Figure 4.

Expression analysis of all potato SWEETs in roots in response to colonization by the Arbuscular mycorrhizal fungus R. irregularis. (A) The expression of the phosphate transporter PT4 and the cell wall-bound invertase InvCD141 from potato, as well as the fungal translation elongation factor 1a RiTEF and the monosaccharide transporter gene RiMST2 were analyzed at 4, 6, and 8 weeks post inoculation (wpi). (B) Expression of potato SWEETs was measured at 6 and 8wpi. Expression is shown as relative expression to potato elongation factor 1α (Stef1) or to RiTEF for RiMST2. Error bars represent standard error of the mean. Non colonized samples are indicated by minus (−) and colonized samples by plus (+), per treatment the average expression of three biological replicates is shown. Student's t-test was used to calculate significance of mycorrhized compared to non mycorrhized samples in the same time point (^**p < 0.01, ^*p < 0.05).