Aluminum induces cross‑resistance of potato to Phytophthora Infestans This article is about an experiment done to try to see if Aluminum can cause resistance in potatoes to a disease. Aluminum is commonly found in arid soils which accounts for 35% of all farmable on earth. The aluminum (specifically Al3+) targets the roots of the plants and causes stunted plant growth and abnormal root formation. THis causes stresses in the plant which could lead to cross resistance. This immunity has led to some plants to develop cross resistance to diseases. THis has happened before in the plant, an example is the fact that ozone induces resistance to the tobacco mosaic virus in tobacco plants. This phenomenon is what is being tested for in potato plants. Potato plants will be subjected to infections from Phytophthora infestans. They sprayed the plant with bacterial cultures in order to infect the potato plant with the P. infestans. This was done by spraying the plant the P. infestans zoospores in a liquid suspension. After the plant was sprayed, it was moved to a room with 100% humidity in the dark for 12 hours at 18 degrees Celsius. After the twelve hour, they were moved to a growth chamber under controlled conditions. The plants were inspected for infection at the 24,48,and 74 hour mark. THe amount of infection was determined by observing the discoloration on the leaves of the plant. The level of Nitric Oxide in the plants were measured by taking samples of the root and the leaves. A dye was applied to the nitric oxide in order for it to be more clear when viewed. Salicylic Acid(SA) was measured was by measuring 0.5g of plant tissue. The tissue was ground to a fine powder with liquid nitrogen. The acid was then extracted twice with Methan... ... middle of paper ... ...e involved in the plants carbohydrate metabolism. This response causes the plant’s cell walls to be rearranged and strengthened. THis would increase the plants resistance to infection and the uptake of harmful chemicals. Several other chemicals which were involved in either signalling or as part of the defense response in plants were also seen to be at increased levels. What this means is that there is a proven correlation between aluminum exposure and a reduction in blight symptoms caused by P.infestans. It also was shown that the plants were also quicker to respond to other stresses. This means that certain strsses(in this case the aluminum) act as priming agents forthe defense response. SA which has been shown to have an important role ina plant’s defense responses also had an increased amount of production, which helped increase the plants immune response.
The basis for the symbiotic relationship in these species is complex. The infection of the host cell by rhizobia occurs within the plant’s root nodules. Bacteroides, gram-negative anaerobic bacteria, are isolated from the host cell by a peribacteroid membrane; the membrane between the plasma membrane of the cell and the membrane of the bacteroid. The bacteroid contains differentiated rhizobia, which are able to fix nitrogen due to the supply of carbon from the host plant. Sucrose is delivered to the nodules of the root via the phloem, where it is cleaved by suc synthase, and enters the Krebs cycle. The product of glyco...
Burpee, Lee, and Richard Latin. 2008. "Reassessment of Fungicide Synergism for Control of Dollar Spot." Plant Disease 92.4: 601-06.
...ut 10%. This is despite of obtaining high virus titers. Symptomless plants are regarded as carriers of PVX and are an important source of infection. Under more severe conditions, necrotic streaks and severe mosaic, crinkling and rugosity of the leaves can occur. Especially upon mixed infections with potato virus Y (PVY), the yield loss can be up to 50%.
In this laboratory experiment, the rate of photosynthesis was measured through the use of the “floating leaf disk technique.” The leaf disks were placed into a syringe and the O2 and CO2 in the mesophyll layers of the leaves were removed and then replaced with sodium bicarbonate or water, causing the leaves to sink to the bottom of the container. If one determines the number of leaf disks rising to the top as a result of an increase in oxygen gas in the mesophyll cells, then the rate of photosynthesis is able to be measured because O2 is a product of photosynthesis. The first step of this experiment was a feasibility study of the variance in the photosynthetic activity of the leaf disks in both water and bicarbonate solutions. After five minutes of light exposure, all of the leaf disks in the bicarbonate solution (10 disks) had ...
The issue written in this article is regarding the banning and lack of approval for blight-resistant potatoes in the european union. Late potato blight, a potato disease caused by the the eukaryotic microorganism phytophthora infestans, is a significant cause for loss of crop and yield by potato farmers. Looking back to the past, the blight was responsible for the catastrophic Irish Great Famine of the 1840s causing eradication of their main food source, potatoes. As a result of the blight, potatoes become rotten and unsafe for human consumption. Late potato blight today is still a serious issue because it has caused the loss of $5.9 billion dollars of potatoes worldwide annually.By engineering blight resistance into potatoes, scientists have hoped to increase the yield and productivity of potato crops affected by this devastating disease. However, the attempts of the scientists are met with strong resistance by anti-GMO activists and lobbying groups, who are intent on food as naturally pure as possible. In consequence of not using genetically modified potatoes, the farmers are forced to use costly pesticides in an attempt to control the blight. With the human population rapidly increasing, it is essential that all measures be taken to increase food/crop yield in order to prevent starvation and hunger caused by the overpopulation. The battle between agricultural researchers like Simplot and the anti-GMO lobbying group GeneWatch is a controversial one that must be addressed by this generation and future generations.
Sulfur may enter the plants in few ways such as enter through the roots in form of sulphate ion, dissolved in water with form of sulphate ion or in form of gaseous sulfur dioxide (SO2) which can penetrates into the leaves through the stomata. But both of it can be utilized by plants through the metabolism of normal sulfur, although the limited pathway via cuticle was proof. However, the aperture of the stomata was largely controlled by conditions of the environment, such as temperature, ligh...
The another devastating abiotic stress which is considered to be highly responsible worldwide for decreasing yield and quality of crop productivity is drought (Lambers et al. 2008 ; Moghadam et al .,2011; Mohsen Pourgholam et al.,2013 ; M. Farooq et al., 2012; Abolhasani and Saeidi, 2004 ; Monjezi et al., 2013).It harms plant growth and development and reduces crop growth rate and also affects biomass accumulation. Generally, in crop plants drought severely affects the cell division and expansion, elongation of root, leaf size, proliferation of root and inhibition of shoot growth (Sharp & Davies 1989; Spollen et al.,1993;Yamaguchi et al.,2010). Furthermore ,it also badly hampers all kinds of plant functions and physiological and biochemical traits such as mineral elements, carbohydrates, free radicals, ions, hormones, lipids, and nucleic acids (HongBo et al., 2005; Yasar et al., ; Moghadam et al .,2011,Mohsen Pourgholam et al,2013) .The transportation of nutrients from the roots to the stem severely get affected by drought as the rate of transpiration is reduced and damage of active transport and membrane permeability take place (Viets, 1972; Alam, 1999; Yasar et al ). Simultaneously, due to decrease in soil moisture, problem occurs with the low distribution of absorbed nutrients by the plant roots in the soil (Alam, 1999; Yasar et al ). More importantly, drought leads to rise in generation of reactive oxygen species (ROS) due to energy accumulation in stress condition of plants (Smirnoff 1993; Asada 2006; Waraich et al.,2011).Drought diminishes photosynthetic carbon fixation primarily through restraining the entrance of CO2 into the leaf or by reducing metabolism (Smirnoff 1993; Loggini et al., 1999; Ap...
The potato famine of 1846 was one of the biggest natural disasters in Irish history. The “explosive disease” said William Fry, Ph.D., caused by Phytophtera infestans, is a condition that prevents growth and destroys the plant by disease. P. infestans is a fungus-like pathogen that infects and destroys the leaves, stems, potato seed and the potato itself, turning it black and slimy (Craig, 1998). The first signs of blight are when leaves get brown specks on them that start to get white, hairy growth around them (Damsker, n.d.). In addition, leaves and stems withered very quickly. This if followed by a terrible smell. It spreads as a spore and grows rapidly in moist, warm and humid conditions. Today, the blight disease still affects potato crops. However, an application of the plant fungicide, metalaxyl, or copper sulfate mixtures and pesticide will prevent and eliminate or, at least, decrease the possibility of its appearance (Daly, 1996). In fact, according to Gibbon’s article in 2013, the pathogen and its host of dried leaves ar...
Plant hormones are certain chemicals present in plants that control plant growth and development by affecting the division, differentiation, and elongation of cells. (Campbell, 2008) Each hormone has multiple effects depending on its site of action, its concentrations, and the developing stage of the plant. (Campbell, 2008) Auxin is a plant hormone that is synthesized within the apical meristems and young leaves of a growing plant. Auxin stimulates stem elongation when it is present is low concentrations. It promotes the formations of lateral and adventitious roots, regulates development of fruit, enhances apical dominance, functions in gravitropism and phototropism, promotes vascular differentiation, and retards leaf abscission. Gibberellic acid is one of several plant hormones that govern a plant’s growth. Gibberellins allow for stem elongation in plants. Plants without enough of this hormone tend to grow short or stunted. This chemical is high in the element potassium, which is one the main components of plant fertilizer and very important for plant growth on its own. The...
Plant defences are those mechanisms employed by plants in response to herbivory and parasitism. According to Hanley et al. (2007), “the tissues of virtually all terrestrial, freshwater, and marine plants have qualities that to some degree reduce herbivory, including low nitrogen concentration, low moisture content, toxins or digestibility-reducing compounds”. The type of chemical defence may be species specific (Scott 2008). The defences that plants possess may be in the form of chemical production or in the form of physical defences such as thorns or spikes and even through reinforced, rigid leaves. “The compounds that are produced in response to herbivory can either have a direct effect on the attacker itself (e.g. toxins or digestibility reducers), or serve as indirect defenses by attracting the natural enemies of the herbivores” (Bezemer & van Dam 2005). This essay will focus on chemical plant defences and in particular the effects of terpenes, phenolics, nitrogen-based defences as well as allelopathy in plants.
When there is water deficiency in plants, the concentration of abscisic acid in plants’ cells increases triggering the closure of stomata. Karp (2009) stated that “abscisic acid binds to a GPCR in plasma membrane of guard cells” (p.638). The receptors then activate several pathways in response to this condition. This attachment causes the opening of Ca2+ channels which transfer Ca2+ from vacuole into cytosol. At ...
The "cardboard" tomato problem illustrates a larger problem in agriculture - crop spoilage associated with the predations of insects and fungi and with shipping. We saw that picking fruits such as tomatoes while they are green and chemically ripening them is a solution to some of the spoilage problem in crops, while using other chemicals can prevent some damage by pests. However, these chemicals often create environmental hazards in areas where they are used, and pests can often develop resistance to chemicals used to destroy them, making the release of even more pesticides and fungicides int...
Fertilizers are essential to modern industrial agriculture. Two of the most important plant nutrients are nitrogen and phosphorus. Nitric acid, phosphoric acid, ...
Genetic engineering enhances plant resistance to drought, salinity, disease, pests and herbicides. The aim is to try and enhance the growth, productivity, nutrient value, and chemical composition of the plants. Chemicals are constantly being developed or improved to enhance the competitiveness and adaptability of crops, and to kill the parasites and weeds which plague the agricultural sector. . This however is not always good as the plant and the pests then become resistant to these new chemicals defeating the purpose of it being used. The new chemicals which are produced to kill these strong pests and weeds may be more harmful to other plants and remove nutrients within the soil in turn reducing the yield of agricultural crops. The benefits of these characteristics are seen in Argentina according to Pelletier (2010) as they use glyphosphate resistant soybean which allowed the comeback of this crop, as the so...
When studying plant nutrition, it is important to analyze the sources of the nutrition. Plants absorb their nutrients using their roots in the soil, however soil is not a uniform nutritive source. The plant’s wellbeing depends greatly on the quality, composition, and thickness of the soil. To help categorize such a broad topic, scientists have implemented a naming scheme for the different levels of soil. The first layer is closest to ...