HCl (1M) + - + +temp 20 70 70 100° CDPBA - + + +

HCl 1M 1M 1M 2M 2M 2M 2Mtemp 20 60 70 70 80 80 100° Cmin 30 30 30 30 30 60 60

AA BB

CC

Q

0M 1M 2M 2M 20 70 80 100° C 30 60 60 60

K

4m

R

Figure S1. Test of conditions for deglycosylaton of rutin and Brassica anther flavonoids.

Panels A and B show TLC separations of flavonoids after rutin (quercetin-3-rhamnose-glucose) or a

stage-5 Brassica anther extract, respectively, was deglycosylated in 0-2 M HCl at different

temperatures for 30 or 60 min. The TLC plates after DPBA staining were placed on top of a UV

irradiation source and photographed. Q, K and R denote quercetin, kaempferol and rutin,

respectively. Released quercertin and kaempferol fluoresced, whereas unreacted rutin and

glycosylated flavonoids at the origin of the TLC plates did not. Panel C shows CLSM images of

stage-5 Brassica tapetum cells after different conditions of acid deglycosylation and DPBA staining.

Fluorescence is shown in green, and the cell circumference is marked with a dotted white line. All

images in Panel C were taken with identical CLSM settings (laser power and detection gain). The

fluorescent particles in the 100 0C-treated cell had surface extensions (arrowed) that were absent in

those in the 70 0C-treated cell.