(A) Immunoblot analysis between native ACE2(N) and codon
optimized ACE2(co). The bottom graph visualizes the mean ± SD of
normalized ACE2 intensities to RbcL (loading controls) (bottom). **P-value
< 0.01 vs. Native. PH, tobacco Petit Havana; LS, lettuce; WT,
untransformed wild type; N, native sequence; CO, codon-optimized sequence.
(C) Western blot of CTB-Ang-(1–7) T0 generation. Lanes
#1 to 6, individual plant. (D) Western blot of CTB-Ang-(1–7)
in equal amount of fresh and lyophilized plant cells (1X). (C-D)
WT, untransformed wild type lettuce, M, protein standard; CTB, cholera non-toxic
B subunit; Lyo, lyophilized lettuce. RbcL was used as loading controls. GM1
ELISA assay of (B) CTB-ACE2 and (E)
CTB-Ang-(1–7) pentamer. WT, untransformed wild type; Lyo, lyophilized
lettuce. Data are expressed as the mean ± SD. ***P-value < 0.001
vs. WT. The data obtained from two independent biological repeats run in
triplicates. (F) Western blot analysis of ACE2 accumulation in
transplastomic lettuce plants harvested from Fraunhofer hydroponically (FH) and
Greenhouse (GH) with different times (F and G). Western blot was
performed for different ages ranged from 46 days and 66 days for FH and 46 days
for GH (F), 82 days and 106 days for FH and 60 days for GH
(G); The amount of TP loaded is given above the respective lane
in g. The arrows indicate the 100 kDa Ace2. M: spectra multicolour broad range
protein ladder (Thermo Scientific, molecular weight of the marker bands
indicated in kDa). (H) Determination of fresh weight, dry weight,
ACE2 expression, and ACE2 yield per plant with different ages between Greenhouse
and Fraunhofer. Plant ages are relative to the date of germination. Fresh and
dry weight per plant are calculated by normalization of total fresh and dry
weight to total number of plants grown in Greenhouse (16) and Fraunhofer (400).
The percentage of water content (the ratio of dry material / fresh material) are
shown on the top of column. (I) Stability of CTB-ACE2 after
long-term storage. #1 to #3, individual lettuce CTB-ACE2(co) transplastomic
lines. Data are expressed as the mean ± SD.