O uso de estratégias multi-ômicas para estudar as respostas das plantas de dendê (Elaeis guineensis Jacq.) a estresses abióticos (seca e salinidade) e ao amarelecimento fatal (AF)

Abstract

The African oil palm or oil palm (Elaeis guineensis) is an oilseed of great economic and social importance. In Brazil, oil palm cultivation in the Cerrado is feasible, but requires artificial irrigation due to the prolonged drought in this region. In this context, abiotic stresses, such as drought and salinity, pose challenges due to water scarcity and salinization of irrigated soils. Fatal yellowing (FY), a disorder with no known cause, is a limitation for African oil palm production in Brazil. Thus, the present study aimed to use a comprehensive and largescale analysis of single-omics analysis (SOA) and multi-omics integration (MOI) to study the response of oil palm to abiotic stresses (drought and salinity) and to Fatal Yellowing (FY). For the study, leaf samples of young oil palm under salt stress (12 days) and water deprivation (14 days) were collected to perform RNA-seq, UHPLC-MS and LC-MS/MS analyses, for transcriptomics, metabolomics and proteomics, respectively. For the FY study, leaves and soil of asymptomatic and symptomatic plants were collected in the dry and rainy season in Santa Bárbara do Pará, Pará, Brazil. For leaf material, RNA-seq and metabolomics analyzes were performed. For the soil, an analysis of the structure and chemical composition was carried out. For salinity, a total of 129 metabolites, 436 complete transcripts and 74 proteins representing enzymes were differentially expressed. For drought, 269 metabolites, 1955 complete transcripts and 131 proteins were differentially expressed. Similarities and dissimilarities were found in the response of oil palm to salt stress and drought. MOI analysis revealed a list of impacted pathways, but we highlighted cysteine and methionine metabolism (map00270) as the most impacted pathway in both stresses and correlation analysis revealed 91.55% similarities in qualitative profiles. For FY, the metabolite and physical-chemical profiles of the soil and leaves did not justify the differences in the phenotype of the plants. In all, the single-omics analysis (SOA) performed in the present study allowed the identification of 320 enzymes (from transcriptome analysis) and 254 metabolites in the leaves of oil palm plants subjected to multi-omics integration analysis (MOI). This MOI analysis produced a list of 27 metabolic pathways affected by the change from dry to wet season, having at least ten differentially expressed enzymes and metabolites. A set of 56 proteins/genes, down- or upregulated in symptomatic versus asymptomatic plants, regardless of season, provide evidence of disruptions in host resistance to non-adapted pathogens and in basal immunity to adapted pathogens, caused by the anaerobic conditions faced by plants. Finally, our results allow us to indicate candidate genes for the genetic engineering of crop species resistant to both stresses. For FY, although our data do not really reveal the nature of the disease, the identified molecular components may open new doors to produce materials resistant to this disease and create an early diagnosis system.