plant surface microbiology.pdf

27 Applications of Quantitative Microscopy in Plant Surface Microbiology 533
neer microflora that develop on the white clover seedling rhizoplane during
their first 2 days of growth in soil, and (4) the spatial scale of quorum sensing
of signal molecules by rhizobacteria colonized on the root surface.
6.3 CMEIAS v. 3.0: Plotless and Plot-Based Spatial Distribution Analysis
of Root Colonization
For this first example, CMEIAS image analysis was performed on a scanning
electron micrograph of a region of the white clover seedling root surface colonized
by cells of Rhizobium leguminosarum bv. trifolii wild-type strain
ANU843 to extract many different types of quantitative data relevant to plant
surface microbiology (Fig. 10A). Figure 10B illustrates the frequency distribution
of their first and second nearest neighbor distances (distance between
object centroids), as two examples of their spatial distribution in a plot-less
analysis. Table 1 lists 15 quantitative features relevant to plant surface micro-
Fig. 10. Colonization
of the white clover
root surface by wildtype
R. leguminosarum
bv. trifolii ANU843 in
gnotobiotic culture.
A Scanning electron
micrograph of a region
of the root surface colonized
by the bacteria.
Bar scale 1 mm.
B CMEIAS plot-less
spatial distribution
analysis of bacterial
cells in (A) measured
as the frequency distribution
of each cell’s
first and second nearest
neighbor distance