PHS gene prevents wheat from sprouting: Fewer crop losses anticipated

Preharvest sprouting can cause significant losses in wheat crops, particularly in white wheat crops. Credit: Kansas State University Photo Services

A new study about the common problem of preharvest sprouting, or PHS, in wheat is nipping the crop-killing issue in the bud.

Researchers at Kansas State University and the U.S. Department of Agriculture-Agricultural Research Service, or USDA-ARS, found and cloned a gene in wheat named PHS that prevents the plant from preharvest sprouting. Preharvest sprouting happens when significant rain causes the wheat grain to germinate before harvest and results in significant crop losses.

"This is great news because preharvest sprouting is a very difficult trait for wheat breeders to handle through breeding alone," said Bikram Gill, university distinguished professor of plant pathology and director of the Wheat Genetics Resource Center. "With this study, they will have a gene marker to expedite the breeding of wheat that will not have this problem."

Gill conducted the study with Guihau Bai, a researcher with the Hard Winter Wheat Genetics Research Unit of the USDA-ARS, adjunct professor of agronomy at Kansas State University and the study's lead author. Also involved were Harold Trick, professor of plant pathology; Shubing Liu, research associate in agronomy; Sunish Sehgal, senior scientist in plant pathology; Jiarui Li, research assistant professor; and Meng Lin, doctoral student in agronomy, all from Kansas State University; and Jianming Yu, Iowa State University.

Their study, "Cloning and Characterization of a Critical Regulator for Pre-Harvest Sprouting in Wheat," appears in a recent issue of the scientific journal Genetics.

The finding will to be most beneficial to white wheat production, which loses $1 billion annually to preharvest sprouting, according to Gill.

He said consumers prefer white wheat to the predominant red wheat because white wheat lacks the more bitter flavor associated with red wheat. Millers also prefer white wheat to red because it produces more flour when ground. The problem is that white wheat is very susceptible to preharvest sprouting.

"There has been demand for white wheat in Kansas for more than 30 years," Gill said. "The very first year white wheat was grown in the state, though, there was rain in June and then there was preharvest sprouting and a significant loss. The white wheat industry has not recovered since and has been hesitant to try again. I think that this gene is a big step toward establishing a white wheat industry in Kansas."

Gill said identifying the PHS gene creates a greater assurance before planting a crop that it will be resistant to preharvest sprouting once it grows a year later. Wheat breeders can now bring a small tissue sample of a wheat plant into a lab and test whether it has the preharvest sprouting resistance gene rather than finding out once the crop grows.

Much of the work to isolate the PHS gene came from Gill and his colleagues' efforts to fully sequence the genome -- think genetic blueprint -- of common wheat. Wheat is the only major food plant not to have its genome sequenced. The genome of wheat is nearly three times the size of the human genome.

Researchers were able to study sequenced segments of the common wheat genome and look for a naturally occurring resistance gene. Gill said without the sequenced segments, finding the PHS gene would have been impossible.

Source: Kansas State University

Kilauea, 1790 and today

The Island of Hawai'i, USA.

Scores of people were killed by an explosive eruption of Kīlauea Volcano, Hawai'i, in 1790. Research presented in GSA Bulletin by D.A. Swanson of the Hawaiian Volcano Observatory and colleagues suggests that most of the fatalities were caused by hot, rapidly moving surges of volcanic debris and steam that engulfed the victims. Deposits of such surges occur on the surface on the west summit area and cover an ash bed indented with human footprints.

The footprints, made by warriors and their families, appear along a major trail in use at the time. Today, the area is one of the most visited parts of Hawai'i Volcanoes National Park.
The explosive eruption resulted from the violent interaction of groundwater with hot rocks. Such explosive eruptions have happened frequently in Kīlauea's past and will probably occur in the future when the caldera collapses down to the water table, some 600 m (2000 ft) below the summit of the volcano.

The 1790 eruption of Kīlauea was explosive, and its major impacts were in the summit area of the volcano. The eruption taking place now at Kīlauea is effusive, says Swanson, producing a flow of lava that erupts without explosion. This flow is erupting from a site named Pu'u 'Ō'ō on the east rift zone, far from the summit area, and lava has to flow many kilometers (several miles) before reaching inhabited areas.

Explosive eruptions are very hazardous; the 1790 fatalities bear witness to this fact. Lava flows are not very hazardous to life but can be exceedingly destructive to property. Explosive eruptions are brief but terrifying. Lava flows often last for months or more and are captivating to the viewer. Kīlauea has both types of eruptions, but not at the same time.

Violent explosive eruptions from the summit of Kīlauea are geologically common. They are generally clustered into periods lasting a few centuries. It has been about 200 years since the most recent major explosion, which culminated about 300 years of frequent explosive eruptions. In the past 200 years, Kīlauea has produced many lava flows similar to the present one; small explosions took place in 1924 and, on an even smaller scale, during the past 6 years.

The general public is unaware of Kīlauea's explosive nature, because the volcano has erupted mainly lava flows in recent times. Kīlauea will almost certainly become explosive at some future time, producing conditions similar to those of 1790. However, according to Swanson, there is no reason to think that a period of violent eruptions will resume any time soon. The public can probably expect more lava flows in the near future, such as those of the past three decades from Pu'u 'Ō'ō.

Source: Geological Society of America

New species of beetle discovered in the world's deepest cave

This is a drawing of Duvalius abyssimus. Credit: Sinc - José Antonio Peñas

The unusual habitat of the Krubera cave in the Western Caucasus remains a mystery. Researchers from two Spanish universities have discovered a new species of beetle in the depths of this cave.

Cave beetles are one of the most iconic species found in subterranean habitats. They were historically the first living organisms described by science that are adapted to the conditions of hypogean or subterranean life.

Now, a Portuguese scientist and a Spaniard have discovered a new species of beetle in the deepest cave known to man; a cave 2,140 metres deep. It is the Krubera cave, situated in the Arabika massif in the Western Caucasus.

Ana Sofía Reboleira, researcher from the Universities of Aveiro and La Laguna, and Vicente M. Ortuño, from the University of Alcalá, have published their discovery in the scientific journal 'Zootaxa'.

"The new species of cave beetle is called Duvalius abyssimus. We only have two specimens, a male and a female. Although they were captured in the world's deepest cave, they were not found at the deepest point," Ortuño, who has dedicated the last 10 years to studying subterranean fauna, said.

The Duvalius genus is a successful colonizer of Earth's depths. The majority of species have a hypogean lifestyle and live in caves or the superficial underground compartment.

"The new species' characteristics indicate that it is moderately adapted to life underground. Proof of this is that they still have eyes, which are absent in the highly specialised cave species," added the expert.

The Arabika massif region in Abkhazia, where this cave is found, is biogeographically a very interesting area. Altitudes fluctuate between 1,900 and 2,500 metres and the cave is composed of lower and upper Jurassic-Cretaceous limestone.

Its large area has provided endless subterranean refuges for fauna. In fact, various genera of endemic cave beetles live in the Western Caucasus. "Its location is strategic, since there are fauna of European, Asian and also endemic origin in the zone," the scientist underlined.

The entrance to the cave is 2,240 metres above sea level and 15 kilometres from the Black Sea. Below numerous vertically-cutting sections, it reaches a depth of 1,400 metres. From this level, it splits into branches and in order to reach the greatest known depth, it is necessary to pass various flooded underground chambers using diving techniques.

"The discovery of the new beetle provides important data on species that co-exist in these almost unknown ecosystems, even more so when they are found in a geographical area that is very difficult to access, such is the case with this cave," Ortuño concluded.

Source:  FECYT - Spanish Foundation for Science and Technology

Brazilian zoologists discovered the first obligate cave-dwelling flatworm in South America

The type locality of the new cave-dwelling species in northeastern Brazil is shown.
 Credit: Rodrigo Ferreira; CC-BY 4.0

Typical cave-dwelling organisms, unpigmented and eyeless, were discovered in a karst area located in northeastern Brazil. The organisms were assigned to a new genus and species of freshwater flatworm and may constitute an oceanic relict. They represent the first obligate cave-dwelling flatworm in South America. The study was published in the open access journal ZooKeys.

Freshwater flatworms occur on a wide range of habitats, namely streams, lagoons, ponds, among others. Some species also occur in subterranean freshwater environments.

Brazil has more than 11,000 caves, but their species diversity is largely unknown. Field work by Rodrigo Ferreira, from University of Lavras, Brazil, in a karst area located in northeastern Brazil, has found the first obligate cave-dwelling flatworm in South America. Flatworm researchers from University of Vale do Rio dos Sinos (UNISINOS), Brazil, Ana Leal-Zanchet and Stella Souza, described it as a new genus and species.

The new species, which was named Hausera hauseri, is a typical cave-dwelling organism, unpigmented and eyeless. The genus and species names were proposed in honour to a Hungarian biologist, the late Prof. Dr. Josef Hauser, who immigrated to Brazil and studied freshwater flatworms over many years.

The sampling area of the new species is unique in comparison with other karst areas in Brazil. Most Brazilian limestone formations are located in inner portions of the country, which must have prevented marine groups from colonizing these caves in the past. In contrast, this karst area is located near the sea, and its limestone outcrops are at low altitude, which has allowed different invertebrates to colonize the caves during sea level rises in the past. Thus, the new species may constitute an oceanic relict as is the case of other cave-dwelling invertebrates found in this karst area in northeastern Brazil.

Source: Pensoft Publishers

A kingdom of cave beetles found in Southern China

Credit: Mingyi Tian; CC-BY 4.0

A team of scientists specializing in cave biodiversity from the South China Agricultural University (Guangzhou) unearthed a treasure trove of rare blind cave beetles. The description of seven new species of underground Trechinae beetles, published in the open access journal ZooKeys, attests for the Du'an karst as the most diverse area for these cave dwellers in China.

"China is becoming more and more fascinating for those who study cave biodiversity, because it holds some of the most morphologically adapted cavernicolous animals in the world. This is specifically true for fishes and the threchine beetles, the second of which is also the group featured in this study," explains the senior author of the study Prof. Mingyi Tian.

Like most cavernicolous species, Trechinae cave beetles shows a number of specific adaptations, such as lack of eyes and colour, which are traits common among cave dwellers.

The new Trechinae beetles belong to the genus Dongodytes whose members are easily recognizable by their extraordinary slender and very elongated body. Members of this genus are usually very rare in caves, with only five species reported from China before now.

During the recent study of the cave systems in Du'an karst however this numbers drastically changed, Out of the 48 visited caves 12 held populations of trechine beetles. A total of 103 samples were collected, out of which the team of scientists determined ten different species, seven of which are new to science.

"This new discovery casts a new light on the importance of the Du'an Karst as a biological hotspot for cavernicolous Trechinae in China," adds Prof. Mingyi Tian.

Source: Pensoft Publishers

'Non-echolocating' fruit bats actually do echolocate, with wing clicks

In a discovery that overturns conventional wisdom about bats, researchers reporting in the Cell Press journal Current Biology on Dec. 4 have found that Old World fruit bats -- long classified as "non-echolocating" -- actually do use a rudimentary form of echolocation. Perhaps most surprisingly, the clicks they emit to produce the echoes that guide them through the darkness aren't vocalizations at all. They are instead produced by the bats' wings, although scientists don't yet know exactly how the bats do it.

In a discovery that overturns conventional wisdom about bats, researchers reporting in the Cell Press journal Current Biology on December 4 have found that Old World fruit bats--long classified as "non-echolocating"--actually do use a rudimentary form of echolocation. Perhaps most surprisingly, the clicks they emit to produce the echoes that guide them through the darkness aren't vocalizations at all. They are instead produced by the bats' wings, although scientists don't yet know exactly how the bats do it.

"I was surprised by the fact that all of the fruit bats we recorded clicked and by the fact that clicks are produced by the wings," says Yossi Yovel of Tel Aviv University in Israel. "Arjan and I still find that hard to believe."

Yovel and postdoctoral fellow Arjan Boonman got their first hint about the fruit bats from a friendly man on a bus in Indonesia who told them about a species of bat that clicked with its wings. As further confirmation, Boonman found a single old paper about a fruit bat with wings that clicked, but it wasn't clear whether those clicks were good for anything.

Rather than look for that one earlier-described species in particular, Yovel suggested something else: "Why not check other fruit bats?"

They selected a total of 19 wild individuals representing three species of fruit bat and different parts of the evolutionary family tree to find that all of them did produce audible clicks with their wings.

"We did all we could to prove it wrong, including sealing the bats' mouths and anesthetizing their tongues, but nothing stopped them from clicking, except for when we interfered with their wing flaps," Yovel says.

Further study showed that two of the three species increased their clicking rate by a factor of three to five or even more when placed in a dark tunnel, implying that the clicks are a natural behavior for the bats.

Tests of the animals' ability to find their way in the dark showed that the fruit bats do have echolocation abilities, although they are poorer than those of other echolocating species. The fruit bats constantly crashed into thick cables, but they could readily learn to discriminate between larger objects: an acoustically reflective black board versus a similar-looking sheet of cloth. Even with large objects, however, the fruit bats didn't exactly come in for a smooth landing, suggesting that their ability is rather rudimentary in comparison to that of bats that rely on clicks produced from their larynxes.

The findings are interesting in light of earlier suggestions that echolocation may have evolved initially for bats to identify and avoid crashing into large objects such as cave walls, Boonman and Yovel say. The new discovery in fruit bats offers insight into how this sophisticated ability in other bats may have evolved over time, although it is unlikely that the laryngeal clicks of those other bats evolved directly from fruit bats' wing clicks. In fact, Yovel says, it's possible that echolocation in bats has independently evolved many times.

"When we study extant species of echolocating bats, we see a developed sensory system that has been adapted and improved over millions of years of evolution," Yovel says. "The rudimentary echolocation of the fruit bat is one example of how the first types of echolocation may have evolved."

Source: Cell Press

The New insight may help predict volcanic eruption behavior

Using friction experiments University of Liverpool scientists have shown that frictional melting plays a role in determining how a volcano will erupt. Credit: Dr. Jackie Kendrick

A new discovery in the study of how lava dome volcanoes erupt may help in the development of methods to predict how a volcanic eruption will behave, say scientists at the University of Liverpool.

Volcanologists at the University have discovered that a process called frictional melting plays a role in determining how a volcano will erupt, by dictating how fast magma can ascend to the surface, and how much resistance it faces en-route.

The process occurs in lava dome volcanoes when magma and rocks melt as they rub against each other due to intense heat. This creates a stop start movement in the magma as it makes its way towards Earth's surface. The magma sticks to the rock and stops moving until enough pressure builds up, prompting it to shift forward again (a process called stick-slip).

Volcanologist, Dr Jackie Kendrick, who lead the research said: "Seismologists have long known that frictional melting takes place when large tectonic earthquakes occur. It is also thought that the stick-slip process that frictional melting generates is concurrent to 'seismic drumbeats' which are the regular, rhythmic small earthquakes which have been recently found to accompany large volcanic eruptions.
"Using friction experiments we have shown that the extent of frictional melting depends on the composition of the rock and magma, which determines how fast or slow the magma travels to the surface during the eruption."

Analysis of lava collected from Mount St. Helens, USA and the Soufrière Hills volcano in Montserrat by volcanology researchers from the University's School of Environmental Sciences revealed remnants of pseudotachylyte, a cooled frictional melt. Evidence showed that the process took place in the conduit, the channel which lava passes through on its way to erupt.

Dr Kendrick, from the University's School of Environmental Sciences, added: "The closer we get to understanding the way magma behaves, the closer we will get to the ultimate goal: predicting volcanic activity when unrest begins. Whilst we can reasonably predict when a volcanic eruption is about to happen, this new knowledge will help us to predict how the eruption will behave.

"With a rapidly growing population inhabiting the flanks of active volcanoes, understanding the behaviour of lava domes becomes an increasing challenge for volcanologists."

Source: University of Liverpool

The Earthquakes caused by clogged magma a warning sign of volcanic eruption

Researchers studied Augustine Volcano in Alaska which erupted in 2006 and found that precursory earthquakes were caused by a block in the lava flow. Credit: Alaska Volcano Observatory and photographer Cyrus Read.

New research in Geophysical Research Letters examines earthquake swarms caused by mounting volcanic pressure which may signal an imminent eruption. The research team studied Augustine Volcano in Alaska which erupted in 2006 and found that precursory earthquakes were caused by a block in the lava flow.

36 hours before the first magmatic explosions, a swarm of 54 earthquakes was detected across the 13-station seismic network on Augustine Island. By analyzing the resulting seismic waves, the authors found that the earthquakes were being triggered from sources within the volcano's magma conduit.
"Our article talks about a special type of volcanic earthquake that we think is caused by lava breaking, something that usually can't happen because lava is supposed to flow more like a liquid, rather than crack like a piece of rock," said Dr. Helena Buurman from the University of Alaska Fairbanks. "Much like breaking a piece of chewing gum by stretching it really fast, lab tests show that hot lava can break when stretched quickly enough under certain pressures like those that you might find in the conduit of a volcano. "

The authors found that over the course of the two hour swarm, the earthquakes' focus moved 35 meters deeper down into the magma conduit, an indication that the conduit was becoming clogged. The resulting buildup of pressure may have contributed to the explosive eruption the next day.

"We think that these earthquakes happened within the lava that was just beginning to erupt at the top of Augustine. The earthquakes show that the lava flow was grinding to a halt and plugging up the system. This caused pressure to build up from below, and resulted in a series of large explosions 36 hours later," concluded Dr. Buurman. "We believe that these types of earthquakes can be used to signal that a volcano is becoming pressurized and getting ready to explode, giving scientists time to alert the public of an imminent eruption. "

Summary:
New research examined earthquake swarms caused by mounting volcanic pressure which may signal an imminent eruption. The research team studied Augustine Volcano in Alaska which erupted in 2006 and found that precursory earthquakes were caused by a block in the lava flow. 36 hours before the first magmatic explosions, a swarm of 54 earthquakes was detected across the 13-station seismic network on Augustine Island. By analyzing the resulting seismic waves, the authors found that the earthquakes were being triggered from sources within the volcano’s magma conduit.

Source: Wiley