RESUMEN
The stearoyl-ACP desaturase (SACPD) is a key enzyme in the regulation of saturated to unsaturated fatty acid ratio, playing a crucial role in regulating membrane stability and fluidity, as well as photosynthesis efficiency, which makes it an important research focus in crop species. This study reports the characterization and molecular cloning of pale dwarf (pad), a new tomato (Solanum lycopersicum L.) T-DNA recessive mutant, which exhibits a dwarf and chlorotic phenotype. Functional studies of the T-DNA tagged gene were conducted, including phylogenetic analysis, expression and metabolomic analyses, and generation of CRISPR/Cas9 knockout lines. The cloning of T-DNA flanking genomic sequences and a co-segregation analysis found the pad phenotype was caused by a T-DNA insertion disrupting the tomato homologue of the Arabidopsis SUPPRESSOR OF SALICYLIC ACID INSENSITIVITY 2 (SlSSI2), encoding a plastid localized isoform of SACPD. The phenotype of CRISPR/Cas9 SlSSI2 knockout lines confirmed that the morphological abnormalities in pad plants were due to SlSSI2 loss of function. Functional, metabolomic and expression analyses proved that SlSSI2 disruption causes deficiencies in 18:1 fatty acid desaturation and leads to diminished jasmonic acid (JA) content and increased salicylic acid (SA) levels. Overall, these results proved that SSI2 plays a crucial role in the regulation of polyunsaturated fatty acid profiles in tomato, and revealed that SlSSI2 loss of function results in an inhibited JA-responsive signalling pathway and a constitutively activated SA-mediated defence signalling response. This study lays the foundation for further research on tomato SACPDs and their role in plant performance and fitness.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Solanum lycopersicum , Ácidos Grasos/metabolismo , Proteínas de Arabidopsis/metabolismo , Solanum lycopersicum/genética , Ácido Graso Desaturasas/genética , Ácido Graso Desaturasas/metabolismo , Filogenia , Mutación con Pérdida de Función , Arabidopsis/genética , Oxilipinas/metabolismo , Ciclopentanos/farmacología , Ácido Salicílico/metabolismo , Crecimiento y Desarrollo , Enfermedades de las Plantas/genética , Regulación de la Expresión Génica de las PlantasRESUMEN
An optimised Agrobacterium-mediated gene transfer protocol was developed in order to obtain watermelon transgenic plants [Citrullus lanatus (Thunb.) Matsun. & Nakai.]. Transformation efficiencies ranged from 2.8% to 5.3%, depending on the cultivar. The method was applied to obtain genetically engineered watermelon plants expressing the Saccharomyces cerevisiae HAL1 gene related to salt tolerance. In order to enhance its constitutive expression in plants, the HAL1 gene was cloned in a pBiN19 plasmid under control of the 35S promoter with a double enhancer sequence from the cauliflower mosaic virus and the RNA4 leader sequence of the alfalfa mosaic virus. This vector was introduced into Agrobacterium tumefaciens strain LBA4404 for further inoculation of watermelon half-cotyledon explants. The introduction of both the neomycin phosphotransferase II and HAL1 genes was assessed in primary transformants (TG1) by polymerase chain reaction analysis and Southern hybridisation. The expression of the HAL1 gene was determined by Northern analysis, and the diploid level of transgenic plants was confirmed by flow cytometry. The presence of the selectable marker gene in the expected Mendelian ratios was demonstrated in TG2 progenies. The TG2 kanamycin-resistant plantlets elongated better and produced new roots and leaves in culture media supplemented with NaCl compared with the control. Salt tolerance was confirmed in a semi-hydroponic system (EC=6 dS m(-1)) on the basis of the higher growth performance of homozygous TG3 lines with respect to their respective azygous control lines without the transgene. The halotolerance observed confirmed the inheritance of the trait and supports the potential usefulness of the HAL1 gene of S. cerevisiae as a molecular tool for genetic engineering of salt-stress protection in other crop species.
Asunto(s)
Citrullus/genética , Expresión Génica , Plantas Modificadas Genéticamente/fisiología , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Northern Blotting , Southern Blotting , Citrullus/fisiología , ADN Bacteriano/genética , Técnicas de Transferencia de Gen , Péptidos y Proteínas de Señalización Intracelular , Kanamicina Quinasa/genética , Cloruro de SodioRESUMEN
Propósito: el cáncer de ovario constituye la principal causa de muerte por cáncer ginecológico; el colorectal en la mujer, es la segunda causa de muerte por cáncer. Puesto que comparten sintomatología, es frecuente que sea el ginecólogo quien llegue al diagnóstico de cáncer de colon. Material y métodos: se presentan cuatro casos de pacientes diagnosticadas inicialmente de tumores ováricos y que se trataron de carcinomas de colon. Se revisa la Bibliografía existente. Resultados: A partir de los 40 años se debe pensar en la posibilidad del cáncer de colon en el diagnóstico de masas pélvicas. Conclusiones: Es necesario establecer el diagnóstico diferencial entre carcinoma de colon y ovárico, utilizando para ello los procedimientos diagnósticos que sean necesarios (AU)