Kahandawa Geeganaarachchige Ariyawansa

Doctor of Philosophy, (Genetics)
Study Completed: 2016
College of Sciences

Citation

Thesis Title
Sensing and signalling mechanical stress during intercalary growth in Epichloë grass endophytes

Read article at Massey Research Online: MRO icon

Until recently, the filamentous structures (hyphae) of fungi were believed to grow solely at the tip. Uniquely a beneficial fungus (Epichloë festucae) of temperate grasses, is able to grow at the tip as well as along the length of the filament (intercalary growth) when colonising growing leaves. Mr Ariyawansa hypothesised that the fungus can sense mechanical stress caused by changes in plant development, and respond by switching growth from the tip to the rest of the filament. To test this he developed a mechanism to stretch fungal hyphae and proved that mechanical stress stimulates intercalary growth. By deleting potential stress sensors he demonstrated that calcium influx is required for growth of E. festucae in grass leaves. The investigation revealed that mechanical stress and Ca influx through mechano-sensitive calcium channels may play pivotal signalling roles, providing a plausible explanation for how intercalary growth occurs in E. festucae.

Supervisors
Professor Rosie Bradshaw
Dr Christine Voisey