The open reading frame of GeSUT4 cDNA was transferred from
pDONR221-f1- GeSUT4 vector to the binary plasmid vector pMDC32 using the
LR Gateway technology (Curtis & Grossniklaus 2003). Arabidopsis plants
were then transformed with the resulting construct pMDC32-GeSUT4 and
four independent homozygous lines were selected as described previously
(Guo et al. 2014).Bacillus subtilis colonization assayBacillus subtilis strain 168 harboring a GFP reporter (pAD43-25)
(Dunn & Handelsman, 1999) was used for the modified root colonization
assays (Allard-Massicotte et al. 2016). In brief, an overnight
bacterial culture was inoculated into fresh medium and grown for 3 h to
an OD600 of 0.8. Cells were collected and re-suspended at an OD600 of
0.02 in MSNg inoculation medium (4.3 g of MS, 0.05% of glycerol and 10
µg ml-1 of chloramphenicol in 1liter). 7-d-old Arabidopsis seedlings
were harvested, washed with sterile water and transferred to a 24-well
plate containing 500 µl of the Bacillus solution. After 4 h of
incubation, Arabidopsis seedlings were washed with sterilized water and
roots were cut off, photographed, and transferred to 1.5 ml Eppondorf
tubes containing 1 ml of 0.2% NaCl. Bacillus cells were detached by
sonication. Serial dilutions were performed to determine the number of
colony-forming unit (CFU) per cm of root.