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.
Delong Meng, Marc Walsh, Wieland Fricke, 2016, 'Rapid changes in root hydraulic conductivity and aquaporin expression in rice (Oryza sativaL.) in response to shoot removal – xylem tension as a possible signal', Annals of Botany, vol. 118, no. 4, pp. 809-819 http://dx.doi.org/10.1093/aob/mcw150