Understanding Cuticle Morphology Differences Between WT and TG (AVP1) Creeping Bentgrass Using Fractal Analysis.

Plant cuticles have gained much attention over the past decade.  Of particular interests are the micro- and nano- structures that are produced on the surface and provide protection from various environmental effects to the plant.  Many of the classification and terminology utilized to describe this shapes are difficult to determine small differences in crystalloid shape.  Fractal analysis has been employed in research to study the shapes and surface roughness of objects.  The fractal analysis can be used to determine mathematically that certain objects that appear to the eye different are statistically dissimilar.  In the present study, fractal analysis was utilized to determine if the crystalloid shape of WT and TG creeping bentgrass cuticles were different and investigate possible causes of this occurrence.  WT and TG crystalloid shapes had fractal dimension (Df) means of 1.51 and 1.23, respectively (p < 0.001).  This data confirms that crystalloid shape was indeed statistically different, although similar in structure.  Crystalloid shape is dependent on chemical composition, and the data suggest the plant is altering the chemical composition of the TG cuticle to produce the desired crystalloid shape.  This study provides insight into the cuticle’s crystalloids protection mechanism as well as, utilizing the fractal dimension for statistically testing various crystalloid shapes.