How Can Plants Protect Themselves From Pathogens in Rain

 

    A recent study has revealed that when plants are exposed to rain, hair-like structures on the leaf surface called trichomes recognize the rain as a risk factor for causing disease and activate their immune system to prevent infections. These findings could contribute to the development of methods to protect plants from infectious diseases caused by rain.

    Although water is one of the key essentials for majority of plant life, there are also bacteria that come from these water sources which can harm the plants. Raindrops can contain pathogens, like bacteria, filamentous fungi, and viruses, which can cause disease in plants. Plants have their own immune systems, so when these plants detect pathogens, they express immune-related genes to prevent themselves from being infected. 

    A research team led by Professor Yasuomi Tada and assistant Professor Mika Nomoto of Nagoya University conducted a study using seedlings from Arabidopsis thaliana (common name: thale cress). They found that Ca2+ levels around the trichomes on leaf surfaces increase. 

    Professor Tada says that their findings may be able to artificially improve plants' defensive capabilities against diseases at any time and for any length of time.

Related Article: https://pubmed.ncbi.nlm.nih.gov/15085136/

Bottleneck Effect on the American Bison

         

      In the United States, there were once 60 million American Bison. During a time period in the mid to late 1800's the overexploitation of the animal caused that number to drop to about 325. This severe decrease in population size caused what is known as a "bottleneck effect". These types of events are caused by severe decreases in population size due to environmental or human activity. The results of events like this are usually not one that a species can recover from. Fortunately for this species, in the early 1900s, 5 private ranchers and government agencies worked diligently to make sure this American icon would not go extinct. However, this does mean that today's bison are all descendants from about 100 founders of the current population, and only 4 herds of genetically pure bison live in the United States today.
           A bottle neck effect, like the one seen in the American Bison, can lead to many health problems for future generations. In losing genetic diversity, the future generation of wild bison become more susceptible to things like disease and pathogens. To combat this, ranchers and private government agencies bred the bison with cattle, which produces a hybrid, known as a "beefalo". Unlike other hybrids, this particular hybrid is fertile. This ability to reproduce as a hybrid helped increased population size, and brought the American Bison back to a population size of around 500,000. While 500,000 may seem like a high number, it is nothing compared to the estimated 60 million that once ruled the United States. Of these 500,000, only about 4% are in herds managed for conservation purposes, and roughly 10,000 are actual wild wood Bison. Many of the wild wood Bison are pestered by diseases like bovine tuberculosis, or brucellosis. This might leave you wondering, where are the other 470,000 bison living in the United States? These bison are used in commercial herds for meat, leather, and commercial production. Bison that are commercially farmed are bred for specific purposes, with specific mates. The artificial crossing of these bison, often with cattle, leads the American Bison to be more favorable for production of traits the ranchers find favorable, and not necessarily favorable for the survival of the species.
          While the efforts to conserve the American Bison have made great strides, it still is saddening to think that the American Bison once ruled the United States, and now are essentially held in captive, only bred for profit. The American Bison is an iconic symbol of North America, once roaming from Alaska into Mexico. Now, they roam about 1% of the United States. Thanks to the genetic conservation of a few ranchers in the early 1900's the American Bison is still around.
          This event fascinated me so much because of the dramatic change in population in such a short period of time. The fact that the American Bison exists today is truly a wonder after the slaughter of so many. Even though most of the bison in the wild today are the result of hybridization, it gives me comfort in knowing that someone along the way realized that what was happening to these animals was wrong, and they needed to be saved. I often wonder what the ecological effects of this event have been. Losing almost 60 millions animals in a population is a drastic change to an ecosystem.






https://academic.oup.com/jhered/article/100/4/411/858147
https://www.nps.gov/articles/bison-bellows-12-3-15.htm
http://www.softschools.com/facts/hybrid_animals/beefalo_facts/2695/

Cobwebs Hold Genetic Secrets About Spiders and Their Prey

Scientists have discovered traces of DNA stuck on old spider webs. DNA from both the spider and any other creature that has fallen trap to the spider’s web can be collected from old spider webs. These traces of DNA can be of importance to researchers in the fields of conservation ecology, pest management, etc. Scientists amplified cytochrome oxidase 1, a mitochondrial gene, in order to identify a species that may have been on a spider web. This type of technology allows researchers to collect a number of spider webs throughout an environment to possibly detect the survival of endangers species. It also makes identifying species a whole lot easier and humane when you don’t have to capture and kill an organism.

            I personally believe this type of technology is great. I believe in the preservation of natural wildlife, and to be able to easily identify species of animals in a given environment just by a spider web makes it good for conservation ecologists to work. It is also, however, much more humane to organisms when they don’t have to be stripped from the wild and killed. This article was very interesting, and I would like to further investigate how this type of DNA research is benefiting our wildlife.

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Red Wood Cloning May Help Forest Management

Red wood trees are well known for their incredible size and impressive longevity, but very few

people realize there’s more to the great trees than their size. Red Wood trees are often examined in biology for their cloning tendencies, as they are prone to sprouting entirely new trees from roots, cut branches, and fallen stumps of grown trees. Not much research has looked at the lineages created by these cloning trees, but a recent study at UC Berkley has pioneered this kind of study. Because Red Woods are hexaploid – that’s right, not one or two but six sets of chromosomes in the genome – their lineages are difficult to trace, especially with the chance of mutation taken into account. In the UC Berkley study, DNA was extracted from 770 redwoods and 449 distinct clones were identified. Because redwoods are prized both for their natural preservation and their youthful lumber, understanding the genetics of redwoods could help create healthy forest management options for redwood lumber as well as help in the current actions beign taken to preserve currently growing redwood areas. The head researcher of this study hopes that clonal studies could expand beyond redwoods to other cloning species, as well as help scientists understand the physical structure of forests.