March 14, 2007, 10:15 PM CT

How Plants Manage Calcium

A new understanding of how plants manage their internal calcium levels could lead to modifying plants to avoid damage from acid rain. The pollutant disrupts calcium balance in plants by leaching significant amounts of the mineral from leaves as well as the agricultural and forest soils the plants live in.

"Our findings should help researchers understand how plant ecosystems respond to soil calcium depletion and to design appropriate strategies to protect the environment," said Zhen-Ming Pei, a Duke University biologist who led the study, which is reported in the March 9, issue of the journal Science".

The research was supported by the National Science Foundation (NSF), the U.S. Department of Agriculture and Xiamen University in China.

To grow, a plant needs a reliable supply of calcium, which enters the plant dissolved in water the roots take in from surrounding soil. As the water circulates through a plant, dissolved calcium gets shuttled where it is needed to give the plant's cells their structural rigidity. But calcium supplies coming into the plant cycle up and down over the course of the day, dropping to a minimum at night.

"Calcium is a key regulator of vital physiological functions in both plants and animals," said Maryanna Henkart, director of NSF's Division of Molecular and Cellular Biosciences. "The discovery of the relationship between calcium in soil, in plant cells, and cellular mechanisms sheds new light on the role of this important mineral in plant growth and development"......... Posted by: Erica      Read more         Source

March 12, 2007, 9:11 PM CT

Disease opened door to invading species

Plant and animal diseases can play a major and poorly appreciated role in allowing the invasion of exotic species, which in turn often threatens biodiversity, ecological function and the world economy, scientists say in a new report.

In particular, a plant pathogen appears to have opened the gate for the successful invasion of non-native grasses into much of California, one of the world's largest documented cases of invading species and one that dramatically changed the history and ecology of a vast grassland ecosystem.

The study, published recently in Proceedings of the National Academy of Sciences, a professional journal, should improve the understanding of invasive species and possibly suggest new tools to combat them, said scientists at Oregon State University.

"Even if we can't control all the diseases that help species invade, at least now we know to consider diseases when studying invasion," said Elizabeth Borer, an assistant professor of zoology at OSU. "In analyzing the ecology of exotic plant or animal species, it's clear that diseases are one part of the equation".

About 50,000 exotic species have been introduced into the United States, and the havoc they wreak upon agricultural crops, wildlife, ranch animals, forests and grasslands costs about $137 billion a year, researchers say. Invading species are also responsible for about half of all native species that go extinct, studies show......... Posted by: Erica      Read more         Source

Sat, 10 Mar 2007 14:21:56 GMT

Fritillaria imperialis 'Rubra'

In a typical year, the highlight of yesterday's discussions among staff members would have been news of the first magnolia blossom of the year. That always happy-event was overshadowed by a different topic: the theft of a crown imperial, Fritillaria imperialis. From what I've been able to determine, it was the last remaining individual of this species in the garden. It is even more discouraging to note that this theft will likely have killed the plant, as it was only a few weeks from flowering (one of the worst times to attempt a transplant; in general, fritillarias do not like to be moved at the best of times).

It is always very upsetting when plants are stolen from the garden, and, unfortunately, it happens several times a year. This is the second plant theft so far in 2007. Someone earlier in the year decided to help themselves to a small apple tree that Tony Maniezzo was growing with the intent of being a replacement for one of the espaliers – in fact, I believe it was planted right beside the pole in this photograph.

There are three things that really disgust me about these thefts: the privatization of a public shared good, the potential impact on research projects in the garden and the loss of public investment. You'll have to excuse my language as I'm not fluent in the words to best express some of these concepts, but I'll explain as best I can.

By the privatization of a public shared good, I mean the act of taking something that conceptually belongs to everyone to experience, to enjoy and to learn from and transforming it into a personal possession for the satisfaction of one person alone. I am reminded of the same sort of selfish disregard for others when reading stories about the theft of rocks in the Racetrack Playa in Death Valley. I am not sure what goes on in the mind of the thieves. Is it "I deserve this."? "They won't miss it."? "I can take better care of it."? "If I don't take it, someone else will."?

One small consolation is that this plant was not being used in any research projects. As I am sure you can imagine, thefts from research collections can potentially set back years of study. You might argue that if a plant was so important to a research project it wouldn't be left out in the open or multiple plantings would exist, but that's not the reality of gardening – a particular species might be extremely difficult to propagate, might be difficult to source, might be extremely fussy in where it grows and the required conditions can't be replicated elsewhere, and on and on. I would hate for a graduate student's thesis to have to be redone because of a plant theft.

The garden has also recently started the process of determining the investment required to grow and maintain a plant in its collection. Considering this crown imperial had been in the garden for ten years, I could provide a rough figure on how much the garden has invested, and that number would likely be surprisingly high to you. If you were trying to determine the investment, you'd have to keep in mind that the garden invests money and time into acquiring the material, growing it to a suitable size before it is ready for the garden, tracking the information on what it is and where it is located in the garden, creating tracking labels and display labels, maintaining the bed and nearby pathways for access, mulching, weeding, ensuring the accuracy of recordkeeping and so on. Its loss is not trivial.

Today's photographs are not of the plant that was stolen, but rather a horticultural selection of the same species, the cultivar 'Rubra'. These images were taken by a former employee of the garden, Justin Moore, in 2002. These plants were in the same bed as the stolen Fritillaria imperialis, but died out a couple years ago (related species and cultivars will sometimes be grown together for the ease of comparison). Some of what I described regarding theft similarly applies to plants that die (particularly investment costs). The difference? Plant death is far easier to accept as it is inevitable.

Scott Appell has written about this group of plants for Brooklyn Botanic Garden in his article, “Fritillarias – Spring Blooming Bulbs of Legends and Lore”, if you'd like to learn more.

Posted by: Daniel Mosquin      Read more     Source

March 6, 2007, 4:52 AM CT

New View On Biology Of Flavonoids

Flavonoids, a group of compounds found in fruits and vegetables that had been thought to be nutritionally important for their antioxidant activity, actually have little or no value in that role, according to an analysis by scientists in the Linus Pauling Institute at Oregon State University.

However, these same compounds may indeed benefit human health, but for reasons that are quite different the body sees them as foreign compounds, researchers say, and through different mechanisms, they could play a role in preventing cancer or heart disease.

Based on this new view of how flavonoids work, a relatively modest intake of them the amount you might find in a healthy diet with five to nine servings of fruits and vegetables is sufficient. Large doses taken via dietary supplements might do no additional good; an apple a day may still be the best bet.

A research survey, and updated analysis of how flavonoids work and function in the human body, were recently published in Free Radical Biology and Medicine, a professional journal.

"What we now know is that flavonoids are highly metabolized, which alters their chemical structure and diminishes their ability to function as an antioxidant," said Balz Frei, professor and director of the Linus Pauling Institute. "The body sees them as foreign compounds and modifies them for rapid excretion in the urine and bile"......... Posted by: Erica      Read more         Source

Sun, 04 Mar 2007 14:14:41 GMT

Pulmonaria rubra 'Redstart'

Red lungwort is native to southeastern Europe. A popular garden plant for many centuries, it can now be found as an introduced exotic in places such as Finland and Poland. Unlike the other dozen or so species of Pulmonaria, red lungwort does not have blue flowers (hence the Latin and common name).

''Redstart'' red lungwort was evaluated by the Chicago Botanic Garden in its Appraisal of Pulmonaria for the Garden (PDF) and ranked as “fair” or three stars out of four. If you''re considering this early bloomer (or any other Pulmonaria) for your garden, it would be worthwhile to read the evaluation – it grades over fifty species and cultivars. The BBC Gardening site also has a small amount of information specific to ''Redstart''.

Posted by: Jeslin      Read more     Source

February 11, 2007, 9:32 PM CT

New mechanism for nutrient uptake discovered

Stanford, CABiologists at the Carnegie Institution's Department of Plant Biology have discovered a new way that plant cells govern nutrient regulationneighboring pore-like structures at the cell's surface physically interact to control the uptake of a vital nutrient, nitrogen. It is the first time researchers have observed that the interaction of neighboring molecules is essential to this regulation. Since plants, animals, bacteria, and fungi all share similar genes for this activity, the researchers think that the same feature could occur across species. The discovery, reported in the February 11th on-line edition of Nature, has widespread potentialfrom understanding human diseases, such as kidney function, to engineering better crops.

"Every cell in every organism has a system for bringing in nutrition and expelling waste," explained lead author Dominique Loqu. "Some are through pore-like protein structures called transporters, which reside at the surface of the cell's outer membrane. Each pore is capable of transporting nutrients individually, so we were really surprised to find that the pores simply can't act without stimulation from their neighbors".

In earlier research the Carnegie scientists, with colleagues, identified the genes responsible for initiating nitrogen uptake in plants. That identification has helped other scientists find the relatives of these genes in a variety of species from bacteria to humans. In this study, the researchers wanted to identify how ammonium transport is regulated.........

Posted by: Erica      Read more         Source

February 11, 2007, 8:52 PM CT

Grape expectations for healthier wine

A new technique that uses ozone to preserve grapes could help prevent allergies and boost healthy compounds at the same time, reports Jennifer Rohn in Chemistry & Industry, the magazine of the SCI. The same technique could be used in the wine-making process to produce healthier wines without the added sulphites that can cause asthma and other conditions in some people.

Mass-marketed grapes can remain in storage for months and are commonly treated with sulphur dioxide to prevent decay. Eventhough the sulphur dioxide is effective, it is corrosive and can cause severe allergic reactions in some people. Wine-makers have a similar problem in that the sulphites added to wines to prolong their shelf-life and allow them to age can make their wines unpalatable to some drinkers.

Francisco Artes-Hernandez and his team at the Technical University of Cartagena in Spain compared several different preservative methods with a new technique that involves exposing macroperforated packages of grapes at 0 degress C to cycles of 0.1 micro liters per liter of ozone. They observed that ozone therapy was 90% as effective as SO2 at preventing decay. In addition, ozone-treated grapes had up to four times more antioxidants than untreated grapes (Journal of the Science of Food and Agriculture, doi 10.1002/jsfa.2780).........

Posted by: Erica      Read more         Source

January 26, 2007, 5:10 AM CT

Genetically Modified Crops On Developing Countries

A new study in the recent issue of Current Anthropology explores how the arrival of genetically modified crops affects farmers in developing countries. Glenn Davis Stone (Washington University) studied the Warangal District of Andhra Pradesh in India, a key cotton growing area notorious for suicides by cotton farmers. In 2003 to 2005, market share of "Bt cotton" seeds rose from 12 percent to 62 percent in Warangal. Bt cotton is genetically modified to produce its own insecticide and has been claimed by its manufacturer as the fastest-adopted agricultural technology in history.

Monsato, the firm behind Bt cotton, has interpreted the rapid spread of the modified strain as the result of farmer experimentation and management skill - similar to mechanisms that scholars cite to explain the spread of hybrid corn across American farms. But Stone's multiyear ethnography of Warangal cotton farmers shows an unexpected pattern of localized cotton seed fads in the district. He argues that, rather than a case of careful assessment and adoption, Warangal is plagued by a severe breakdown of the "skilling" process by which farmers normally hone their management practices.

"Warangal cotton farming offers a case study in 'agricultural deskilling'," writes Stone. The seed fads had virtually no environmental basis, and farmers generally lacked recognition of what was actually being planted, a striking contrast to highly strategic seed selection processes in areas where technological change is learned and gradual. Interviews also provided consistent evidence that Warangal cotton farmers prefer trying new seeds - seeds without any background information whatsoever - to trying several strains on smaller, experimental scales and choosing one for long-term adoption.........

Posted by: Erica      Read more         Source

January 15, 2007, 7:36 PM CT

Acianthera Casapensis

Species from Colombia, Ecuador, Peru, Bolivia and Venezuela, found in wet forests from 600 to 2800 meters.

Synonym: Pleurothallis chamensis.........

Posted by: Erica      Read more         Source

January 15, 2007, 7:25 PM CT

Colchicum sp

A thank you to Hampshire, England's "Souren" for sharing this photograph via the UBC Botanical Garden Forums. These photographs were taken in September of 2006, in the Kharkiv University Botanical Garden (Ukraine). Much appreciated!

The alkaloid colchicine was first derived from plants in the genus Colchicum, hence the name. In addition to the medicinal uses outlined in the link, colchicine is extremely important in plant breeding research. If applied properly, a colchicine therapy can lead to a doubling of chromosomes in (half of the) gametes, resulting in offspring that are polyploid, or plants that have more than two similar sets of chromosomes.

Polyploidy is important for plant breeding in two respects. First of all, polyploids tend to be more robust than the diploid progenitors. As noted in the Wikipedia entry on polyploidy, a number of important crops were (unintentionally) bred to be polyploid: apple, banana, durum, maize, cotton, potato, tobacco, strawberry, sugar cane, etc. Compare wild strawberries to domesticated varieties, and you'll understand what's meant by more robust! Colchicine, by helping to induce polyploidy, can help create new ornamental or food varieties of plants. A second use of colchicine in plant breeding work is to overcome hybrid sterility, as is done with triticale.........

Posted by: Erica      Read more         Source