Fig.1

Schematic diagram of pKI1.1 R vector and target sites of AtMST1 geneA. Structure of pKI1.1 R vector； LB. T-DNA left border； RB. T-DNA right border； HygR. Hygromycin resistance gene； U6.26 promoter； U6.26 promoter driving sgRNA expression. B. Gene structure of AtMST1 and sgRNA target sites； gray boxes. 5' and 3'-untranslated regions； black boxes. Exons； black lines. Introns； lowercase letters. Locations of gRNA target sequences.

Table 1

All primers appearing in the text

Fig.2

Colony PCR analysis of pKI1.1 R-AtMST1M. 2 000 DNA marker； -. Negative control； 1-5. Colony PCR identification of different single colonies； CR. CRISPR； CR1，CR2，CR3，and CR4. Four independent gene-editing vectors.

Fig.3

Screening of AtMST1-CRISPR transgenic linesA-D. Representative T1 generation transgenic plants of AtMST1-CR1/2/3/4 lines， respectively； WT. Wild type.

Fig.4

Molecular identification of AtMST1-CRISPR gene-edited plantsM. 2 000 DNA marker； CK. Negative control； WT. Wild type； numbers. Representative independent transgenic lines； CR. CRISPR； CR1，CR2，CR3，and CR4. Four independent gene-editing vectors. Upper panel（A-D）. PCR products amplified with primers CAS9-F/CAS9-R， showing the presence of the Cas9 gene； lower panel（E-H）. PCR products amplified with primers pKI1.1R-F/AtMST1-R，confirming the insertion of the target gene fragment.

Fig.5

Sequence analysis of AtMST1 gene-edited plantsA-B. Mutation profiles of the target sites； C. Impact of the nucleotide mutations on the amino acid sequence； D. Sequencing verification of the target site in the T3 homozygous mutant.

Table 2

Analysis of editing efficiency at the target site in the AtMST1-CR3-2 line by single-clone sequencing

Fig.6

The H2S production rate and content in atmst1 mutantsA. Representative images of H2S detection in roots using the 7-Azido-4-methylcoumarin（AzMc） fluorescent probe；B.Quantitative analysis of fluorescence intensity shown in（A） using Image J software；C. H2S content in wild-type（WT） and atmst1 mutant plants measured by the methylene blue assay；D.Endogenous H2S production rate in WT and atmst1 mutants determined by the methylene blue method. Data were presented as mean±SD. Asterisks indicated significant differences（**.P<0.01） as determined by Student’s t-test.

Fig.7

Loss of AtMST1 function led to salt sensitivity and increased ROS accumulation in Arabidopsis seedlingsA. Phenotypes of WT and atmst1 mutant plants grown under control（CK） or 100 mmol?L-1 NaCl conditions for 14 days； B. Quantitative analysis of root length for seedlings shown in（A）； C. Representative fluorescence microscope images of seedling root tips stained with the ROS fluorescent probe DCFH-DA； D. Quantitative analysis of relative fluorescence intensity of ROS in root tips of WT and atmst1 seedlings under salt stress. Data were mean±SD， different lowercase letters indicated significant differences（P<0.05）.