Thursday, January 14, 2010

Time Limit In Name Change After Marriage In Tx

how plants Feel the temperature rise


The plants are extremely sensitive and can detect even the most minimal changes. In a study published in the January magazine
Cell, shows how plants can not only 'feel' the temperature rise, but may increase depending on the temperature coordinate a response suitable cell - through the activation of hundreds of genes e la disattivazione di altri. I risultati possono aiutare a spiegare come le piante rispondono quando si verificano dei cambiamenti climatici e a creare piante da coltura che saranno in grado di sopportare in misura maggiore lo stress dovuto alle alte temperatura, dicono i ricercatori.
" Abbiamo scoperto il principale regolatore di tutto il trascrittoma della temperatura
," ha affermato Philip Wigge del
Arabidopsis thaliana
i ricercatori have shown that a key element of the sensitivity of plants to temperatures, the detection ability is conferred by a specialized histone proteins, known as H2A.Z, which wraps DNA into a more compact structure known as the nucleosome . When temperatures rise, histone H2A.Z allow the DNA to unfold gradually. " When the temperature increases the DNA undergoes a course," says
Wiggi
what allows some genes turn on and off other genes. Wiggi suspect that the alteration nucleosome structure allows access to sites on the DNA to activate certain genes and a repressor of other genes.
"
addition to H2A.Z, the results suggest that the degree of relaxation of the DNA may be sensitive to temperature variation ," the researchers write. " This result suggests a direct mechanism by which the temperature can influence gene expression , as it has been demonstrated that RNA Pol II [the enzyme responsible for transcription of DNA into messenger RNA] not actively invade nucleosomes, but expects the local unwinding of DNA from nucleosomes prima di estendere la trascrizione
.
In questo modo, i geni con RNA Pol II in pausa mostreranno una aumento della  trascrizione a temperature più elevate
".

La scoperta di base potrebbe in ultima analisi avere importanti implicazioni per la sicurezza alimentare mondiale, hanno detto i ricercatori.

Poiché il numero di persone in tutto il mondo continua a crescere e con esso anche lo stile di vita diventa sempre più esigente, " si prevede che l'agricoltura mondiale dovrà incrementare la resa dal 70 al 100% nei prossimi 100 anni ", ha detto Wiggi. "Because of
climate change will be challenging to maintain current yields, not to mention an increase in their
. Crops like wheat are particularly vulnerable to very hot summers and dry, he added, as evidenced by the fact that wheat stocks recently fell to its lowest level in 30 years.
The discovery that the expression of DNA in plants may be altered due to changes in temperature, could be crucial for the production of crops resistant to certain environmental conditions. His team plans to explore this possibility, studying the role of these histone H2A.Z in model plants, which are more closely related to crops.
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Sunday, January 10, 2010

Camera Bagdisney World

Plants can be selfless?


Plants can be altruistic? It seems so. A study published in the '
American Journal of Botany
a eseperimento has shown that plants also have altruistic behavior towards "
relatives."
The concept of altruism has long been debated in philosophical circles, and, more recently, evolutionary biologists have joined the debate. From the perspective of natural selection, any action that improves the survival probability of a relative increases the chance of reproduction of individuals of the same species. Social behaviors, such as the recognition of relatives, and altruism are well known in the animal kingdom, however, even if the plants have the ability to perceive and respond to other plants, their ability to recognize relatives and selfless act was been the subject of few studies to date.
In an article published in the November issue of the Journal of Botany
Guillermo Murphy and Dr. Susan Dudley found that the plant Impatiens pallida

known as the Joint smart glass, herbaceous plant of eastern forests of North America, recognizes his peers and change its behavior in relation to the degree of relatedness of the plants that grow nearby.
Dudley Murphy and selected seeds of Impatiens pallida and have them planted in different pots, each of which could hold the seeds of plants of the same family of plants genetically distant, then manipulated the light radiation and its intensity to see if the strategy to capture more light depended on the degree of relatedness of neighboring individuals. The researchers found different responses from dell'Impatiens depending on whether the plant had grown up with the "relatives" or with foreign plants. To be precise, the two biologists have discovered that the plants which were inbred to common vessels, altered their morphology modeling the growth of its branches so as not to shade nearby plants. An example of how plants have worked with relatives in an attempt to acquire the land and the environment in which to grow all the necessary resources without depriving other plants of the same species of all that they needed to grow. The Impatiens pallida is a plant that typically located in the undergrowth of forests, where the light may be poor, but the soil is usually rich in nutrients. As the plants of Impatiens plants grown together with strangers, they had increased the size of their leaves so as to shade the plants with which they had to compete. Thus, these plants not only have a positive effect on its growth by strengthening their ability to acquire a limited resource, but also negatively affected the growth of their competitors by making shadows and reducing the ability of competitors to capture the light. However, these differences in response based on the presence of relatives or strangers were observed only in those plants grown at close range, to indicate that communication between the roots may be necessary to the recognition of relatives. This study shows that the plants are social organisms, and show that altruism among plants is possible. The I.pallida
recognize relatives from strangers using this information to the so-called kin selection, the set of altruistic behavior among relatives in order to increase the fitness of a GroupThe of individuals who share similar genomes.
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