Figure 1.
Up-regulation of GhGA20ox1 or suppression of GhGA2ox in cotton fibers.
(A) Quantitative RT-PCR analysis of GhGA20ox1 in 5-dpa fibers of T0SCPF::GhGA20ox1 lines (SG20) and the wild-type cotton (WT). (B) Quantitative RT-PCR analysis of GhGA20ox1 in 10-dpa and 20-dpa fibers of SG20-1 (T3generation) and WT. (C) Quantitative RT-PCR analysis of GhGA2ox2 in 5-dpa fibers of T0BAN::GhGA2oxRNAi lines (BG2i) and WT. (D) Quantitative RT-PCR analysis of GhGA2ox2 in 10-dpa and 20-dpa fibers of BG2i-2 (T3generation) and WT. (E) Endogenous GA1 and GA4 content in 8-dpa fibers of SG20-1, BG2i-2 and WT. (F) Endogenous GA1 and GA4 contents in 20-dpa fibers of SG20-1, BG2i-2 and WT.
Figure 2.
Effects of GA overproduction on secondary cell wall deposition in cotton fibers.
(A) Cotton fibers on seeds; bar = 1 cm. (B) Cross-section of mature cotton fibers; Bar = 25 µm. (C) Micronaire values of cotton fibers in 2012 and 2013, n = 6. (D) Cell wall thickness of mature cotton fibers. (E) Weight of 1000 cotton fibers, n = 60. (F)Cellulose contents of mature cotton fibers, n = 6Asterisks (*) and double asterisks (**) represent significant differences(t test) at p = 0.05 and p = 0.01 compared with the wild type, respectively.
Figure 3.
Sucrose synthase expression in GA overproduction cotton fibers.
(A) Quantitative RT-PCR expression analyses of secondary cell wall related genes in 20-dpa fibers. GhCesA1, U58283; GhCesA2, U58284; GhRac13, S79308; GhSusA1, HQ702817; GhADF1, DQ088156 andGhCTL1, AY291285. (B) Sucrose synthase activity in 20-dpa cotton fibers. (C) Sugar contents in 20-dpa cotton fibers, n = 3. Double asterisks (**) represent significant differences (t test) at p = 0.01 compared with the wild type cotton. (D) GhSusA1 expression levels of in vitro cultured fibers treated with GA3 of various concentrations.
Figure 4.
Sucrose synthase expression and cellulose biosynthesis in GA-treated hypocotyls.
Seedlings wereimmersed in distilled water (pH6.0) or GA3 solutions (0.05 mM, 0.1 mM and 0.5 mM, pH6.0).(A) Quantitative RT-PCR analysis of GhSusA1 transcript in hypocotyls. (B) Effects of GA3 treatment on cotton seedling growth. (C) Relative elongation of hypocotyls. (D) Cellulose amount in GA-treated hypocotyls.