Figure 2

L. camara endophytes colonized S. nigrum endosphere and promoted plant growth. (A,B) One week old S. nigrum seedlings were infected with LacZ-labeled endophytes and stained with 100 µg/mL X-gal. Stained regions of plants are shown with arrows indicating colonization. LC1.:Enterobacter sp. LC1, LC2.:Kocuria sp. LC2, LC3.:Kocuria sp. LC3, LC4.:Enterobacter sp. LC4, LC5.:Kocuria sp. LC5, LC6.:Enterobacter sp. LC6, LC7.:Kosakonia sp. LC7. U: uninoculated control plant, Scale bar = 0.5 cm. Infected roots were visualized under a light microscope. Kocuria sp. LC2 colonization in root sections has been shown. Scale bar = 300 µm. Bacterial chains have been shown in arrowheads (B). (C-G) One week old S. nigrum plants were treated with 25 ppm Na₃AsO₄ or 1 × MS in presence or absence of the endophytes added individually or as a consortium. The biomass (C), root length (D), shoot length (E), leaf number (F) and leaf area (G) were determined 4wpi; n = 12. Data are represented as mean ± SEM. Bars with different letters indicate significant differences amongst different endophytic isolates at a particular As-level (bold italics for +As) obtained from two-way ANOVA with Tukey’s post-hoc test. Significant differences for an individual isolate between −As and +As treatments have been marked by *P < 0.05, **P < 0.01 ***(P < 0.001); ns = no significance. (Df for As:1, for endophytes:8, for interaction:8, error:198).