Malays. Appl. Biol. (2017) 46(2): 49-58
MICROSCOPIC OBSERVATION OF A ROOT-ADHERING FACTOR
Avin_16040 IN Azotobacter vinelandii AND Escherichia coli
DURING ASSOCIATION WITH RICE ROOT
LIEW, PAULINE WOAN YING1*, JONG, BOR CHYAN1 and NAJIMUDIN, NAZALAN2
1Agrotechnology and Bioscience Division, Malaysian Nuclear Agency (Nuclear Malaysia),
Bangi, 43000 Kajang, Selangor, Malaysia
2School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Accepted 31 March 2017, Published online 27 June 2017
ABSTRACT
Microbial adherence to plant root is the initial step in a beneficial plant-microbe interaction. Quantitative RT-PCR analysis deduced the Avin_16040 gene showed upregulated expression when Azotobacter vinelandii was adhered to the rice root. By transforming the full-length Avin_16040 gene into a heterologous host Escherichia coli, the recombinant clones displayed filamentous cell shapes in contrast to the rod-shape of wild type cells. Besides full-length gene insert, some E. coli clones were detected to contain truncated Avin_16040 gene inserts but still shape-shifted to filamentous cells. Further analysis by DNA sequencing revealed the shape-shifting E. coli clones contained 3’-end truncated Avin_16040 gene, while E. coli clones containing the 5’-end truncated Avin_16040 gene remained rod-shaped. The cell surface topographies of A. vinelandii and E. coli cells in the presence and absence of Avin_16040 gene and in association with rice root adherence were analysed using atomic force microscopy.
Key words: Avin_16040, Azotobacter vinelandii, Escherichia coli, AFM
