Fig. 1: Microcosm design and sampling strategy.
From: Community RNA-Seq: multi-kingdom responses to living versus decaying roots in soil
A Microcosms had a main chamber that housed the plant, Avena fatua, during plant growth and maturation. The main chamber was separated from an auxiliary root chamber (the sidecar) by a solid divider; microcosms were tilted to promote root growth along the outside face of the sidecar. After 6 weeks, the solid divider was removed and replaced with a slotted divider to permit root growth into the sidecar, and the sidecar was then filled with experimental soil. B Litter-containing microcosms (rhizosphere-litter, bulk-litter) were amended with 15N-labeled root detritus (Layer 2), which was placed on top of unamended soil (Layer 1). Unamended microcosms (rhizosphere-control, bulk-control) were prepared in the same manner, but no litter was added to Layer 2. After 6 days the roots entered the sidecar, and the plants were then pulse labeled for 3 days with 13CO2 and harvested. Rhizosphere soil (<2 mm from a root growing along the face of the sidecar) and bulk soil (>4 mm from root) were excised with a scalpel.
