RESUMO
A cDNA encoding translationally controlled tumor protein (TCTP) of Jatropha curcas L., JcTCTP, was isolated from an endosperm cDNA library. JcTCTP consisted of a 5' untranslated region (UTR) of 526 bp, a 3' UTR of 377 bp and an open reading frame (ORF) of 507 bp, encoding a protein of 168 amino acid residues, which contained two signature sequences of TCTP family. Its deduced amino acid sequence was similar to the other known plants TCTPs in a range of 77.4-92.3%. Expression of JcTCTP was the highest in the stem, endosperm at embryo formation stage and embryo of J. curcas tissues, and the lowest in the endosperm at seminal leaf embryo stage and flower, demonstrating a pattern of temporal and spatial specific expression.
Assuntos
Biomarcadores Tumorais/genética , DNA Complementar/genética , DNA Complementar/metabolismo , Jatropha/genética , Jatropha/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Animais , Biomarcadores Tumorais/metabolismo , Clonagem Molecular , Jatropha/anatomia & histologia , Jatropha/química , Fases de Leitura Aberta , Proteína Tumoral 1 Controlada por TraduçãoRESUMO
To date, two types of ribosome-inactivating proteins (RIPs) have been found in Jatropha curcas. One is curcin, which has been isolated from the endosperm, and the other is curcin-L, which is expressed in leaves upon stress treatment. Phylogenetic analysis of the predicted amino acid sequences of the RIPs in plants revealed that these belong to a major subfamily and are close to trichosanthin (TCS). Studies on the mRNA and protein levels showed that both curcin and curcin-L have an organ-specific expression pattern. Curcin is only expressed and accumulated in the endosperm; its expression begins in the globular embryo period and peaks during the mature embryo period. In contrast, curcin-L is only expressed in the leaves, but its expression is induced by certain conditions such as treatment with phytohormones or polyethylene glycol, exposure to high and low temperatures, and fungal infection. Analysis of the 5' flanking regions of curcin and curcin-L revealed that the 5' flanking region of curcin-L has three major inserted fragments, which are not present in the corresponding region of curcin. Comparison of characteristic cis-elements suggests the presence of several motifs that are involved in the endosperm-specific expression in the 5' flanking region of curcin, while in curcin-L some stress- and defense-responsive motifs are found to be mainly located in the three inserted fragments. Comparison of the antifungal activity of the two RIPs showed that the one of curcin-L is higher than that of curcin. Differences in the expression and activity of curcin and curcin-L suggest that these two RIPs have different functions.
Assuntos
Perfilação da Expressão Gênica , Jatropha/genética , Proteínas Inativadoras de Ribossomos Tipo 1/genética , Regiões 5' não Traduzidas/genética , Antifúngicos/farmacologia , Primers do DNA , DNA de Plantas/genética , Endosperma/genética , Endosperma/metabolismo , Jatropha/metabolismo , Filogenia , Reação em Cadeia da Polimerase , Proteínas Recombinantes/metabolismo , Proteínas Inativadoras de Ribossomos Tipo 1/metabolismo , Proteínas Inativadoras de Ribossomos Tipo 1/farmacologiaRESUMO
Ribosome-inactivating proteins (RIPs) represent a type of protein that universally inactivates the ribosome thus inhibiting protein biosynthesis. Curcin-L was a type I RIP found in Jatropha curcas L.. Its expression could be activated in leaves by treatments with abscisic acid, salicylic acid, polyethylene glycol, temperature 4, 45 degrees C and ultraviolet light. A 654 bp fragment of a 5' flanking region preceding the curcin-L gene, designated CP2, was cloned from the J. curcas genome and its expression pattern was studied via the expression of the beta-glucuronidase (GUS) gene in transgenic tobacco. Analysis of GUS activities showed that the CP2 was leaf specific, and was able to drive the expression of the reporter gene under stress-induction conditions. Analysis of a series of 5'-deletions of the CP2 suggested that several promoter motifs were necessary to respond to environmental stresses.
Assuntos
Regulação da Expressão Gênica de Plantas , Jatropha/genética , Nicotiana/genética , Folhas de Planta/genética , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas/genética , Proteínas Inativadoras de Ribossomos Tipo 1/genética , Ácido Abscísico/farmacologia , Fluorometria , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Jatropha/efeitos dos fármacos , Jatropha/efeitos da radiação , Dados de Sequência Molecular , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos da radiação , Polietilenoglicóis/farmacologia , Ácido Salicílico/farmacologia , Estresse Fisiológico , Temperatura , Nicotiana/efeitos dos fármacos , Nicotiana/efeitos da radiação , Raios UltravioletaRESUMO
Water channel proteins, aquaporins, play fundamental roles in transmembrane water movements in plants. A new full-length cDNA encoding aquaporin was isolated from the seedlings of Jatropha curcas. The gene of the plasma membrane intrinsic protein (PIP) from J. curcas (JcPIP2) contained an 843 bp open reading frame encoding a protein of 280 amino acids. The amino acid sequence showed 94% identity with Ricinus communis PIP. Injection of JcPIP2 complementary RNA into Xenopus oocytes increased 10-fold the osmotic water permeability of the oocytes. Immunodetection of JcPIP2 with anti-JcPIP2 antibody indicated that this protein is ubiquitously located in all tested tissues of the plant. To investigate the relationship between aquaporins and drought resistance in J. curcas, the abundance of JcPIP2 was examined in seedlings of two J. curcas populations, GaoYou CSC63 and YanBian S1, under water deficit with PEG6000. Under field conditions, those two populations, GaoYou CSC63 was resistant to water deficit, but YanBian S1 was sensitive to water deprivation. With the increasing degree of drought stress, JcPIP2 level increased in seedlings of GaoYou CSC63, whereas there was no significant change in seedlings of YanBian S1. Compared with YanBian S1, GaoYou CSC63 also showed higher root hydraulic conductivity and lower decreasing trend in the seedlings under water deficit. These results indicated that JcPIP2 probably played a role in drought resistance in J. curcas.