Ubiquitin-specific protease 24 negatively regulates abscisic acid signalling in Arabidopsis thaliana.
Abscisic acid (ABA) is an important plant hormone integrating environmental stress and plant growth. Protein ubiquitination and deubiquitination are reversible processes catalysed by E3 ubiquitin ligase and deubiquitinating enzyme, respectively. Lots of E3 ubiquitin ligase and transcriptional factors modified by ubiquitination were reported to modulate ABA signalling. However, no deubiquitinating enzyme has been identified that functions in ABA signalling until now. Here, we isolated an ABA overly sensitive mutant, ubp24, in which the gene encoding ubiquitin-specific protease 24 (UBP24, At4g30890) was disrupted by a T-DNA insertion. The ubp24 mutant was hypersensitive to ABA and salt stress in both post-germinative growth and seedling growth. However, stomata closure in the ubp24 mutant was less sensitive to ABA, and the ubp24 mutant showed drought sensitivity. UBP24 possessed deubiquitinating enzyme activity, and the activity was essential for UBP24 function. Additionally, UBP24 formed homodimer in vivo. UBP24 was genetically upstream of ABI2, and the phosphatase activity of protein phosphatase 2C was decreased in the ubp24 mutant compared with the wild type in the presence of ABA. These results uncover an important regulatory role for the ubiquitin-specific protease in response to ABA and salt stress in plant.
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Jinfeng
J
Zhao
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.|College of Life Science, Sichuan University, Chengdu, 610064, China.
Huapeng
H
Zhou
College of Agriculture, Northeast Agricultural University, Harbin, 150030, China.|Heilongjiang Academy of Agricultural Sciences, Industrial Crop Institute, Harbin, 150086, China.
Ming
M
Zhang
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Yanan
Y
Gao
College of Life Sciences, Shenyang Agricultural University, Shenyang, 110161, China.
Long
L
Li
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Ying
Y
Gao
College of Agriculture, Northeast Agricultural University, Harbin, 150030, China.
Ming
M
Li
College of Life Sciences, Shenyang Agricultural University, Shenyang, 110161, China.
Yuhong
Y
Yang
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
Yan
Y
Guo
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Xueyong
X
Li
D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005816:Genetic Complementation Test; D018745:Genome, Plant; D018525:Germination / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology; D030821:Plants, Genetically Modified; D055503:Protein Multimerization / Q000187:drug effects; D000071636:Protein Phosphatase 2C; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects; D025801:Ubiquitin / Q000378:metabolism; D043222:Ubiquitin Thiolesterase / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; D025801:Ubiquitin; D012965:Sodium Chloride; D000040:Abscisic Acid; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C; C000611605:UBP24 protein, Arabidopsis; D043222:Ubiquitin Thiolesterase
ABA overly sensitive; deubiquitinating enzyme; drought sensitivity; protein phosphatase 2C; salt stress; stomata