RESUMEN

Sea Island cotton (Gossypium barbadense) is highly valued for its superior fiber qualities, especially fiber strength. Based on a transcript-derived fragment originated from transcriptome QTL mapping, a fiber strength related candidate gene of phosphatidylinositol 4-kinase cDNA, designated as GbPI4K, was first cloned, and its expression was characterized in the secondary cell wall thickening stage of G. barbadense fibers. The ORF of GbPI4K was found to be 1926 bp in length and encoded a predicted protein of 641 amino acid residues. The putative protein contained a clear PI3/4K kinase catalytic domain and fell into the plant type II PI4K cluster in phylogenetic analysis. In this study, the expression of cotton PI4K protein was also induced in Escherichia coli BL21 (DE3) as a fused protein. Semi-quantitative RT-PCR analysis showed that the gene expressed in the root, hypocotyl and leaf of the cotton plants. Real-time RT-PCR indicated that this gene in Sea Island cotton fibers expressed 10 days longer than that in Upland cotton fibers, and the main expression difference of PI4K between Sea Island cotton and Upland cotton in fibers was located in the secondary cell wall thickening stage of the fiber. Further analysis indicated that PI4K is a crucial factor in the ability of Rac proteins to regulate phospholipid signaling pathways.

Asunto(s)

1-Fosfatidilinositol 4-Quinasa/genética , Mapeo Cromosómico , Fibra de Algodón , Gossypium/enzimología , Gossypium/genética , Sitios de Carácter Cuantitativo/genética , Transcriptoma/genética , 1-Fosfatidilinositol 4-Quinasa/química , 1-Fosfatidilinositol 4-Quinasa/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas/genética , Datos de Secuencia Molecular , Especificidad de Órganos/genética , Filogenia , Células Procariotas/metabolismo , Estructura Terciaria de Proteína , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Especificidad de la Especie