ABSTRACT
Glycoside Hydrolase 3 (GH3) is a phytohormone-responsive family of proteins found in many plant species. These proteins contribute to the biological activity of indolacetic acid (IAA), jasmonic acid (JA), and salicylic acid (SA). They also affect plant growth and developmental processes as well as some types of stress. In this study, GH3 genes were identified in 48 plant species, including algae, mosses, ferns, gymnosperms, and angiosperms. No GH3 representative protein was found in algae, but we identified 4 genes in mosses, 19 in ferns, 7 in gymnosperms, and several in angiosperms. The results showed that GH3 proteins are mainly present in seed plants. Phylogenetic analysis of all GH3 proteins showed three separate clades. Group I was related to JA adenylation, group II was related to IAA adenylation, and group III was separated from group II, but its function was not clear. The structure of the GH3 proteins indicated highly conserved sequences in the plant kingdom. The analysis of JA adenylation in relation to gene expression of GH3 in potato (Solanum tuberosum) showed that StGH3.12 greatly responded to methyl jasmonate (MeJA) treatment. The expression levels of StGH3.1, StGH3.11, and StGH3.12 were higher in the potato flowers, and StGH3.11 expression was also higher in the stolon. Our research revealed the evolution of the GH3 family, which is useful for studying the precise function of GH3 proteins related to JA adenylation in S. tuberosum when the plants are developing and under biotic stress.
Subject(s)
Cyclopentanes/metabolism , Genome, Plant , Glycoside Hydrolases/genetics , Oxylipins/metabolism , Phylogeny , Plant Proteins/genetics , Solanum tuberosum/genetics , Amino Acid Sequence , Bryophyta/enzymology , Bryophyta/genetics , Chlorophyta/enzymology , Chlorophyta/genetics , Conserved Sequence , Cycadopsida/enzymology , Cycadopsida/genetics , Evolution, Molecular , Ferns/enzymology , Ferns/genetics , Gene Expression , Gene Ontology , Glycoside Hydrolases/metabolism , Indoleacetic Acids/metabolism , Isoenzymes/genetics , Isoenzymes/metabolism , Magnoliopsida/enzymology , Magnoliopsida/genetics , Molecular Sequence Annotation , Plant Growth Regulators/metabolism , Plant Proteins/metabolism , Salicylic Acid/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Solanum tuberosum/classification , Solanum tuberosum/enzymology , Solanum tuberosum/growth & developmentABSTRACT
Although the palynology and sporophyte stage of Isöetes sinensis have been well studied, the biology of its gametophyte and embryo is less well understood. To date, the functions of several genes of I. sinensis and the molecular mechanisms of enzymes encoded by them remain to be studied. In the present study, the Fe-SOD gene of I. sinensis was successfully cloned using RT-PCR and rapid amplification of cDNA ends (RACE), and termed IsFeSOD. IsFeSOD has certain reference value in the classification of system evolution. The study also accumulated data for further research on the SOD gene. Bioinformatic analysis was employed to compare IsFeSOD with gene sequences obtained from other plants present in the GenBank. Furthermore, the recombinant pET32-FeSOD plasmids were transformed into Escherichia coli BL21 for expression. IsFeSOD was observed to have 1469 nucleotides that were predicted to encode 247 amino acids. The bioinformatic analysis revealed that IsFeSOD contained conserved TGGGA sequences, similar to eight other species, in addition to five other conserved sequences. The recombinant protein was about 43 kDa. Recombinant FeSOD was expressed, purified, and confirmed by western blotting. Alignment of complete Fe-SOD mRNA sequences from 9 species revealed several conserved sequences. A phylogenetic tree was constructed using MEGA4.1 and ClustalX multiple-sequence alignment programs. This study could be helpful in further characterization of SOD genes and for classification of system evolution status.
Subject(s)
Bryophyta/enzymology , Bryophyta/genetics , Gene Expression Regulation, Plant , Superoxide Dismutase/genetics , Amino Acid Sequence , Base Sequence , Blotting, Western , Cloning, Molecular , DNA, Complementary/genetics , Gene Expression Regulation, Enzymologic , Phylogeny , Recombinant Proteins/metabolism , Sequence Alignment , Superoxide Dismutase/chemistry , Superoxide Dismutase/metabolismABSTRACT
Atmospheric nitrogen deposition can cause major declines in bryophyte abundance yet the physiological basis for such declines is not fully understood. Bryophyte physiological responses may also be sensitive bioindicators of both the impacts of, and recovery from, N deposition. Here, responses of tissue nutrients (nitrogen (N), phosphorus (P) and potassium (K): NPK), N and P metabolism enzymes (nitrate reductase and phosphomonoesterase), photosynthetic pigments, chlorophyll fluorescence, sclerophylly and percentage cover of two common bryophytes (Pseudoscleropodium purum and Rhytidiadelphus squarrosus) to long-term (11 yr) enhanced N deposition (+3.5 and +14 g N m(-2) yr(-1)) are reported in factorial combination with P addition. Recovery of responses 22 months after treatment cessation were also assessed. Enhanced N deposition caused up to 90% loss of bryophyte cover but no recovery was observed. Phosphomonoesterase activity and tissue N:P ratios increased up to threefold in response to N loading and showed clear recovery, particularly in P. purum. Smaller responses and recovery were also seen in all chlorophyll fluorescence measurements and altered photosynthetic pigment composition. The P limitation of growth appears to be a key mechanism driving bryophyte loss along with damage to photosystem II. Physiological measurements are more sensitive than measurements of abundance as bioindicators of N deposition impact and of recovery in particular.