Using their molecular block, plants are able to predict when infections are most likely to occur and use this information to better coordinate their immune response, according to researchers from the University of Warwick. The researchers discovered that at dawn, when fungal infections are most likely to occur, their immune system is the highest and isolated a single protein, JAZ6, that drives this time-dependent process.
"Plants are able to predict when pathogen infection is more likely to occur and regulate their immune response to combat this, with plants being more resistant to infection after inoculation at dawn compared to inoculation at night," said Katherine Denby, lead researcher of the study, in a press release.
"The difference in a plant's resistance to infection at different times of the day is driven by its circadian clock rather than daily light/dark changes, with the differences existing regardless of whether you put the plants in constant light for a day and then infect at what would be dawn or night."
The researchers discovered the circadian mechanism by infecting plants with Botrytis cinerea spores every three hours over the period of one day and observed an increased disease resistance in plants what were inoculated in the morning.
"We infected plants with a dysfunctional circadian clock in the morning and at night with our fungal pathogen and observed that the plant no longer had a difference in resistance at the two times of day," said Claire Stoker, co-author of the study. "This pattern showed us that resistance must be driven by the plant's internal clock."
The findings can be used to isolate select parts of the plant immune response in order to control resistance to fungal pathogens and help improve the disease resistance of crops through molecular breeding methods.
The findings were published in the Nov. 21 issue of The Plant Journal.
