's a lettuce guy, or she's a sugarcane person," he said.

"My group is interested in the relative effects of nature versus nurture on host-associated microbiomes, and you need a good evolutionary cross-section of the host group to see whether microbiota are evolving with their hosts (nature) or are the result of environmental conditions (nurture).

"That kind of analysis was unlikely to happen if researchers weren't looking across a wide spectrum of plant species.

He said School of Agriculture and Food Sciences researcher Professor Susanne Schmidt had suggested that data from the Cooloola dunes from the Great Sandy National Park on Australia's Sunshine Coast would be ideal to answer this question.

"This comprises a wide range of plant species in close proximity in very different soil environments, allowing the nature versus nurture question to be teased apart.

"It's also important to note that Australia is one of the few places where you have access to representatives of the entire plant kingdom - you couldn't have covered the same evolutionary range of plant species in Europe for instance."

Professor Schmidt said Cooloola was ideally suited with a progressive series of dune systems that had developed over several hundred thousand years within close proximity.

"We collected root and soil samples from non-seed and seed plant lineages - lycopods, ferns, cycads, conifers and flowering plants - that co-occur across dune systems, and surveyed the resident bacterial communities," she said.

The study found that plant genetics influenced the recruitment of root communities in a manner consistent with their evolution, but this was secondary to the much larger environmental influence.

It also supported the inference that a core root microbiome has evolved with terrestrial plants over their 400 million year history.

Professor Schmidt said one significant difference between plants and animals was plants' limited ability to vertically transmit microorganisms between generations.

"Plants also have limited mobility and generally remain at a single place their entire lives. As a consequence, microbial communities associated with plants have to be primarily drawn from the environment," she said.

Similar to recent revelations on the importance of gut microbial communities in animals, there was good evidence that plant growth and vigour depended on favourable microbes.

"Increasingly, farmers want to capitalise on beneficial microbes to support their crops, and science can assist the design of effective crop probiotics to make crops healthier, hardier and more productive, by increasing their resilience to pests, diseases and environmental stresses, and improving access to nutrients," she said.

"Knowing that all plants harbour a core root microbiome is a step towards understanding the principles of the intricate relationship between microorganisms and plants.

"We now need to find out what roles these root-enriched microorganisms play and how we can harness their potential for ecological agriculture."

Read the paper: Evolutionary conservation of a core root microbiome across plant phyla along a tropical soil chronosequence.

Article source: University of Queensland.

Image credit: Lui Weber


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.