DELLAs bolster symbiosis in Green Revolution crops

Jan 08, 2014 by Amanda Gurung
DELLAs bolster symbiosis in Green Revolution crops
Arbuscules, portrayed in green, inside the roots of the Medicago truncatula legume plant, shown in red. Credit: BTI/Harrison Lab

(Phys.org) —Boyce Thompson Institute and Cornell researchers have identified a plant protein called DELLA that may lead to reducing phosphorus-fertilizer applications on farms and better plant growth in poor soil.

Plant biologists have long known that through "mycorrhizal symbiosis" – an interface between the and the soil – regulate formation of arbuscules (branched, treelike structures) in response to their own phosphate needs. The mycorrhizal fungus transfers phosphate from the soil into plant cells through the arbuscules and – in exchange – the plant feeds the fungus with sugars.

The researchers analyzed a legume plant (Medicago truncatula) to show that DELLA proteins are essential for arbuscule formation.

When a plant is phosphate-starved, DELLA protein levels are high, and this restrains plant growth. But in mycorrhizal associations, this protein promotes arbuscule formation. "Once arbuscules have formed, phosphate is delivered to the plant and the increases," said corresponding author Maria Harrison, the William H. Crocker Scientist at Boyce Thompson Institute and a Cornell adjunct professor.

Phosphorus fertilizers can be costly to farmers, and without the help of beneficial , much of a fertilizer's nutrients can be out of reach of the plant roots, unabsorbed in the soil and washed into waterways, to the detriment of nearby ecosystems.

Green Revolution crops contain dominant DELLA protein mutants, which show more arbuscules and fungus in the roots, say the researchers. Consequently, the breeding for high yielding dwarfs – the Green Revolution-style breeding – had unanticipated consequences on the mycorrhizal symbiosis. The researchers' experiments imply that growing these crops will have increased the amounts of mycorrhizal fungi in the soil and will influence soil health in a positive way.

Explore further: How scavenging fungi became a plant's best friend

More information: Daniela S. Floss, Julien G. Levy, Véronique Lévesque-Tremblay, Nathan Pumplin, and Maria J. Harrison. "DELLA proteins regulate arbuscule formation in arbuscular mycorrhizal symbiosis." PNAS 2013 ; published ahead of print December 2, 2013, DOI: 10.1073/pnas.1308973110

Related Stories

How scavenging fungi became a plant's best friend

Nov 25, 2013

Glomeromycota is an ancient lineage of fungi that has a symbiotic relationship with roots that goes back nearly 420 million years to the earliest plants. More than two thirds of the world's plants depend ...

Fungi reduce need for fertilizer in agriculture

May 23, 2011

The next agricultural revolution may be sparked by fungi, helping to greatly increase food-production for the growing needs of the planet without the need for massive amounts of fertilizers according to research presented ...

With fungi on their side, rice plants grow to be big

Jun 10, 2010

By tinkering with a type of fungus that lives in association with plant roots, researchers have found a way to increase the growth of rice by an impressive margin. The so-called mycorrhizal fungi are found ...

Recommended for you

Building better soybeans for a hot, dry, hungry world

49 minutes ago

(Phys.org) —A new study shows that soybean plants can be redesigned to increase crop yields while requiring less water and helping to offset greenhouse gas warming. The study is the first to demonstrate ...

Gene removal could have implications beyond plant science

1 hour ago

(Phys.org) —For thousands of years humans have been tinkering with plant genetics, even when they didn't realize that is what they were doing, in an effort to make stronger, healthier crops that endured climates better, ...

Chrono, the last piece of the circadian clock puzzle?

15 hours ago

All organisms, from mammals to fungi, have daily cycles controlled by a tightly regulated internal clock, called the circadian clock. The whole-body circadian clock, influenced by the exposure to light, dictates the wake-sleep ...

Drought hormones measured

15 hours ago

Floods and droughts are increasingly in the news, and climate experts say their frequency will only go up in the future. As such, it is crucial for scientists to learn more about how these extreme events affect plants in ...

User comments : 0

More news stories

Ranchers benefit from long-term grazing data

Scientists studying changes in the Earth's surface rely on 40 years of Landsat satellite imaging, but South Dakota ranchers making decisions about grazing their livestock can benefit from 70 years of data ...

Melting during cooling period

(Phys.org) —A University of Maine research team says stratification of the North Atlantic Ocean contributed to summer warming and glacial melting in Scotland during the period recognized for abrupt cooling ...