CAULIFLOWER MOSAIC VIRUS K R.pptx

CAULIFLOWER MOSAIC VIRUS K R.pptx

1. CAULIFLOWER MOSAIC VIRUS K R MICRO NOTES 1

2. Mosaic plant diseases are common diseases that occur during warmer months which are caused by plant mosaic viruses. These plant mosaic viruses are identified in plants based on their “mottling” and discoloration of leaves. Viruses may also cause leaf deformity, smaller produce and stunted growth. This could lead to plant death and a reduction of crop production which is why the study of mosaic viruses are essential to improve agriculture by both quantity and quality. Cauliflower Mosaic Virus (CaMV), specifically, effects the Brassicaceae family and impacts a host range including crops such as broccoli, cabbage, cauliflower and turnips. Cauliflower mosaic virus is classified as a Group VII pararetrovirus. This means the virus requires transcription from its DNA genome to RNA and then reverse transcriptase to transcribe RNA back into DNA genomes in order to produce progeny virions INTRODUCTION K R MICRO NOTES 2

3. It was the first plant virus discovered to utilize a DNA genome and replicate via reverse transcriptase. Cauliflower mosaic virus is usually transmitted from plant to plant via aphid feeding, where virions make their way to insert themselves into the plants nuclear envelope where they inhibit growth and structure of the host. Cauliflower mosaic virus has been negatively impactful worldwide. Previous studies have shown that CaMV cause a reduction of 25-59% sellable cauliflower heads in Brittany, France as well as a reduction of 60-90% of sellable turnips in the Czech Republic. Breakouts of disease can be devastating to agriculture and national economies. Studying and researching this virus could prevent disease and possibly stop the next potato famine of the cauliflower plant. K R MICRO NOTES 3

4. Cauliflower Mosaic Virus possesses a highly sought after efficient promoter for gene transcription that can be used in an effort to produce transgenic plants. Transgenic plants are used in order to receive benefits such as producing better yield, quality as well as resistance to insects, diseases and herbicides.Currently, about 10% of cruciferous vegetables are infected with Cauliflower Mosaic Virus in order to give the host plant pesticide resistance. K R MICRO NOTES 4

5. ETIOLOGY In order for plant viruses to enter the host’s genome, it must enter via mechanical transmission. This is because cell walls are too thick for some viruses to penetrate so they rely on transmission through broken cells, animal vectors or through their own seeds. For Cauliflower Mosaic Virus, Aphids are the most common vector for infection. Aphids possess a needle-like mouthpiece that allows penetration into plants. Aphids then ingest the plants nutrients and sap while also leaving saliva behind in the plant. This saliva can infect the plant if the aphid contains a virus coming from a plant that was ingested beforehand. K R MICRO NOTES 5

6. The specific aphid that transports cauliflower mosaic virus is the species Myzus  persicae  . These fully grown insects grown to be 1.5-2 mm at maturity. They can reproduce at very fast rates and appear during the warmer months to feed on plants. They are polyphageous, which means there is an array of plant species they are able to feed from. Relating to disease, Myzus  persicae  are known to be able to carry over 100 different types of disease such as cauliflower mosaic virus. Their poisonous saliva can transmit a vast array of diseases from species to species of plant that it chooses to prey on. K R MICRO NOTES 6

7. CaMV is a widespread virus in temperate regions and can cause significant loss in Brassicaceae crops, especially in cases of co-infection with other viruses.  SYMPTOMS CaMV can affect plant development, especially in early infections, and the production of flowers can be blocked. Low seed yields have also been reported from plants with CaMV infection  The virus can induce a range of systemic symptoms, such as chlorosis (loss of green leaf color), mosaic (patches of light and dark green on leaves), vein clearing (abnormal clear or translucent color of veins), and/or stunting K R MICRO NOTES 7

8. K R MICRO NOTES 8

9. CONTROL In order to defend against viral infection of cauliflower mosaic virus, plants must depend on their natural defenses or risk death. In a situation using cauliflower as an example, in farms having cauliflower as a cash crop, the risk of viral infection is very high. It is because they are all grown in proximity and in the same conditions where random mutation is not favored, it would not be favorable to viral resistance. In this scenario, breeding with mutated cauliflower would be the best chance of gaining resistance. Plants also must rely on their own immune systems. If a plant can utilize its ability to interfere with gene expression then virions will stop being replicated inside of the host. The plant is able to recognize foreign mRNA and stop gene expression before the plant continues producing for the virus. There is no cure for cauliflower mosaic virus. Once a plant is infected, then it is too late. Prevention is the only way to prevent agricultural or gardening losses. K R MICRO NOTES 9

10. Since cauliflower mosaic virus is usually spread by aphids, so any sort of pest control can be beneficial in reducing infection. Netting or pest control products may keep virus carrying insects at bay. Since this virus can be transported through any opening in plants such as abrasions or cuts, disinfecting tools, equipment and anything that contacts plants will reduce infections. Some things such as damp conditions may also contribute to faster/easier transmission of cauliflower mosaic virus. It is best to get rid of infected plants immediately to reduce exposure to plants nearby. Also, get rid of seeds coming from infected plants because CaMV could be transmitted to plant offspring. Keeping weeds away from the farm or garden can also eliminate virus harboring organisms. Finally, there are varieties of plants with resistance to caulimoviruses that are unable to get infected in the first place K R MICRO NOTES 10

11. REFERENCE https://microbewiki.kenyon.edu/index.php/Cauliflower_mosaic_virus https://www.frontiersin.org/articles/10.3389/fsufs.2020.00021/full http://www.slideshare.net/BooapthiN/cauliflower-mosaic-disease?from_m_app=android Text book of microbiology – Vol III –Chandrakanth kelmani , edited by –prof.S. B sullia K R MICRO NOTES 11