Seeking to uncover the responses of root hydraulics and water uptake to transpirational water loss, Meng et al. analyse three-week old rice plants, observing changes in root aquaporin expression and hydraulic conductivity (Lp) in response to shoot removal.
A rapid decrease (5-60 min) in gene expression (qPCR) of root plasma membrane intrinsic aquaporin proteins (PIPs) is shown to result from shoot removal in rice. Lp decreased in parallel. Application of tension, using a vacuum pump, to detached root systems prevented the decrease in aquaporin expression. The study concludes that xylem tension produces a signal which coordinates and connects root and shoot hydraulics.
This paper is part of the Root Biology Special Issue.