Thlaspi, eller pennycress, er et genus af urter af tempererede regioner på det eurasiske kontinent. De forekommer i Central- og Syd-Europa, Sydvestasien og 2 arter er endemiske for Kina. Thlaspi har vist sig at være en hyperaccumulator af tungmetaller som zink og cadmium og kan derfor anvendes i phytoremediation initiativer

Noccaea minima

Scientists have long observed that <a href="https://www.earth.com/news/fungi-everywhere/">fungi</a> come in an assortment of shapes and sizes. However, these differences – referred to in the scientific community as the “disparity” of a group – had never been thoroughly analyzed. Now, a research team from the <a href="https://www.bristol.ac.uk/">University of Bristol</a> has found that the vast anatomical variety of fungi stems from evolutionary bursts in multicellular complexity.



“Prior to our analyses, we didn’t know how this variety was distributed across the different types of fungi,” said study lead author Thomas Smith, who conducted the research while at Bristol’s&nbsp;<a href="http://www.bristol.ac.uk/earthsciences/">School of Earth Sciences</a>. “Which groups are the most varied when considering all parts of the fungal body plan? Which are the least? How has this variety accumulated and diminished through time? What has shaped these patterns in disparity? These are the questions we sought to answer.”



Their investigation revealed that fungal disparity has evolved episodically through time, with the evolution of multicellularity in different types of fungi opening the door for greater morphological variety. The researchers found increases in diversity linked to both the emergence of the first multicellular fungi, and later on with the evolution of complex fruiting bodies such as mushrooms or saddles in dikaryotic species, which contain cells with two separate nuclei.



According to the scientists, these results align with those of previous studies analyzing animal disparity: both animals and fungi are characterized by clumpy distributions of anatomical variety that have evolved intermittently through time. “The world of fungi is defined by bright colors, strange shapes, and stranger anatomies. Our analyses demonstrate that this breath-taking anatomical variety has evolved in bursts, driven by evolutionary increases in multicellular complexity,” Smith said.



These findings bring scientists closer to characterizing, visualizing, and analyzing the disparity of all multicellular life. In future studies, by starting with in-depth analyses of plants and algae, they aim to combine the datasets characterizing the disparity of the fungus, plant, and animal kingdoms in order to further expand and fine-tune their taxonomy.



The study is published in the journal <a href="https://www.nature.com/natecolevol/">Nature Ecology &amp; Evolution</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Fungal variety shaped by evolutionary bursts in complexity

Scientists have long observed that fungi come in an assortment...

Scientists are finding an ecological and economic balance between <a href="https://www.earth.com/news/biodiversity-loss-weakens-ecosystem-functioning/">biodiversity</a> and vanilla cultivation in Madagascar. A team of researchers led by the <a href="https://www.uni-goettingen.de/en/1.html">University of Göttingen</a> has found a way to cultivate a cash crop while preserving biodiversity in Madagascar.&nbsp;



Although the vanilla industry in Madagascar brings positive and negative outcomes to the local Malagasy, it cannot be denied that the enterprise is a significant source of income for those fortunate enough to have the land to grow vanilla and resources to protect it.



"In northeastern Madagascar, the export of vanilla is an important source of income for tens of thousands of smallholder farmers and the widespread cultivation is a way to escape from poverty," explained study first author Dr. Annemarie Wurz.



The research team found vanilla cultivated on fallow land (agricultural land left unworked for some time) was better for biodiversity than vanilla cultivated in forests. For example, the experts found that vanilla grown in the forest led to a 47 percent decrease in endemic species. This number is depressing, especially considering that Madagascar is known for its unique species.&nbsp;



The study, published in the journal <a href="http://www.nature.com/articles/s41467-022-30866-8">Nature Communications</a>, was focused on biodiversity in Madagascar's northeastern area, a region known to be the world's largest vanilla producer. Wildlife examined for the study included trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants.



The researchers discovered that growing vanilla on fallow land does not sacrifice economic gain since fallow land production and forest cultivation produce similar yields.



"The good news is that farmers do not have to clear land to achieve high yields. In fact, they can add value for biodiversity to fallow land by cultivating vanilla there," said Dr. Annemarie Wurz.



However, it should be noted that the density and length of the vanilla plants themselves could harm some aspects of biodiversity. The study found that denser and longer plants were better for crop yields but harmed tree and reptile species.



Nevertheless, the findings of this study could be crucial in conserving the biodiversity and economy of this delicate country.&nbsp;



"Promoting vanilla cultivation on fallow land is ecologically and economically significant," said study co-author Professor Ingo Grass. "This contributes to the current UN Decade for Ecosystem Restoration. In addition, this study illustrates possibilities for promoting and conserving biodiversity outside protected areas."



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By <a href="mailto:nire518@gmail.com">Erin Moody </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Vanilla cultivation can boost biodiversity in Madagascar

Scientists are finding an ecological and economic balance between biodiversity...

Charles Darwin found remarkable <a href="https://www.earth.com/news/birds-expanded-into-quieter-cities-during-covid-lockdowns/">birds</a> on the Galápagos Islands when he visited on the HMS Beagle in 1835. They became known as “Darwin’s finches,” even though they were not finches at all. The remarkable thing about them, however, was that the 18 species all seemed to inhabit different islands in the archipelago. Over time they had developed different lifestyles, fed on different foods and had beaks that varied in form and function, despite the fact that they all arose from a single ancestral species.&nbsp;



The finches illustrate that populations may become adapted to environmental conditions found on specific islands and that, over time, the adaptations may make then so different that they can be considered separate species. They also support the island syndrome hypothesis that predicts the repeated and pronounced changes that some species undergo after colonizing islands. 



Animal species that become isolated on islands often show changes in body size (may become dwarfs or giants), locomotion (may become flightless), coloration and behavior. But what is the genetic basis for these changes, and does island syndrome apply to plants as well? 



A team of 30 scientists from four different continents has now tackled these questions using plants from the genus Scalesia. Known as giant daisies, they are found on the Galápagos Islands and were also encountered there by Darwin during his visit. There are 15 different species and, as you might guess, the remarkable thing about them was that, according to Darwin, “not one of these species grows on any two islands” – each species had adapted to the conditions on its own island. Scalesia is in the same family as daisies and sunflowers but the plants grow to the size of trees on the Galápagos Islands.



All 15 species evolved from a single species that, at some point in the distant past, arrived on the archipelago. The original species spread to neighboring islands and became adapted to the specific environmental conditions there. The descendants developed different characteristics and gradually turned into more specialized species, just like the finches. In fact, the giant daisies are commonly referred to as “Darwin’s finches of the plant world”. Today the different species are adapted to life in the dry lowlands, humid highlands and dry volcanic summits of Galápagos Islands.



The researchers chose to carry out DNA analysis of a single species of giant daisy, Scalesia atractyloides, in order to investigate the genetic basis of the plant’s adaptability. This species is a critically endangered dwarf tree found only on the island of Santiago in the Galápagos. Santiago is one of the four islands that Darwin visited during his trip to the archipelago.



“We sequenced and described the genome of the plant,” said José Cerca, a researcher in NTNU’s (The Norwegian University of Science and Technology) Department of Natural History at the NTNU University Museum. Cerca worked with Michael D. Martin, a professor and genetic expert in the Department of Natural History.



The results of the analysis, published in the journal <a href="https://www.nature.com/ncomms/">Nature Communications</a>, show many genetic variants in the plant’s genome that could have explained the original species’ ability to adapt and spread into distinct niches on the different islands.



“These variations are associated with vascular development, growth, adaptation to salinity and flowering time,” said Cerca. In other words, they reflect adaptability when faced with new environmental conditions on the islands.



In total, the researchers identified 920 genes in the genome that are under positive selection, meaning that they confer some form of advantage on the plant. These include genes that regulate leaf morphology, lead to rapid plant growth, promote tolerance of arid conditions and cause the closure of stomata.&nbsp;&nbsp;



In addition, the methods used by the researchers enabled them to infer what the genome of the original colonizing plant might have looked like. “We found that the common ancestor of all the species in the&nbsp;Scalesia&nbsp;genus was an allotetraploid,” says Cerca. An allotetraploid is a variant that has twice as many chromosomes in its cells, and therefore also genes, as a normal plant. This came about because two different plants had crossbred sometime in the history of the species, and had created a hybrid.



The crossbreeding, along with the extra sets of chromosomes and genes, also provides a large variety of genetic material for different traits that can be present in the offspring. This situation means that offspring have a better chance of being able to adapt to conditions in a new environment. Such crossbreeding is probably more common in plants than believed a few years ago, but for researchers it is still a big deal.



“We’re beginning to understand the genetic basis for how this one original plant species might have evolved into several species,” said Cerca.



The researchers also found that certain genes under selection, such as large body size, supported the island syndrome hypothesis, indicating that it is possible for some species on islands to show different phenotypes from their mainland counterparts.&nbsp;



“We’ve found irrefutable evidence of the island syndrome in the genes of Darwin's giant daisies,” said Cerca.



The group's work provides valuable insights into how species are able to adapt to different environments. This is perhaps especially important at a time when the environment in numerous places on the planet is changing faster than it has for a long time.



Image Credit: Sara Santacruz



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Study reveals how Darwin’s giant daisies spread into distinct niches

Charles Darwin found remarkable birds on the Galápagos Islands when...

While scientists have known that self-pollination can jeopardize <a href="https://www.earth.com/news/fungus-renders-corn-plants-defenseless-with-surgical-precision/">plant</a> species' long-term survival, they did not understand the mechanism behind the threat or how quickly it became detrimental. To investigate, a team of researchers led by Jeremiah Busch of <a href="https://wsu.edu/">Washington State University</a> conducted a genetic study.&nbsp;



"We found that in a very short amount of time, there were major consequences on the genomes of the plants when they had to adopt selfing," said Busch.



The team compared a group of self-pollinating monkeyflower plants to a group of bumble bee-pollinated monkeyflowers. They determined that the "selfing" plants lost between 13 and 24 percent of their genetic variation, and substantial loss occurred within nine generations.&nbsp;



We already know that genetic variation is a major factor in determining how species adapt to changing environments, so this loss could seriously hinder a plant's ability to survive.&nbsp;



Busch explained that in selfing populations, particular genotypes might be selected for if they are shown to be advantageous. However, some harmful mutations may "hitchhike" as well. This "genetic hitchhiking" is less likely in bee-pollinated populations due to the mixing of genetic material.&nbsp;&nbsp;&nbsp;



"Strong inbreeding fundamentally altered the consequences of adaptation," explained Busch. The findings are especially tragic considering the global bee decline.&nbsp;



"If pollinators are lost, it's not just going to be a problem for the pollinators: plant populations will lose genetic variation in tens of generations - not thousands, but tens."&nbsp;



Busch would be interested to see long-term studies determining if and when population collapse occurs due to a lack of pollinators and loss of genetic variation.&nbsp;



"A really important next step is to see how fast highly inbred groups will have their viability decline over time – to know how quickly those populations will go extinct," said Busch. "We need to really understand what the consequences are from pollinator loss. It will matter for wild populations of plants and crops. A lot of crops depend on bees."



This study can be found in the journal <a href="https://onlinelibrary.wiley.com/doi/10.1111/evo.14572">Evolution</a>.



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By <a href="mailto:nire518@gmail.com">Erin Moody </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Bees do it better: self-pollinating plants lose genetic diversity

While scientists have known that self-pollination can jeopardize plant species'...

A team of researchers led by the <a href="https://www.uni-bonn.de/en/university">University of Bonn</a> has examined the ways in which a harmful <a href="https://www.earth.com/news/fungi-everywhere/">fungus</a> – Ustilago maydis – reproduces in the aerial parts of the corn plant and renders it defenseless. According to the experts, huge tumor-like tissue growth, known as galls, form at the site of the infection after being triggered by molecules released by the fungus - called effectors - which manipulate the plant’s metabolism and suppress its immune defenses. These effectors are also promoting cell growth and division in the corn by interfering with a plant signaling pathway regulated by the hormone auxin.



“The fungus uses this auxin signaling pathway for its own purposes,” said study senior author Armin Djamei, an expert in Plant Pathology at the University of Bonn. “This is because the huge growth of the tissue devours energy and resources that are then lacking for defense against&nbsp;Ustilago maydis. In addition, the fungus finds an ideal supply of nutrients in the growths and can multiply well there.”



“We therefore wanted to find out how the fungus promotes these proliferation processes. To do this, we searched for genetic material in the fungus that enables it to control the auxin signaling pathway of its host plant and thus its cell growth.”



The investigation revealed a cluster of five genes – called Tip1 to Tip5 – that the fungus uses to manipulate corn’s auxin signaling pathway. “The proteins encoded by the five Tip genes can bind to a protein in the corn plant known to experts as Topless,” explained lead author Janos Bindics, a researcher at the <a href="https://www.oeaw.ac.at/imba/home">IMBA Institute of Molecular Biotechnology</a> in Vienna.



Topless is a central switch that suppresses various signaling pathways in the plant. The fungal effectors produced by the cluster of Tip genes override this suppression, specifically for signaling pathways that benefit the fungus, such as the auxin one. “Figuratively speaking, the fungus acts with surgical precision. It accomplishes exactly what it needs to accomplish to best infect the corn plant,” said Dr. Djamei.



Since there are various pathogens that interfere with the auxin signaling pathways of the host plants which they infect, further research is needed to better understand the infection process in different plant diseases. By using this study’s findings, “it will be possible for the first time to influence specific effects of the auxin signaling pathway in a very targeted manner and thus to elucidate the effect of these important plant hormones even more precisely,” as Dr. Djamei put it.&nbsp;



The research is published in the journal <a href="https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.18315">New Phytologist</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp; &nbsp;

Fungus renders corn plants defenseless with surgical precision

A team of researchers led by the University of Bonn...

Growth of the Amazon rainforest in our increasingly carbon-rich atmosphere could be significantly limited by a lack of phosphorus in the soil, according to a new study led by Brazil’s <a href="https://www.gov.br/inpa/pt-br">National Institute of Amazonian Research</a> (INPA) and the <a href="https://www.exeter.ac.uk/">University of Exeter</a>.



Although higher concentrations of <a href="https://www.earth.com/news/carbon-dioxide-has-a-minimal-impact-on-tropical-vegetation/">carbon dioxide</a> cause plants to grow faster to store more of this greenhouse gas – and thus help mitigating climate change – plants also need nutrients such as nitrogen and phosphorus to grow. As a consequence, reduced availability of such nutrients could limit the Amazon rainforest’s ability to increase its productivity, or growth rate, as CO2 rises, and make it less resilient to climate change.



“Our results question the potential for current high rates of carbon uptake in Amazonia to be maintained,” said study lead author Hellen Fernanda Viana Cunha, a doctoral student in Tropical Forest Science at INPA. “About 60 percent of the Amazon basin is on old soils with low phosphorus content, but the role of phosphorus in controlling productivity was unclear because most fertilization experiments in other parts of the world have been in more phosphorus-rich systems.”



To examine the effects of adding phosphorus, nitrogen, and other key nutrients in an old-growth, low-phosphorus area of the rainforest, the researchers conducted a longitudinal empirical study - the&nbsp;<a href="https://amazonfertilisationexperiment.wordpress.com/">Amazon Fertilisation Experiment</a>&nbsp;(AFEX) – and found that only phosphorus led to increased productivity in the first two years of the experiment. “Having such rapid and strong responses to phosphorus, both above and below ground, is an indication that the whole system was functioning under severe phosphorous limitation,” Cunha explained.



While other nutrients such as nitrogen can be absorbed from the atmosphere by micro-organisms associated with certain soils and plants, phosphorus is not available as an atmospheric gas. Thus, once it becomes depleted, there are little opportunities for phosphorus levels to increase.&nbsp;



The experiments revealed that two years with extra phosphorus led to a significant increase in fine root growth (29 percent) and canopy productivity (19 percent), but not in stem growth. According to Cunha, this may be because roots and leaves require more phosphorus than stem. However, since stem growth is also a much slower process, long-term monitoring is necessary to determine whether stem wood productivity will later on increase.



This study has major implications not only for the rainforest’s carbon storage capacity, but also for its resilience to climate change. “To cope with and recover from increased threats such as droughts, we need the forest to be growing better than it used to,” said&nbsp;Iain Hartley, a professor of Geography at Exeter.



“CO2 fertilization could increase the forest’s resilience, but our findings suggest phosphorus availability will limit that effect – and therefore the risks caused by climate change become increasingly important. In short, parts of the rainforest growing in low-fertility soils may be more vulnerable than is currently recognized,” he concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1038/s41586-022-05085-2">Nature</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Lack of phosphorus will limit growth of the Amazon rainforest

Growth of the Amazon rainforest in our increasingly carbon-rich atmosphere...

Dry,Drought,Stricken,Farm,Corn,Field,Dirt

Scientists have identified an “exquisite” natural mechanism that helps plants limit their <a href="https://www.earth.com/news/transforming-sunlight-and-water-into-renewable-energy/">water</a> loss with little effect on carbon dioxide (CO2) intake. The study, led by <a href="https://www.anu.edu.au/">Australian National University</a> (ANU), touches on an essential process for photosynthesis, plant growth and crop yield.&nbsp;



The discovery is expected to help agricultural scientists and plant breeders develop more water-efficient crops that are resilient to extreme weather events such as drought.&nbsp;&nbsp;



“Plants continuously lose water through pores in the ‘skin’ of their leaves. These same pores allow CO2 to enter the leaves and are critical to their survival,” said study co-author Dr Marquez.&nbsp; “For every unit of CO2 gained, plants typically lose hundreds of units of water. This is why plants require a lot of water in order to grow and survive."



“The mechanism we have demonstrated is activated when the environment is dry, such as on a hot summer day, to allow the plant to reduce water loss with little effect on CO2 uptake."



The researchers believe this water preserving mechanism can be manipulated to breed more water-efficient crops.&nbsp;&nbsp;



According to study lead author Dr. Chin&nbsp; Wong, the ANU team’s findings are a “dream discovery” from a scientific and agricultural perspective. The agricultural industry has long waited for a way to deliver crops that use water efficiently.&nbsp;



Although the researchers have confirmed there is a system in place that is working to limit the amount of water being lost from the leaf, they still do not know what’s causing it.&nbsp;&nbsp;&nbsp;



“Our main target now is to identify the structures inside the plant that allow this control. We think that water conduits, called aquaporins, located in the cell membranes are responsible,” said Dr. Marquez.&nbsp;



Once this can be confirmed, the team will continue to explore how these systems can become an asset for the agriculture industry.



Dr. Wong first alluded to this water preserving mechanism 14 years ago, but the research team has only now been able to officially confirm its existence thanks to years of experimentation and corroboration of their results.&nbsp;&nbsp;



The study is published in the journal <a href="https://www.nature.com/nplants/">Nature Plants</a>.&nbsp;



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By <a href="mailto:katherinebucko@gmail.com">Katherine Bucko</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

"Exquisite" mechanism will help plants survive drought

Scientists have identified an “exquisite” natural mechanism that helps plants...

Noccaea minima

Description

Taxonomic tree: