Atomic Force Microscopy: A Tool for Studying Biophysical Surface Properties Underpinning Fungal Interactions with Plants and Substrates

Abstract

One of the primary roles of the cell surface is to provide an effective barrier to various external environmental factors. Specifically, the surface properties of organisms serve as a critical obstacle to pathogen attack. Since its inception, Atomic Force Microscopy (AFM) has enabled nanoscale imaging of cell surfaces in their native state. However AFM has yet to be systematically applied toward resolving surface features and the forces underpinning plant-fungal interactions. In an effort to understand the physical forces involved at the plant-microbe interface, we describe a method for the attachment of fungal spores to AFM tips and the subsequent measurement of unbinding forces between spores with a range of substrates and plant surfaces under physiologically relevant conditions. Investigations of binding events using AFM offer an unexplored, sensitive, and quantitative method for analyzing host-pathogen/microbe-surface interactions.

Friends or foes? Emerging insights from fungal interactions with plants

“…Atomic force microscopy (AFM; Binnig, Quate and Gerber 1986), another surface scanning method, images live biological specimens under ambient conditions at higher resolution than cryo-SEM (Dahms and Kaminskyj 2008). AFM in force mapping or quantitative imaging mode gives additional information on mechanical and molecular surface properties of the sample, appropriate for probing cell spring constants, cell wall elasticity and specific molecular surface interactions between plants and their pathogens, for instance interaction forces between spores and plant surfaces in the context of host invasion (Adams et al 2012).…”

Experimental approaches to study plant cell walls during plant-microbe interactions

“…AFM has recently been used to detect the interaction of a synthetic carbohydrate-binding module with plant cellulose, and the structural changes of crystalline cellulose at a cell-wall surface (Zhang et al, 2012 , 2013 ). In terms of plant microbe interactions, AFM recently provided nanoscale imaging of cell surfaces in their native state and revealed cell wall dynamics and modification during Arabidopsis and Fusarium oxysporum interaction (Adams et al, 2012 ). These selected studies underline the necessity to utilize the ever-expanding technological advances in imaging systems, often in concert with metabolic profiling, to maximize the detail of the investigation.…”