Cell-penetration and translocation of
CPPs in leaves after spraying.
(a) Leaf cell architecture and possible uptake mechanisms of CPP into
different leaf cell layers after spraying. (b–e) Retention
and translocation of different tetramethylrhodamine (TAMRA)-labeled
CPPs into the upper epidermal cells (b, c) and palisade mesophyll
cells (d, e) of Arabidopsis thaliana leaves at various
time points after spraying. Two independent experiments (two leaves
per experiment) were performed for each TAMRA-CPPs and two regions
of interest (ROIs) in one leaf were observed by CLSM. The average
fluorescence intensities of 8 ROIs (n = 8) in leaves
at different time points after spraying are shown as heat maps for
upper epidermal cells (b) and palisade mesophyll cells (d). The distributions
of TAMRA fluorescence signals in plant cells were presented in Figure S2. Colored bars represent the range of
fluorescence intensity in the heat map in arbitrary units (A.U.).
(c, e) Scale bars = 50 μm. (f) Plant characteristics of three
commercially important soybean cultivars (5 weeks old). Scale bar
= 15 cm. (g) TAMRA fluorescence intensities in epidermal cells in
soybean leaves at different time points after spraying with TAMRA-labeled
CPPs. The distribution of TAMRA fluorescence in plant cells is presented
as a box plot from 8 different regions of interest (2 ROIs per leaf,
2 leaves per experiment, 2 independent experiments, n = 8). Black bars show the median values.