Table 1.
Effect of different antibiotics on the in vitro growth of D. sansibarensis and removal of its bacterial symbiont O. dioscoreae.
Table 2.
Efficiency comparison between node cutting sterilization protocols.
Fig 1.
Phenotypic differences between symbiotic (left) and aposymbiotic (right) D. sansibarensis.
A. Plants inoculated with O. dioscoreae or B. with a mock solution. C. Cross-section of D. sansibarensis gland stained with acridine red, chrysoidine and astra blue showing a dense, orange-colored mixture of mucus and bacteria filling the lumen of symbiotic glands, and D. glands of aposymbiotic plants; E. Adaxial side of leaves of symbiotic; F. aposymbiotic plants kept in gnotobiotic conditions. G. SEM cross-section of symbiotic and H. of aposymbiotic acumen. I. SEM detail picture of trichome cells in the acumen being colonized by bacteria or J. aposymbiotic. K. TEM of trichomes in the acumen, surrounded by bacteria in symbiotic glands or L. deteriorating in aposymbiotic glands. M. Close-ups TEM showing the endoplasmic reticulum, Golgi, and plastids in the trichomes; and N. being mostly empty and containing plastids.
Fig 2.
Fluorescence microscopy of the symbiotic gland at the acumen A. Overview of a TBO–stained transverse section viewed under brightfield, showing one gland in the leaf drip-tip. B. Close-up of a D. sansibarensis leaf gland colonized by mCherry-tagged bacteria (R-71417). C. Close up showing bacteria (B) surrounding the trichomes (T).
Fig 3.
Macroscopic phenotypes of aposymbiotic and symbiotic D. sansibarensis.
A. Daily mean chlorophyll content of individual plants tracked over a period of 30 days post inoculation estimated through RGB values of plant images. Trajectories of aposymbiotic plants are shown in yellow, symbiotic plants in green and plants with unknown status (see text for details) in blue. Solid lines depict the moving average per condition. Statistical testing was done with non-parametric Kruskal-Wallis tests, grouping samples by date (p-value for each test > 0.05). B. Total leaf area of individual plants tracked over a period of 30 days post inoculation. Color scheme is the same as above. Statistical testing was done as above (Kruskal-Wallis p > 0.05) C. Stem length (in cm) of plants measured at the end of the experiment. Data from aposymbiotic plants are shown in yellow, symbiotic plants in green and plants of unknown status in blue (see main text for details). Black dots are values randomly scattered around a central axis to improve readability. Large black dots in the “Unknown status” category represent distribution outliers. The distributions of values between the 3 categories of plants are identical for each of the 3 parameters (Kruskal-Wallis test p > 0.05).