Green Biotechnology - A advanced technique to generate GM Ornamental Plants

Written by G. Akhtar - Dr. R. M. Balal - M. A. Shahid - T. Abbas - A. Akram

Biotechnology is not applied in the field of medical but also has a significant role in agriculture. The processes and methods of agriculture have been refined by the use of biotechnology to increment the productivity. Biotechnology has also revolutionized research activities in the area of agriculture which includes the following: (i) plant cell, tissue and organ Culture(ii) genetic engineering leading to transformation followed by regeneration of plants to give genetically modified plants carrying desirable, traits like disease resistance, insect resistance and herbicide resistance; eventually this may also be used for increasing photosynthetic efficiency, nitrogen fixing ability, improved storage proteins, hybrid crops, crops for food processing etc. The development of genetically modified foods and other agricultural biotechnology products has generated significant public debate. The potential for creating foods enhanced for health benefits or increasing crop yields was tantalizing, but there was also widespread concern about the technology’s health and environmental risks. The Pew Initiative on Food and Biotechnology spotlighted policy issues arising from these discussions and served as a credible, honest broker, bringing together people with differing viewpoints to examine the opportunities and challenges of agricultural biotechnology.

Green biotechnology is biotechnology applied to agricultural processes. An example would be the selection and domestication of plants via micropropagation. Another example is the designing of transgenic plants to grow under specific environments in the presence (or absence) of chemicals. One hope is that green biotechnology might produce more environmentally friendly solutions than traditional industrial agriculture. An example of this is the engineering of a plant to express a pesticide, thereby ending the need of external application of pesticides. An example of this would be Bt corn. Whether or not green biotechnology products such as this are ultimately more environmentally friendly is a topic of considerable debate.

Ornamental plants are grown as flowering plants in the gardens or as houseplants. Their most common features are flowers and others are leaves, bark, stem, and fruits of different color, size and fragrance. These are used for decoration of office, garden, house, roadside or any thing and place due to their decorative purposes and keep the people close to nature. Flowers of some ornamental plants are also used for extraction of valuable essential oils. Due to these reasons demand of ornamental plants is increasing with the passage of time and plant breeder are trying to produce new varieties of different attractive colors, more fragrance, longer vase life and resistance against pests and diseases but it is a very tedious process and takes many years to produce genetic modification.

Genetic engineering in combination with plant tissue culture is an efficient way of producing genetic modification in ornamental plants through alteration in genetic material by artificial means and is different from the traditional breeding because it does not need selection and pollination in the field, which takes many years to produce genetic modification with very little success. In this technique desired genes is isolated from a plant and transferred in the plant to produce desired characters.  There are two methods of gene transfer first is vector mediated transfer and second is direct gene transfer. In vector-mediated method of transformation a vector Agrobacterium is used, which a soil bacterium is causing outgrowths (galls) on the plants. This bacterium transferred the genes in the root cells of the plants to produce gall. Due to this ability it is used as vector. The gene of interest is isolated and transferred in the DNA (Deoxyribonucleic acid) of Agrobacterium, which infect the desired plant cell and transferred the desired gene in the plant cell. In the direct transfer method desired genes are transferred in the plant with out the use of vector. It has different methods like electroporation of protoplast, in this method pores are made in the protoplast membrane and through these pores plasmid DNA transferred in the protoplast, which is used to regenerate the plants. Microinjection, in this foreign DNA is transferred in the nucleus of protoplast by injection pipette of 0.2 mm diameter and protoplast is cultured to produce plants. Laser microbeam, in this UV-laser microbeams are used to produce pores in the membranes and DNA from the solution is entered in the cell through these pores. Electroporation into embryos, DNA is delivered in the embryos by electroporation. Particle bombardment, this is most desired used method of transferred because it can deliver DNA in cells, tissue or organs. In this method DNA particles are coated with gold or tungston and transferred by a gene gun, which accelerate particles to penetrate into the tissue.

Plant tissue culture also has very important role in the production of genetically modified plants because after the transferred cell or tissue are need to regenerate into new plant and production of more plants from that genetically modified plant. There are different direct and indirect regeneration techniques of plant tissue culture. In direct techniques direct shoots and roots are developed from the explants e.g. meristem culture, in which meristem is used to shoot and roots. Nodal culture, in this node is used to produce plants. In indirect methods first callus and then from callus shoots and roots are developed e.g. leaf, ovule, anther, petal and cell culture. After gene transfer in the cells or tissue of desired, callus is produced from these transformed cell which further form somatic embryos then shoot and roots. From this single plant many plants produced by mass propagation through plant tissue culture techniques.

Flower color is most important and attractive trait of ornamental plants. People want variation in flower color of different ornamental plants. To fulfill the growing need of different colored ornamental plants, genetic engineering is playing is role and successfully genetic modifications have been in many ornamental plants like rose, gerbera, petunia, chrysanthemum, carnation, torenia and lisianthus by inducing changes in anthocyanin (a class of flavonoids produces pink, red, violet and blue color in flowers) and Carotenoids (a class of isoprenoids produces yellow, orange and red color in flowers). Flower fragrance is also a very important trait to increase the value of ornamental plants. Fragrance of flowers is due to volatile compounds, which are secondary metabolites such as terpenoids, phenylpropanoids and derivatives of fatty acids. Few genes have been identified which directly involved in production of fragrance in the flowers of ornamental plants. As linalool synthase (lis) gene responsible for the production of fragrance was introduced in petunia and carnation but it does not produce olfactorally detectable changes in the fragrance of these flowers. Vase life is also desirable character of ornamental plants. Work has been done on genetic modification of many ornamental plants to increase their vase life like carnation, petunia and carnation etc. Insects and diseases cause major losses to ornamental plants. Different fungal, bacterial and viral pathogens attacked on the ornamental plants and in response to their attack chitinases and glucanases are produced in the plants. So the over production of chitinases and glucanases by genetic modification can produce resistance in the plants. More resistance has produced in against fungus in petunia and against blackspot in roses by genetic modification. From more than 30 years cry gene of Bacillus thuringiensis has been using for creating resistance in plants.

There is a great need of genetic modification in ornamental plants in our country to fulfill the growing needs and to earn a lot of by their export. It is a need of day to expand the work on genetic modification because we invest a lot of to import ornamental plants. Now work has been started to developed protocols for invitro regeneration of different ornamental plants (rose, gladiolus, carnation etc) in plant tissue culture, which is a step in this response. For this our government should develop more high quality lab. and private sector should also involved in this work, more short courses should arranged to produce skilled labour.

Original Article Here

A Growing Problem: Notes from the ‘Superweed’ Summit

Superweeds—the “weeds that man can no longer kill!”—have been in the news for several years. All across the Midwest and Southeast farmers have been photographed and filmed standing in fields surrounded by the giant plants. They bemoan the cost of pesticides and point to industrial rows of crops that don’t have a chance when up against feisty weeds that grow up to three inches a day.

Superweeds have been especially likely to appear alongside genetically engineered (GE) crops, which are engineered to withstand large amounts of pesticide and herbicide use. And these weeds show no sign of going away any time soon.

That’s why scientists and researchers from land-grant universities, the U.S. Department of Agriculture (USDA), and representatives from several industry and trade groups met at last week’s summit to strategize about the problem.

A few speakers boasted about the efficiency of modern-day farming and the fact that today’s agriculture requires fewer farmers on more acres. But missing from their analysis was the long list of consequences: from degradation of the environment, to health risks from increased chemical use and, ironically, superweeds themselves.

Those who did address the weeds tended not to see them as a result of that impressive modern agriculture. Take Michael Owen, an agronomist from Iowa State University, for instance. In his talk, he contended that superweeds are neither an herbicide problem nor a GE crop problem, per se, but a behavioral problem. This analysis puts the blame on farmers for overusing herbicides. Yet the resistance situation first arose when biotechnology companies pushed herbicides like glyphosate (or Roundup) on farmers as the silver bullet to weed management without educating them on the ramifications of their ubiquitous use. And the practice of using just one herbicide year after year would not have occurred if it weren’t for the aggressive promotion of the Roundup Ready line of GE crops (engineered to tolerate Roundup).

There was some talk of non-chemical solutions by Michael Walsh from the University of Western Australia, who spoke about that country’s serious problem with a weed that has developed resistance to several herbicides. Australian researchers designed a few different weed seed control methods that destroy the seed reserves, eliminating upwards of 95 percent of the seed before it is able to germinate. But it was made very clear by the U.S. farmers attending the summit that going back to traditional methods, like cultivation, would be tough. There was little mention of organic weed management techniques such as crop rotation or the use of cover crops.

But exhausting chemical tool after chemical tool in an arms race against herbicide resistant weeds is not only not sustainable, it’s not working. And despite the fact that chemical solutions are the cause of cross-resistance and multiple resistance in weeds, the need for more chemical solutions was still at the forefront of the discussion.

Strikingly missing from the conversation that day was any talk of the next round of GE crops now in the pipeline, like Dow’s 2,4-D corn and Monsanto’s dicamba soybean, which have both been designed to be resistant to more than one herbicide at once. A full 13 out of 20 crops in the queue awaiting USDA’s approval have what are called “stacked herbicide resistance traits.”

These crops, once approved, will likely result in the use of many more gallons of herbicides and the evolution of even more powerful superweeds that will be resistant to many different herbicides—making them harder and harder to manage. Formulating new varieties of crops to withstand applications of harsher chemicals may be business as usual for these scientists and the companies they work for, but it’s an approach that ignores the underlying issue.

The final speaker at the summit was Iowa State University President Steven Leath, who said he believed that using a “land-grant approach” involving public-private partnerships will help solve this complex problem. This approach is not surprising coming from Leath; Iowa State is known for its relationships with corporations (especially Monsanto), and its agronomy department received around half of its funding from private-sector donors from 2006 to 2010. Iowa State’s campus is even home to a Monsanto Student Services Wing in the main agriculture building.

The superweed problem is one that should be attacked with preventative strategies based in weed biology and independent, interdisciplinary creativity. But partnering with biotechnology companies will likely only result in biotech solutions.

We have the opportunity to see superweeds as a wake-up call and a strong argument for pulling agriculture off the chemical treadmill to which it is bound. But to do that, public research—free of private sector influence—must be funded in order to give farmers better alternatives and to shift the focus away from the current chemical arms race against weeds.

Originally published on Grist

Herbicide Injury to Corn Increases

US - During the past week, the number of observations and inquiries related to corn injury from herbicides increased, said University of Illinois associate professor of weed science Aaron Hager.

Instances of corn injury appear to be fairly widespread across the state. Direct application of postemergence herbicides and persistence of herbicides applied last season appear to be responsible for much of the injury.

"Many postemergence corn herbicides routinely cause some corn injury," said Professor Hager. "Some growers, however, have the impression that this year there is a bit more injury than usual."

Professor Hager said that several factors can affect the sensitivity of corn to injury from postemergence herbicides, including:

Hybrid: Hybrids have varying sensitivity to herbicides labeled for use in corn. For example, some corn hybrids are sensitive to specific ALS-inhibiting herbicides and tend to exhibit considerable injury following herbicide application. Many corn herbicide labels (especially labels of postemergence corn herbicides) carry warnings that certain corn hybrids could be sensitive to the active ingredient.

Environmental conditions: High air temperatures and relative humidity levels favor rapid absorption of foliar-applied herbicides, but some environmental conditions can induce crop stress, slowing the rate at which the crops metabolize the herbicide and leading to increased herbicide-related injury. For example, cool air temperatures and wet soil can induce crop stress.

Spray additives: Crop response may be enhanced when spray additives are applied with a postemergence herbicide or tankmix combination because of the increased rate of herbicide absorption into the plant. Be sure to read all label suggestions and precautions related to spray additives that should be either included or avoided when applying herbicides postemergence.

Contamination: Herbicide residues from prior applications may be applied inadvertently with the postemergence corn herbicide. These residues, either alone or in combination with the postemergence corn herbicide, may enhance the amount of corn injury. The type of contaminant and the dose at which it is applied affect the severity of the corn response to spray contamination.

Soil residues of herbicides applied during the previous growing season (carryover) appear to be another source of corn injury. Herbicide persistence in the soil, and the rate of chemical or microbial degradation, are influenced by many factors, including the specific chemistry of the herbicide and edaphic factors.

The soil pH is a critical factor affecting the persistence and degradation of many herbicides, including sulfonylurea and triazine herbicides, because it affects the rate of chemical degradation via hydrolysis. High soil pH (7.0 or more) may slow the dissipation of certain herbicides by reducing the hydrolysis rate. Even when soil moisture is adequate, triazine and sulfonylurea herbicides degrade more slowly in soils with high pH.

Soil moisture also influences the efficacy and persistence of soil-residual herbicides. Populations and activity of soil microorganisms that are responsible for microbial degradation of herbicides are greatly reduced when soil moisture is limited. Moreover, more herbicide is adsorbed to soil colloids in dry soils, making it unavailable for plant uptake and degradation by soil microbial populations.

"The very dry soil conditions encountered during parts of the 2011 growing season likely slowed the degradation of some soil-residual herbicides, particularly those degraded by soil microorganisms," said Professor Hager. Dry soil conditions early in 2012 allowed for unusually early corn planting, which in some instances occurred before the end of the rotational interval of the herbicide used in 2011.

Professor Hager said there have been several reports of corn injury that appear to be caused by fomesafen carryover. Veinal chlorosis or necrosis, which causes a striping effect on the leaves, is the most common of these symptoms.

"In some instances, the leaf veins almost appear clear or transparent, but the root system of affected plants usually shows no symptoms unless the foliar symptoms are extremely severe," he explained.

Because of the fomesafen's soil persistence and corn's sensitivity to fomesafen residues, the labels of most products that contain it, including Flexstar, Flextar GT and Prefix, indicate a 10-month rotational interval for corn.

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