Functional characterization of a plastid-specific ribosomal protein PSRP2 in Arabidopsis thaliana under abiotic stress conditions.
Plastids possess a small set of proteins unique to plastid ribosome, named plastid-specific ribosomal proteins (PSRPs). Among the six PSRPs found in Arabidopsis thaliana, PSRP2 is unique in that it harbors two RNA-recognition motifs found in diverse RNA-binding proteins. A recent report demonstrated that PSRP2 is not essential for ribosome function and plant growth under standard greenhouse conditions. Here, we investigated the functional role of PSRP2 during Arabidopsis seed germination and seedling growth under different light environments and various stress conditions, including high salinity, dehydration, and low temperature. The transgenic Arabidopsis plants overexpressing PSRP2 showed delayed germination compared with that of the wild-type plants under salt, dehydration, or low temperature stress conditions. The T-DNA insertion psrp2 mutant displayed better seedling growth but PSRP2-overexpressing transgenic plants showed poorer seedling growth than that of the wild-type plants under salt stress conditions. No noticeable differences in seedling growth were observed between the genotypes when grown under different light environments including dark, red, far-red, and blue light. Interestingly, the PSRP2 protein possessed RNA chaperone activity. Taken together, these results suggest that PSRP2 harboring RNA chaperone activity plays a role as a negative regulator in seed germination under all three abiotic stress conditions tested and in seedling growth of Arabidopsis under salt stress but not under cold or dehydration stress conditions.
Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
Tao
T
Xu
Kwanuk
K
Lee
Lili
L
Gu
Jeong-Il
JI
Kim
Hunseung
H
Kang
D000222:Adaptation, Physiological / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002736:Chloroplasts / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D004269:DNA, Bacterial; D003681:Dehydration; D055864:Droughts; D017343:Genes, Plant; D005838:Genotype; D018525:Germination / Q000235:genetics; D008027:Light; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D016254:Mutagenesis, Insertional; D030821:Plants, Genetically Modified; D016601:RNA-Binding Proteins / Q000737:chemistry; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D055049:Salt Tolerance / Q000235:genetics*; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D012965:Sodium Chloride / Q000009:adverse effects; D013312:Stress, Physiological / Q000235:genetics; D014867:Water
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018832:Molecular Chaperones; C000589952:PSRP2 protein, Arabidopsis; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; C036483:T-DNA; D014867:Water; D012965:Sodium Chloride
Abiotic stress; Arabidopsis thaliana; PSRP; Plastic-specific ribosomal protein; RBP; RNA-binding protein; RNA-recognition motif; RRM; Ribosome function; plastid-specific ribosomal protein