Table 1.
PGP traits of isolated bacteria across different Classes.
Fig 1.
Effects of bacterial strains on Arabidopsis root architecture.
a-c) supervised model based clustering performed on the variables a) length b) diameter and c) area of the roots. d) Arabidopsis plantlet phenotypes (after two weeks of growing) grouped in different clusters obtained from “model based cluster” analysis in comparison with non-inoculated (control) and 50nM IAA-treated seedlings. Scale bars: 1 cm.
Fig 2.
Representative Arabidopsis root hairs distribution.
The morphology on maturation zone is compared among the six clusters to a) non-inoculated roots and e) 50 nM IAA-treated seedlings. b) seedling roots grouped in cluster 1 and 2, c) seedling roots grouped in cluster 3–4; d) seedling roots grouped in clusters 5 and 6. Scale bars: 500 μm.
Table 2.
Percentage of strains, for each of the six clusters of recorded plant root response types, that display the tested PGP traits.
Fig 3.
IAA producing bacterial strain effects on Arabidopsis roots.
a-e) histochemical analysis of 8 day-after-inoculation (dai) Arabidopsis DR5::GUS reporter plantlets. A strong induction of β-glucuronidase activity (blue staining) is appreciable in all treated samples (c-e) and in the IAA-treated seedlings (IAA 50 nM, b) compared to non-inoculated seedlings (a). f) 4MU-fluorimetric assay on total protein extract of 8-dai Arabidopsis seedlings highlighted a strong induction of β-glucuronidase activity both in the whole IAA and GL83 treated-plantlets. Data were normalized on non-treated seedlings (CTRL) and reported as percentage of the CTRL. Statistically significant at *, P< 0.01.
Table 3.
Assayed PGP traits of selected strain, their cluster attribution and their taxonomical identification.