Figure S1 - Interaction between <em>Medicago truncatula</em> and <em>Pseudomonas fluorescens</em>: Evaluation of Costs and Benefits across an Elevated Atmospheric CO₂

Description and illustration of a gnotobiotic pot. Gnotobiotic pot (A) made for the experiment allowing the growth of Medicago truncatula in microbiologically controlled conditions because of a glass pot (1) fixed to the cover with a plate (2) during 15 days at the beginning of growth. After this date, glass pot was removed and silicone was disposed around the hypocotyl (B). The plant was watered through a 0.2 µm filter (3). Air circulation is done through two air filters (4,5). The water outlet was controlled manually with a clamp (6). Figures (C) and (D) show more advanced developmental stage, corresponding to 35 days without and with the strain respectively, in CO2 ambient conditions. (DOCX)