Figure 1.
AtRD22 and AtUSPL1, members of the BURP gene family.
A. Scheme of BURP-domain containing proteins AtRD22 and AtUSPL1. BURP (named after BNM2, USP, RD22 and Polygalacturonase isozyme) proteins are identified by their C-terminal BURP-domain (red). The BURP domains contain 4 CH-repeats (black). In comparison to AtUSPL1, AtRD22 contains an additional motif, the TXV repeats (yellow), in AtUSPL1 no repetitive domain structure can be found. AGI ID is given in brackets. Position of T-DNA insertions for the used loss-of function mutants is indicated by a green arrow. B. Quantification of AtRD22 and AtUSPL1 mRNA in leaves and roots. The bar diagram indicates the amplification of AtRD22 (left) and AtUSPL1 mRNA relative to ACT2 mRNA (amp. rel. to ACT2 mRNA). Leaf (green) and root (brown) tissue of well watered and drought stressed (2% RWC) plants (N = 5) was analyzed. Asterisks indicate significant differences (T-test: *** p<0.01, ** = p<0.05).
Figure 2.
Histochemical ProAtUSPL1::GUS activity in transgenic Arabidopsis plants.
The AtUSPL1 promoter activity was determined by histochemical localisation of GUS activity derived from the transgenic ProATUSPL1::GUS reporter gene. Activity indicated by blue colour can be seen in A) seedling; B) in funiculus of mature seeds; C) in flowers and stems; and D) in roots.
Figure 3.
Influence of drought stress treatment on single and double loss of function mutants.
A) Four weeks old wild type (Col-0), single and double mutant plants (rd22-1 and uspl1, rd22-1/uspl1) were drought stressed for 1–5 days before they were returned to climate chamber conditions. Time of stress treatment in days is indicated left. B) Growth rates of plants under control and drought stress conditions. Bars indicate the growth rates at 22 days after sowing (DAS) for early phase of drought stress and 34 for the late phase of drought stress. For application of drought stress stop of watering started at 21 DAS. Wild type (Col-0): green bar; rd22-1: bright blue bar; rd22-2: dark blue bar; uspl1: purple bar; rd22-1/uspl1pink bar. Original data: Figure S5 B, Table S2, Asterisks indicate significant differences (p<0.01). C) NIR reflection as a water content-related parameter. Bars indicate the NIR intensity at 21 days after sowing (DAS) for start of experiment and at 35 DAS for the end of experiment. Wild type (Col-0): green bar; rd22-1: bright blue bar; rd22-2: dark blue bar; uspl1: purple bar; rd22-1/uspl1pink bar. Ncontrol = 5, Nstress = 10 plants. Original data in Table S3.
Figure 4.
Chlorophyll and pheophytin content in single and double BURP mutants.
The bars represent the total A) chlorophyll and B) pheophytin content in leaves from wild type (Col-0, green bar), single and double mutant plants (rd22-1, red bar, uspl1, blue bar and rd22-1/uspl1, grey bar). Chlorophyll a and b was determined separately (Figure S6A) and subsumed as total chlorophyll content. Error bar represents standard error. N = 5–6 plants in duplicate. Statistical analysis was performed by oneway ANOVA at alpa = 0.05 Tukey post hoc test: same letters indicate no difference, different letters indicate significant difference. C) The bars show the total chlorophyll content [%] relative to unstressed control plants.
Table 1.
Top differential expressed genes in A) rd22-1 and B) uspl1 at standard growth conditions in the aerial part of 2 week old seedlings.
Table 2.
Differential expressed genes in A) rd22-1 and B) uspl1 on medium containing 150mM NaCl in the aerial part of 2 week old seedlings.