Journal of Plant Pathology & Microbiology

Putative xylanaseavtivity of Pseudomonas syringaepv. actinidiae(Psa)

International Conference on Plant Physiology & Pathology

June 09-10, 2016 Dallas, USA

Rasika Subasinghe

University of Waikato, New Zealand

Posters & Accepted Abstracts: J Plant Pathol Microbiol

Abstract:

Actual invasion strategies and mobility of the Pseudomonas syringaepv. actinidiae (Psa) pathogen in the kiwi fruit plant remain inconclusive. Psa, indicated a significant level of xylanase activity especially when the pathogen was cultured on minimal media supplemented with 5% ground kiwifruit tissue. Further studies of in-planta activity of Psa xylanse were conducted with 20 mature Hort 16 A kiwifruit plants; 10 plants uninfected and 10 plants infected with Psa. When disease symptoms appeared in the inoculated plants, both infected and non infected shoots were harvested. Psa was re-isolated from infected plants and duplex PCRs were conducted to confirm that symptoms were due to Psa infection. Remazol Brilliant Blue (RBB) and 3,5-Dinitrosalicylic acid (DNSA) assays were conducted on ground kiwifruit stem pieces to ascertain putative xylanase activity. RBB assay indicated xylanase activity in infected kiwifruit stem pieces and the RBB asssy on non-infected kiwifruit pieces did not indicate xylanase activity. DNSA assays did not produce a detectable xylanase activity in the infected tissues. Therefore, further RBB assays were conducted to ascertain whether the xylanaseactivty in infected tissues was due to enzymatic activity. Strength tests were conducted on infected and non-infected kiwifruit shoots 4 weeks after the innoculation to determine the difference in stength of kiwifruit shoots. The average strength per mm thickness of non-infected kiwifruit xylem was significantly higher than that of infected xylem. Experimental results using Psa-infected kiwi fruit plants clearly indicate a putative xylanase activity and the observed reduction of strength of the kiwifruit xylem is consistant with the presence of a xylanase activity.

Biography :

Email: rs208@students.waikato.ac.nz