Supplemental Figures Clades RSH1 TP - HYD TGS ACT Rsh1[HS] RSH2 TP HYD SYN TGS Rsh2[HS] RSH3 TP HYD SYN TGS CRSH TP - SYN EFh Rsh4[HS] Supplemental Figure 1. Arabidopsis RSH domain structure. Schematic representation of the domain structure of the Arabidopsis RSH enzymes, adapted from Atkinson et al., 211. Membership of RSH gene clades is indicated to the right using the nomenclature of Atkinson et al., 211. TP, chloroplast target peptide; HYD, ppgpp hydrolase domain; SYN, ppgpp synthase domain; TGS, TGS regulatory domain; ACT, ACT regulatory domain; EFh, calcium binding EF hand. RSH1 has a serine substitution in the ppgpp synthase domain that abolishes ppgpp synthase activity and the hydrolase domain of CRSH is degraded and may not be functional (Mizusawa et al., 28, Atkinson et al., 211). 1
A rela spot Vector RSH3 RSH3-GFP RSH3 B rela Vector RSH2 RSH2-GFP RSH2 Supplemental Figure 2. Complementation of ppgpp deficient E. coli mutants by the expression of RSH2 and RSH3 GFP fusion proteins. (A) Expression of the mature form of RSH3 or an RSH3 GFP fusion complemented the growth of a ppgpp null ( rela spot) mutant on minimal media without amino acids. Mutation of the ppgpp synthase active site abolished complementation (RSH3). Bacteria containing the active RSH2 expression constructs could not be recovered in the ppgpp null mutant, as previously described (Mizusawa et al., 28). Therefore RSH2 was tested in a ppgpp deficient rela mutant ( rela) on SMG medium (B). Expression of the mature form of RSH2 and an RSH2 GFP fusion complemented rela, and mutation of the ppgpp synthase active site abolished complementation (RSH2). In both cases the same GFP fusions were used as those in the OX:RSH2-GFP and OX:RSH3-GFP plant lines. 2
A OX:RSH2 GFP 2.2 2.1 2.3 B OX:RSH2 GFP 2.2 2.1 2.3 F 3.1 3.2 3.1 3.2 C OX:RSH3 GFP D OX:RSH3 GFP.1 OX:RSH2 GFP OX:RSH3 GFP.8 αgfp PR 2.1 2.2 2.3 3.1 3.2 RBCL seed area, mm 2.6.4.2 RBCS OX:RSH2 GFP.1 OX:RSH3 GFP.1 OX:RSH3 GFP.2 Supplemental Figure 3. Phenotypes of different RSH2-GFP and RSH3-GFP overexpression lines. Wildtype seedlings and different RSH2-GFP (OX:RSH2 GFP ) and RSH3-GFP (OX:RSH3 GFP ) overexpression lines were grown in plates for 12 DAS and (A) photographed and (B) imaged for chlorophyll fluorescence. F false color scale bar, 5-35 arbitrary units. (C) Immunoblots on equal quantities of total protein extracted from the same seedlings showed that the RSH-GFP fusion protein could be detected in the lines that were small and pale, had a high F, and a low PSII maximum quantum yield QY. Proteins were also revealed by Ponceau Red (PR). (D) Lines overexpressing RSH2-GFP and RSH3-GFP produced smaller seeds than wild type plants ( P<.1, Kruskal-Wallis test with post hoc Dunn test, n=254-14). Error bars, SEM 3
1.4 1.2 SYN Seedling area, cm 2 1..8.6.4 SYN.2 1 2 3 4 Days post induction Supplemental Figure 4. Growth of SYN and ΔSYN following induction. 12 DAS seedlings were induced by submersion in 3 µm dexamethasone for 3 minutes and then photographed each day post induction for four days. Seedling area was determined in ImageJ. P<.5, two-way Student test, n=3 plants. Error bars, SEM. 4
Transcript abundance in total RNA 1 OX:RSH GFP 16S 23S RPS14 RPS18 TRNR TRNY RPOA RPOB PSAB PSAC PSBA PSBD PETB NDHF ATPB RBCL CLPP1 YCF1 YCF2 ACCD Translation PEP PSI PSII Supplemental Figure 5. qrt PCR analysis of plants overexpressing RSH3-GFP. qrt PCR for chloroplast transcripts in wildtype (dark green) and OX:RSH3-GFP.1 (OX:RSH3 GFP ) seedlings (light green) 12 DAS. Data are presented as means ± SEM for three independent biological replicates and are normalized to 18S, APT1, PP2A and ULP7 reference transcripts. Transcripts produced principally or partially by NEP are indicated in purple. P<.5, two-way Student test. 5
A Time, hrs.5 1 2 Puro Loading control Supplemental Figure 6. Proof of concept for puromycin labeling in plants. Puromycin is incorporated into cytosolic and chloroplastic proteins in a time dependent manner, and incorporation is inhibited by translation inhibitors. (A) Immunoblots of total Arabidopsis seedling proteins using a monoclonal anti-puromycin antibody (αpuro). 12-day old Arabidopsis seedlings were labeled with 5 µg/ml puromycin for the indicated time intervals before extraction of proteins, and equal quantities of protein were separated by SDS PAGE. Note the absence of a background signal in the unlabeled sample ( hrs). (B) Immunoblots of equal quantities of chloroplast total protein from 12 day old seedlings labelled with puromycin for 1 hr. Incorporation of puromycin is inhibited by the pretreatment with the cytosolic translation inhibitor cycloheximide (CHX, 1 µg/ml) and is further inhibited by the chloroplast translation inhibitor lincomycin (L, 1 mm). Note that although cycloheximide blocks cytosolic translation, it also introduces a significant background signal that is caused by the puromycylation of cycloheximide arrested nascent peptide chains (David et al., 212). This background is visible in the sample from seedlings treated with cycloheximide and lincomycin. Loading and transfer controls are RBCL stained with Ponceau red. 6
A B RSH1 At4g226 RSH2 At3g145 RSH3 At1g5413 CRSH At4g1747 SAIL_391_E11 rsh1-1 SAIL _35_B12 rsh2-1 SAIL_99_G5 rsh3-1 SAIL_1295_C4 crsh1-1 crsh-ami C 1.2 Relative expression 1.2.8.4 QM Relative expression.8.4 QMai QMaii RSH1 RSH2 RSH3 CRSH CRSH Supplemental Figure 7. Insertion sites and gene expression in the RSH mutants. (A) The insertion sites of the Arabidopsis TDNA insertion mutants used in this study. Insertions for RSH1, RSH2 and RSH3 are upstream of the conserved ppgpp synthase and hydrolase domains. The region of the CRSH transcript targeted by the amirna in crsh-ami is indicated. qrt PCR analysis of RSH gene expression in seedlings 12 DAS using primers downstream of the insertion sites in (B) the rsh1-1 rsh2-1 rsh3-1 crsh1-1 quadruple mutant (QM) and (C) the rsh1-1 rsh2-1 rsh3-1 crsh-ami quadruple mutants (QMai and QMaii). QMai and QMaii have independent TDNA insertions for crsh-ami. Primers for qrt PCR and mutant genotyping are listed in Supplemental Data Set 1. qrt PCR data are presented as means ± SEM for three independent biological replicates and transcript abundance was normalized to 18S and PP2A reference genes. 7
4 ppgpp, pmol/g fresh weight 3 2 1 QMaii OX:RSH1GFP.1 Supplemental Figure 8. ppgpp levels in QMaii and RSH1-GFP overexpressing plants were determined using a large scale extraction. ppgpp was extracted from seedlings grown on plates for 12 DAS and quantified by UPLC-MS, P<.1, two-way Student t-test versus. Data are presented as means ± SEM for four independent biological replicates. 8
A Transcript abudance 2 1 rsh1-1 DM-23 QMaii B 16S TRNR RBCL OX:RSH3 GFP rsh1-1 QMaii OX:RSH1 GFP C D Chloroplast area / cell area 1% 75% 5% 25% Rosette area, cm 2 8 4 % OX:RSH3 GFP OX:RSH1 GFP rsh1-1 DM-23 QM QMai QMaii Supplementantal Figure 9. Phenotypes of RSH mutants during vegetative growth. (A) qrt PCR for chloroplast transcripts in wildtype and mutant plants 12 DAS. Data are presented as means ± SEM for five independent biological replicates and transcript abundance was normalized to 18S, APT1, PP2A and ULP7 reference transcripts. Statistical analysis was performed using ANOVA with post hoc Dunnett tests versus the wildtype control. (B) Images of representative protoplasts from fully expanded leaves of plants grown on soil at 35 DAS (scale bar, 2 µm). Analysis of these protoplast populations is presented in Figure 6B. (C) Chloroplast plan area per cell area was analyzed in intact mesophyll cells 28 DAS as described previously (Pyke and Leech, 1991). Data were analyzed by the Kruskal-Wallis test with the Dunn test post hoc, 44 cells were analyzed for, 5 for OX:RSH1-GFP.1 and 2 for OX:RSH3-GFP.1 (D) The average rosette area for selected mutants after 24 days growth on soil under long day conditions. Data were analyzed by ANOVA with post hoc Dunnett tests versus the wildtype controls, n=16 plants. OX:RSH3 GFP, OX:RSH3-GFP.1; OX:RSH1 GFP, OX:RSH1-GFP.1; P<.1; error bars, SEM. 9
rsh1-1 QMai QMaii Supplemental Figure 1. RSH mutants show visible growth phenotypes under short day conditions. After flowering under short day conditions rsh1-1 plants rapidly become pale and show large numbers of senescent leaves compared to plants. In contrast, QMai and QMaii plants have small rosettes and darker leaves. The plants shown are 95 days old. 1
2 Absolute Expression 15 1 5 RSH1 RSH2 RSH3 CRSH Imbibed Seed, 24h Root Hypocotyl Cotyledon Leaf 1+2 Vegetative Rosette Cauline Leaf Senescing Leaf Flower Stage 15, Pedicels Flower Stage 15, Sepals Flower Stage 15, Petals Flower Stage 15, Stamens Flower Stage 15, Carpels Seed Stage 4 w/o Siliques Seed Stage 7 w/o Siliques Seed Stage 1 w/o Siliques Dry Seed Supplemental Figure 11. RSH2 and RSH3 are strongly expressed during senescence and late plant development. Microarray expression profiles of Arabidopsis RSH genes (displayed from left to right: RSH1, RSH2, RSH3 and CRSH) in different plant organs and at different stages of development. Data are presented as means ± SEM for three biological replicates. Data are from Schmid et al. (25) and were retrieved from Genevestigator (Zimmermann et al., 24). 11
A 1. B 1. Chl mg/g fresh weight.5 Chl mg/g fresh weight rsh1-1 DM-23 QM QMai QMaii OX:RSH1 GFP Supplemental Figure 12. Additional dark-induced senescence phenotypes. (A) CRSH may also contribute to the progression of dark-induced senescence. Chlorophyll levels in the leaves of wildtype and selected mutant lines following senescence induction. Prior to senescence induction plants used were grown under long day conditions for 3 days, and had just initiated flowering. This later developmental timepoint results in a faster progression of senescence than in Figure 7A. Chlorophyll loss was significantly greater in the wildtype than in DM-23, QM, QMai and QMaii (P<.1, n=3 plants). In addition the stay green phenotype of QMaii was significantly stronger than that of DM-23 suggesting that CRSH may also contribute during senescence despite its low level of expression, P<.5. Data were analyzed by ANOVA. (B) Plants overexpressing RSH1-GFP show a stay-green phenotype. Chlorophyll content in 27 day old and OX:RSH1-GFP.1 (OX:RSH1 GFP ) plants under normal growth conditions (dark green) or after senescence induction in the dark for three days (light green), P =.1 versus OX:RSH1-GFP.1 after 3 days in the dark, n=3 plants, two-way Student t-test; error bars, SEM. 12
Supplemental Figure 13. Natural senescence is affected in RSH mutants. Leaves were recovered from the base of the rosette of 95 day old plants grown under short day conditions and arranged in order of age from the oldest on the left. Gaps were left for missing leaves. Natural senescence is visible in the wild type, and appears enhanced in rsh1-1 and reduced in DM-23. QMaii leaves display an unusual senescence phenotype where they crumple and dry out while remaining green. 13
rsh1-1 DM-23 QM QMai QMaii Seed weight, ug Supplemental Figure 14. RSH mutants have altered seed weight suggesting defects in nutrient remobilization or seed development. 3-5 seeds per plant were counted and weighed for seven or more biological replicates. Data were analyzed by ANOVA with post hoc Dunnett tests versus the wildtype controls, P<.1; error bars, SEM. 14
A KDa M OX:RSH3 GFP OX:RSH1 GFP B KDa M DM23 T1 DM23 + ProRSH3:RSH3 L4 7 55 4 25 RBCL D6 1 7 55 4 RBCL 15.6.5.5 1. 1. 1. 1. 1.1 1.1 RBCS 25 1. 6.6 2.8.8 1.1 3.5 1.7 1.2 3.3 2.2 1.4 1.4 D4 7 55 4 25 RBCL 15.3.2.2 1.1.9 1. 1.8 1.8 1.6 RBCS D6 7 55 4 25 RBCL 15.6.9.5 1.4 1..6 6.4 6.1 6.2 RBCS Supplemental Figure 15. RuBisCO degradation is regulated by ppgpp during darkinduced senescence. (A) Equal quantities of total protein from, OX:RSH3-GFP.1 (OX:RSH3 GFP ) and OX:RSH1-GFP.1 (OX:RSH1 GFP ) plants were separated by SDS-PAGE and visualized by Coomassie Brilliant Blue after extraction from the leaves of selected lines after 4 days (D4) and 6 days (D6) of darkness. Plants had grown for 21 DAS at the start of treatment. Non-treated leaves were used as a control on day 4 (L4). Extractions from the leaves of three independent plants are shown for each line. (B) The leaves of, DM-23 and independent first generation (T1) DM-23 lines transformed with the genomic RSH3 (ProRSH3:RSH3) were analyzed as above after 6 days (D6) of darkness. Below each lane pixel densities for RBCL are shown, normalized to the wild type control on the same gel. 15
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