Figure Legends

Figure 1. Transcriptional analysis of Arabidopsis seedlings co-cultivated with S. indica. A ) Venn diagram showing the numbers of differentially expressed genes in Arabidopsis plants 2- and 14-days post infection with S. indica compared to control plants that were mock infected. B ) ClueGo analysis of induced DEGs. The figure shows the representative molecular function interaction among the targets. C ) qPCR analysis of transcriptional responses of identified target genes in plants that were co-cultivated for 2 and 14 days, respectively, with S. indica compared to mock treated plants. The data represent means ± SE (n = 3).
Figure 2. Protein-protein interaction (PPI) studies to identify binding partners of CBL7. A ) Yeast cells co-expressing the indicated combinations of constructs were grown on non-selective (-LW) or selective (–LWH) media. Colony growth on the selective media indicated protein–protein interactions. The empty activation domain (AD) vector was used as a negative control. Fivefold diluted cell cultures were inoculated on each spot as indicated by the triangle widths. A representative data set of an experiment replicated three times on different biological samples is shown. BD, binding domain. B ) Interaction network for CBL7 inferred from 58 publicly available datasets included in GeneMANIA v3.5.2. The PPI network indicates the protein set that either directly (diamonds) or indirectly (circles) interact with CBL7 (triangle). The different shape size refers to the calculated interaction score, while the thickness of the edges indicates the normalized maximal weight of the interaction.
Figure 3. Total root network length of Arabidopsis wild-type and mutant plants after 14 days of co-cultivation with S. indica or mock treatment . A ) Comparison of two cipk13 T-DNA insertion mutant alleles with Col-0. B ) Analysis of the fungus-triggered growth promoting effect in Col-3 and cbl7 mutant plants. C ) The growth promoting effect of S. indica is not affected in the hak5 mutant. The box plots show the median, quartiles, and extremes of the compared datasets (n = 24). Asterisks indicate significant differences between S. indica and mock treated samples. Student’s t -test: **P≤0.01, ***P≤0.001.
Figure 4. Analysis of transcriptional differences betweencbl7 mutant and wild-type Col-3 plants. A ) DEGs statistics for the cbl7 mutant compared to Col-3 control plants under control conditions. B ) Volcano plot of the distribution of all DEGs, mapping the 20 upregulated genes (red) and 53 downregulated genes (blue). The figure shows the relation between the significance (-log10(q-value)) and the strength (log2FC) of the differential expression. C ) Bar plot of the KEGG enrichment analysis of induced DEGs in cbl7compared to Col-3 control plants under control conditions. Only the spliceosome KEGG term appeared to contain significantly enriched genes. Gene enrichment is given by -log10(q-value).
Figure 5. K+ contents of root and shoot tissues of S. indica infected and non-infected control plants . The plants were grown in modified Hoagland medium under K+ starvation (0 mM KCl) (A ) or at 1 mM KCl (B ). The box plots show the median, quartiles, and extremes of the compared datasets (n = 15). Different letters indicate significant differences between the compared conditions and genotypes analyzed by ANOVA and a Tukey-Kramer post hoc test (P<0.05).
Figure 6. Transcriptomics analysis of mock and S. indicatreated the cbl7 mutant plants to wild-type Arabidopsis.A ) DEGs statistics for the cbl7 mutant and Col-3 control plants after co-cultivation with S. indica for 14 days.B ) KEGG enrichment analysis of induced DEGs in cbl7co-cultivated with the fungus versus similarly treated Col-3 plants. Each circle in the figure represents a distinct KEGG pathway, and the circle size indicates the number of genes enriched in the corresponding metabolic pathway. The significance of the observed gene enrichment is represented by a color gradient referring to the adjusted p-value (padj). C ) Venn diagram showing the numbers of DEGs in Col-3 and cbl7 14-days post infection with S. indica compared to control plants that were mock infected. D ) Functional network analysis of DEGs in cbl7 and Col-3. Up- and down-regulated genes are differentiated by color and shape. The shape size refers to the different levels of differential expression according to thelog 2FC levels observed in the RNAseq analysis. Functional associations are highlighted in the figure.
Figure 7. Analysis of the colonization of Col-3 and cbl7roots with S. indica . A ) Trypan blue stain of root segments at 1 to 2 cm distance from the root tip. The figure shows representative pictures for the three studied genotypes after 14 days of co-cultivation with S. indica. B) Quantitative assessment of root colonization by qPCR analysis of SiTEF1 . Depicted are means ± SE of three independent biological experiments performed in triplicate. The Arabidopsis GAPC2 gene served as endogenous control. Asterisks indicate significant differences (Student’s t -test: ***P≤0.001).