Despite decades of intense research, little is known of the plant molecules that allow fungal hyphae to invade the host’s epidermal cells.
A European research group lead by Ueli Grossniklaus, a plant geneticist at the University of Zurich, now published a study in Science shedding a new light on mildew susceptibility in plants and its surprising link to reproduction.
Investigating mildew susceptibility in plants is not really a main research focus for Ueli Grossniklaus, a professor for plant genetics at the University of Zurich, Switzerland. Grossniklaus’ lab mainly investigates the molecular mechanism of both sexual and asexual plant reproduction. His group conducts fundamental research on the model plant Arabidopsis thaliana, whose complete genome has been deciphered.
Recently, Grossniklaus and his team uncovered a mutant that they named nortia after an Etruscan goddess of fertility. Together with FERONIA – a gene Grossniklaus’ group had previously discovered – NORTIA plays a key role in the communication between the female and male cells during fertilization. Surprisingly, examination of the structure of the NORTIA gene revealed that it was very similar to the structure the Mlo gene of barley. In barley, Mlo is responsible for powdery mildew susceptibility, with mlo mutants showing a resistance against many strains of powdery mildew infection. This mutation is the only known permanent resistance against powdery mildew infection and it is widely used in barley breeding. Plants with such inherent resistance are of great importance, as they reduce crop loss due to powdery mildew infection without the use of fungicides. Up until now, little was known about the molecular components that allow the fungus to penetrate the epidermal cells of leafs of other plants.
Pollination and fungal infections are based on similar communication mechanisms
In flowering plants, fertilization occurs after the male pollen tube penetrates the female sexual apparatus, a process controlled by NORTIA and FERONIA. Until the mid 19th century, pollen tubes were considered fungus-like pathogens, before their role in fertilization was discovered. This is because, similar to pollen tubes, pathogenic fungal hyphae penetrate the plant’s tissue via tip growth. So the scientists further investigated the connection between the tip growing pollen tubes and tip growing fungus hyphae.
”NORTIA is only expressed in sexual apparatus of the plant. So there is no way for NORTIA to be responsible for powdery mildew susceptibility,” Grossniklaus explained. Therefore, the researchers focused on the role of feronia, the second mutant important for pollen tube reception. Contrary to NORTIA, FERONIA is expressed in throughout the plant, including the leaf epidermis. In collaboration Ralph Panstruga’s group at the Max Planck Institute for Plant Breeding Research in Cologne, Germany, the scientists could demonstrate that Arabidopsis with the wild-type FERONIA gene was susceptible to powdery mildew infection. Plants with an inactivated feronia gene, however, were resistant against powdery mildew. But the plant pays an enormous price for such resistance: the plant is infertile. Both identification processes – of either tip growing pollen tubes or invading fungal hyphae – seem to use the same or very similar molecules. As Grossniklaus stresses: ”This explains why plants could not get rid of the gene causing powdery mildew susceptibility during the course of evolution.”
Among researchers working on powdery mildew, these results have caused enormous interest worldwide as the signal pathway of powdery mildew infection is still poorly understood. Facing a constantly growing population, it is important to be able to breed crops beside barley with a permanent resistance against powdery mildew. The close linkage of powdery mildew susceptibility and fertility show how difficult it will be to achieve this goal.
Literature: Sharon A. Kessler, Hiroko Shimosato-Asano, Nana Friderike Keinath, Samuel Elias Wuest, Gwyneth Ingram, Ralph Panstruga and Ueli Grossniklaus, Conserved molecular components for pollen tube reception and fungal invasion, in: Science, 12. November 2010, Vol. 330. no. 6006, pp. 968 – 971, DOI: 10.1126/science.1195211Contact:
Beat Müller | idw
Alkaline soil, sensible sensor
03.08.2017 | American Society of Agronomy
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences