Transcriptoma de Solanum goniocalix para la identificación de genes candidatos de resistencia al Tizón tardío

Abstract

Con el objetivo de identificar genes candidatos para resistencia a Phytophthora infestans, en papas nativas locales (PNL) de tres poblaciones de Ayacucho (Anco, Chungi y Ticllas), se evaluo la diversidad genetica de 144 PNL. Con 10 marcadores SSR se distinguieron 67 alelos polimorficos, 14 genotipos y 18 alelos unicos. El AMOVA mostro que el 27.92 % de la diversidad alelica esta distribuida entre las poblaciones, y el 72.08 % esta distribuido dentro de las poblaciones, con FST promedio de 0.279. Se encontro alta diversidad intra e inter poblacional, y cada una constituyen poblaciones geneticamente cerradas. Se fenotiparon 20 accesiones de papa nativa expuesta a P. infestans POX-67. Se seleccionaron las accesiones Wira Pasna (CIP 704270) y Sumaq Perqa (CIP 703777) de la especie Solanum goniocalix, como resistente y susceptible, respectivamente. Las dos accesiones seleccionadas fueron inoculadas con P. infestans POX-67, se extrajo ARN de muestras foliares a 0 y 48 hpi. En el transcriptoma (Solanum goniocalix) se cuantifico 40,336 transcritos en las librerias ARNseq, cada libreria con una profundidad promedio de 28.02 millones de lecturas (secuenciamiento Illumina). Las lecturas se alinearon al genoma de referencia con una eficiencia de mapeo de 92.01%. Se reportan 19,666 genes alineados que no distorsionan el modelamiento en todas las repeticiones y al menos en un tratamiento. En la accesion resistente CIP-704270 (Wira Pasna) se identificaron 303 genes relacionados con la resistencia a P. infestans. Considerando la direccion de su expresion diferencial, se contabilizo 136 genes sobre-expresados y 167 genes sub-expresados, relacionados a resistencia en S. goniocalix a P. infestans (Log2FC . 2 y FDR . 0.001). Del analisis de enriquecimiento GO (Gene Ontology) y de rutas metabolicas KEGG (Kyoto Encyclopedia of Genes and Genomes) se identificaron 20 genes candidatos relacionados a resistencia contra P. infestans POX-67 a 48 hpi.With the aim of identifying resistance genes candidates against Phytophthora infestans, in native potatoes landrace (NPL) of three populations of Ayacucho (Anco, Chungi and Ticllas). The genetic diversity of 144 NPL was evaluated. A total 10 SSR markers were screened and produced 67 polymorphic alleles, 14 genotypes and 18 unique alleles were distinguished. The AMOVA test showed that 27.92% of allelic diversity was distributed among populations, and 72.08% within populations, with an average FST of 0.279. High intra and inter populational diversity was found, and each constitute genetically closed populations. Twenty native potato accessions were phenotyped after being exposed to P. infestans POX-67. Accessions Wira Pasna (CIP 704270) and Sumaq Perqa (CIP 703777) of the Solanum goniocalix species were selected as resistant and susceptible samples, respectively. The two selected accessions were inoculated with P. infestans POX-67. RNA was extracted from samples at 0 and 48 hpi. In the transcriptome (Solanum goniocalix), 40,336 transcripts within the RNAseq libraries, each library with an average depth of 28.02 million readings (Illumina sequencing). Reads were aligned at reference genome with a mapping efficiency of 92.01%. In total 19,666 aligned genes were kept for downstream analysis that had more than 10 reads per library in at least three biological replicates. In the resistant accession CIP-704270 (Wira Pasna) 303 resistance-related genes to P. infestans were identified. Considering the direction of its differential expression, 136 up-expressed genes and 167 down-expressed genes as resistance S. goniocalix to P. infestans (Log2FC . 2 and FDR . 0.001). From the GO (Gene Ontology) enrichment analysis and KEGG metabolic pathways (Kyoto Encyclopedia of Genes and Genomes), 20 candidate resistance-related genes against P. infestans POX-67 were identified at 48 hpi.