For scanning electron microscopy, the flag leaves of WT and
PSARK::IPT plants under WW and WS were sampled and immediately
fixed in an aqueous solution containing 2.5% glutaraldehyde
and 4% paraformaldehyde in 0.05 M cacodylate buffer
(pH 7.2) for 2 h. Samples were post-fixed with 1% OsO4 in the
sample buffer during 1 h after the samples were dehydrated.
Ultrathin sections (70 nm) of the parenchyma rice cells were
obtained using a Reichert Ultracut ultramicrotome stained with
uranyl acetate followed by lead citrate. The samples were
observed with a Philips CM120 Biotwin lens transmission electorn
microscope (FEI, Hillsboro, OR, USA).