How do fungal and bacterial plant pathogens enter plant roots and how does the plant respond?
In order to cause disease in plants, fungal and bacterial pathogens in soil must enter the plant roots. Most plants are resistant to the entry of most pathogens. To enter a plant root the bacteria or fungi must first be present in the rhizosphere of the plant. It then uses molecular signals to recognise whether the plant root is susceptible to entry or not. The pathogen attaches to the root surface possibly by the use of hair-like structures and enters the root. Some pathogens enter through areas that have been damaged by animals and some fungi and bacteria produce enzymes that dissolve the chemical compounds that make up the cell wall. Once the pathogen is in the plant cells, the plant may try to prevent its spread by producing chemical or physical barriers. These procedures may confine the pathogen to only a prtion of the root. back to top Question 5: What is biological control? Plant disease can be controlled in a number of ways. When chemicals such as fungicides are used to control
