Figure legends
Figure 1. Sowing depth significantly affects both tomato seed
germination and hypocotyl elongation. (A) Morphology of 10-day tomato
cultivar ‘Heinz 1706’ seedlings after seeds were sown at different depth
of soil. Dotted lines crossing the pots indicated the positions of
seeds. Scale bar, 1cm. (B) Percentage of tomato seedlings emerged from
soil. (C) Germination rate of tomato seeds at day 5 after sowing. (D)
Morphology of 7-day tomato seedlings after sown at 4 cm depth of soil.
Data are presented by means ± SE. Different letters indicate statistical
significance (p < 0.05) determined by LSD Test in DPS
Software.
Figure 2. Interactions between
SlUVI4 and SlCCS52 proteins. (A) Yeast-two hybrid assay. Serial
dilutions of yeast cells
containing SlUVI4 fused with the activation domain (AD) and SlCCS52
fused with the DNA binding domain (BD) were plated on amino acid
deficient yeast growth medium. (B) Confocal microscopy images from BiFC
assay in onion epidermal cells. SlUVI4:YFPN together
with SlCCS52A1:YFPC or
SlCCS52A2:YFPC were transiently expressed in onion
epidermal cells. Images were taken at 48 h after incubation. Green
signals are from YFP. Scale bar, 50 μm.
Figure 3. Gene expression of SlUVI4 and SlCCS52s in
different tissues and hypocotyls at different growth stages. The
transcript abundance of SlUVI4 (A), SlCCS52A1 (B),SlCCS52A2 (C) and SlCCS52B (D) in different tissues of
tomato cultivar ‘Heinz 1706’ and hypocotyls at day 1, 3, 5 and 7 after
seed germination (1d, 3d, 5d, 7d) were analyzed by quantitative reverse
transcription polymerase chain reaction (qRT-PCR). SlCBL1(Calcineurin B-like protein, Solyc12g015870) transcript abundance was
used for data normalization. The transcript abundance of each gene in
the root was used for all comparisons to calculate the relative
expression. Data shown are means ± SE calculated from three independent
experiments. Letters on the top of each column indicate statistically
significant differences (p < 0.05) determined by LSD
test in DPS software.
Figure 4. Different lights have distinct impacts on hypocotyl elongation
and gene expression of SlUVI4 and SlCCS52s . Tomato
seedlings of cultivar ‘Heinz 1706’ were grown on MS medium under red
light (A-D) and blue light (E-H) conditions. (A, E) Morphology of tomato
seedlings. (B, F) Hypocotyl length. (C, G) Diameter in the middle of
hypocotyl. Data represents means ± SE (n > 15). Different
letters indicate statistical significance (p < 0.05)
determined by LSD test in DPS Software. (D, H) Nuclear DNA distribution
in hypocotyls. Data are presented by means ± SD. EI values are on the
top of columns. (I) qRT-PCR analysis of SlUVI4 , SlCCS52B ,SlCCS52A1 and SlCCS52A2 in hypocotyls using SlCBL1as a reference gene. Data shown are means ± SE calculated from three
independent experiments.
Figure 5. MS salts and sugar enhance hypocotyl elongation through the
promotion of SlUVI4 and SlCCS52B transcription. Tomato
seedlings were grown on non-MS agar (NMS, A-D), MS agar (MS, E-H) and MS
agar with sugar (MSS, I-L) for 1, 3, 5, and 7 days after seeds were
sown. (A, E, I) Morphology of tomato seedlings. (B, F, J) Hypocotyl
length. (C, G, K) Diameter in the middle of hypocotyl. Data represents
means ± SE. Different letters indicate statistical significance
(p < 0.05) determined by LSD test in DPS Software. (D,
H, L) Nuclear DNA ploidy distribution in hypocotyls. Data represents
means ± SD. The number on the top of each column indicates EI. (M)
qRT-PCR analysis of SlUVI4 ,SlCCS52B , SlCCS52A1 , and SlCCS52A2 in hypocotyls
using SlCBL1 as a reference gene. Data shown are means ± SE
calculated from three independent experiments. Letters on the top of
each column indicate statistically significant differences (p< 0.05) determined by LSD test in DPS software.
Figure 6. Heat enhances hypocotyl elongation through the
transcriptional modulationSlUVI4 and SlCCS52 genes. (A) Morphology of day seedlings
grown on NMS and MS agar plates at 25°C and 33°C. (B) Hypocotyl length.
(C) Diameter in the middle of hypocotyl. (D) Nuclear DNA ploidy
distribution in hypocotyls. (E) qRT-PCR analysis of SlUVI4 ,SlCCS52B , SlCCS52A1 and SlCCS52A2 in hypocotyls
using SlCBL1 as a reference gene. The transcript abundance
of each gene at 25°C was used to calculate the relative expression. Data
shown are means ± SE calculated from three independent experiments. The
asterisk on the top of column indicates statistically significant
differences (p < 0.05) determined by studentt -test.
Figure 7. Auxin promotes the hypocotyl elongation via the
transcriptional modulation of SlUVI4 and SlCCS52 genes.
(A) Morphology of tomato cultivar ‘Heinz 1706’ seedlings after 0.1 nM
IAA treatment for 7 days. (B) Hypocotyl length. (C) Diameter in the
middle of hypocotyl. (D) Nuclear DNA ploidy distribution in hypocotyls.
(E) qRT-PCR analysis of SlUVI4 and SlCCS52s in hypocotyls
using SlCBL1 as a reference gene. Data shown are means ± SE
calculated from two independent experiments. The asterisk on the top of
column indicates statistically significant differences (p< 0.05) determined by student t -test.
Figure 8. Salt stress inhibits hypocotyl elongation through the
transcriptional modulation of SlUVI4 and SlCCS52 genes.
(A) Morphology of tomato cultivar ‘Heinz 1706’ seedlings after 150 mM
NaCl treatment for 7 days. (B) Hypocotyl length. (C) Diameter in the
middle of hypocotyl. (D) Nuclear DNA ploidy distribution in hypocotyls.
(E) qRT-PCR analysis of SlUVI4 and SlCCS52B in hypocotyls
using SlCBL1 as a reference gene. Data shown are means ± SE
calculated from three independent experiments. The asterisk on the top
of column indicates statistically significant differences (p< 0.05) determined by student t -test.
Figure 9. Ethylene affects the hypocotyl elongation via the
transcriptional modulation of SlUVI4 and SlCCS52 genes.
(A) Morphology of tomato cultivar ‘Heinz 1706’ seedlings after 10μM ACC
treatment for 7 days. (B) Hypocotyl length. (C) Diameter in the middle
of hypocotyl. (D) Nuclear DNA ploidy distribution in hypocotyls. (E)
qRT-PCR analysis of SlUVI4and SlCCS52B in hypocotyls using SlCBL1 as a reference
gene. Data shown are means ± SE calculated from three independent
experiments. The asterisk on the top of column indicates statistically
significant differences (p < 0.05) determined by
student t -test.
Figure 10. Deletion mutants of SlUVI4 exhibit defective hypocotyl
elongation. (A) Morphology of 7-day seedlings grown on MS medium. (B)
Hypocotyl length. (C) Diameter in the middle of hypocotyl. Data
represents means ± SE (n > 19). Different letters indicate
statistical significance (p < 0.05) determined by LSD
test in DPS Software. (D) Nuclear DNA ploidy distribution in hypocotyls.
Data are presented by means ± SD. EI values are on the top of columns.
Figure 11. Overexpression of SlCCS52B suppresses hypocotyl
elongation. (A) Morphology of 6-day seedlings grown on 1/2 MS medium
under 10μmol m−2 s−1 light. (B)
Hypocotyl length. Data represents means ± SE (n > 50).
Different letters indicate statistical significance (p< 0.05) determined by LSD test in DPS Software. (c) Nuclear
DNA ploidy distribution in hypocotyls. Data are presented by means ± SD.
EI values are on the top of columns.