RESUMO
Directly electrochemically reduced graphene oxide (ERGO) was obtained by potentiostatic reduction of exfoliated graphene oxide sheets on a glassy carbon electrode (GCE). The ERGO-modified electrode (ERGO/GCE) displayed greatly improved voltammetric response to the amino acids l-tryptophane (Trp) and l-tyrosine (Tyr) compared with the chemically reduced graphene oxide (CRGO) modified electrode. The ERGO/GCE separated the voltammetric responses of ascorbic acid (AA) and uric acid (UA) from that of Trp and Tyr. It eliminated the interference from AA and UA. The electrode showed good reproducibility and was used to determine Trp and Tyr with linear ranges of 0.2-40.0 µmol L(-1)and 0.5-80.0 µmol L(-1), detection limits of 0.1 µmol L(-1) and 0.2 µmol L(-1), respectively.
Assuntos
Grafite/química , Triptofano/análise , Tirosina/análise , Ácido Ascórbico/química , Soluções Tampão , Eletroquímica , Eletrodos , Indicadores e Reagentes , Reprodutibilidade dos Testes , Análise Espectral Raman , Ácido Úrico/químicaRESUMO
The homozygous T-DNA mutant of the PP2CA2 gene in Arabidopsis thaliana was identified at DNA and RNA levels. The semi-quantitative RT-PCR analysis showed expression of PP2CA2 was induced by NaCl and ABA. When grown in presence of increasing concentration of exogenous ABA the pp2ca2 mutant showed a significant loss of ABA sensitivity in terms of seed germination, efficiency of post-germination growth and root growth. In presence of all ABA and NaCl concentrations tested the germination percentage of wild-type seeds was lower than that of mutant ppca2 seeds. Furthermore, in the presence of exogenous ABA, the pp2ca2 seeds showed higher germination percentages than wild-type at different stages of development and the pp2ca2 seedlings showed a reduced inhibition of root growth compared with wild-type plants. The above results indicated that the pp2ca2 was an ABA-hyposensitive mutant.
Assuntos
Ácido Abscísico/metabolismo , Arabidopsis/genética , Fosfoproteínas Fosfatases/genética , Ácido Abscísico/farmacologia , Aclimatação/genética , Sequência de Aminoácidos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Análise Mutacional de DNA , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Germinação/genética , Isoenzimas/genética , Dados de Sequência Molecular , Proteínas Mutantes/genética , Homologia de Sequência de Aminoácidos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genéticaRESUMO
A casein kinase 1 protein gene, CK1A, was isolated from Arabidopsis seedlings by RT-PCR method. This gene contains an open reading frame of 2,112 bp, which encodes 703 amino acids. The plant expression vector of 35S: GFP: CK1A was constructed by the Gateway System. The 35S: GFP: CK1A fusion protein was localized to the nucleus in onion epidermal cell, indicating that the product of CK1A gene plays a role in the cell nucleus. The semi-quantitative RT-PCR analysis showed that CK1A was highly expressed in flowers, stems and roots, but less in leaves and leafstalks. The yeast two-hybrid analysis demonstrated that CK1A and CRY2 can interact in vivo under blue light, which indicates that CK1A may play an important role in blue light signal induction of Arabidopsis.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Caseína Quinase I/metabolismo , Proteínas de Arabidopsis/classificação , Proteínas de Arabidopsis/genética , Criptocromos/genética , Criptocromos/metabolismo , Regulação da Expressão Gênica de Plantas , Filogenia , Ligação Proteica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Técnicas do Sistema de Duplo-HíbridoRESUMO
A number of signal pathways have been found through which abundant calcium-stimulated protein kinase activity in plant is associated with calcium-dependent protein kinases (CDPKs) which act as the calcium sensors mediating numerous responses, including hormone signaling. Basing on previous studies, we made additional functional analysis of the gene AtCPK30 encoding a protein kinase in Arabidopsis. Results of semi-quantitative reverse transcription PCR (RT-PCR) analysis indicated that AtCPK30 was highly expressed in root and induced by ABA, IAA, 2,4-D, GA(3) and 6-BA treatment. The physiological roles of AtCPK30 were studied using a gain-of-function approach. Seedlings of AtCPK30 transgenic lines had longer primary roots than those plants of wild-type at the early stages. Interestingly, when these plants grew on MS lack of Ca(2+) including wild-type and transgenic lines, the roots of transgenic line were more sensitive to calcium, lack of Ca(2+) had less effect on roots of transgenic lines than those of wild-type. Treated with several plant hormones, such as ABA, IAA, GA(3) and 6-BA, the roots of seedlings of transgenic line developed abnormally because they were more sensitive to hormones. Furthermore, NPA relatively less inhibited emergency of lateral roots of transgenic line than those of the wild-type. Green fluorescent protein-CPK30 (GFP-CPK30) fusion protein studies revealed the localization of AtCPK30 to both cell wall and plasma membrane. These results suggest that AtCPK30 acts as the calcium sensor and involved in the hormone-signaling pathways.