. 2010 Oct 25;62(2):717–733. doi: 10.1093/jxb/erq312

Table 2.

Osmotic forces driving root water uptake

Root	Day or night	Osmolality, mosmol kg⁻¹		Driving force (mosmol kg⁻¹) [MPa]
Root	Day or night	Root medium	Exudate	Driving force (mosmol kg⁻¹) [MPa]
Seminal	Day	14±4	49±6^a	(35±10)^a [0.086±0.025]
	Night	17±8	78±24^b	(61±18)^b [0.150±0.044]
Adventitious	Day	14±4	81±7^b,c	(67±7)^b,c [0.164±0.017]
	Night	16±9	60±12^b,d	(44±17)^a,b [0.108±0.042]
Entire root system	Day	17±2	31±3^e	(14±4)^d [0.034±0.010]

The driving force was calculated as the difference in osmolality between root exudate and medium. Exudates were collected as part of exudation experiments; media were collected in parallel. Results are means±SD of seven or eight (day) and four (night period) root analyses.

Statistical significance of difference in exudate osmolality or in driving force between day and night and between types of root analysed is indicated by different superscripts (P≤0.05, Student's t-test).