Differentiated transcriptional signatures in the maize landraces of Chiapas, Mexico

Periodo de realización: 1900/01/01 al 2017/06/01

Tipo: Artículo científico

Lugar(es) de estudio: Frontera Comalapa, Chis., México, La Trinitaria, Chis., México, San Cristóbal de las Casas, Chis., México
Resumen: "Background: Landrace farmers are the keepers of crops locally adapted to the environments where they are cultivated.Patterns of diversity across the genome can provide signals of past evolution in the face of abiotic and biotic change.Understanding this rich genetic resource is imperative especially since diversity can provide agricultural security asclimate continues to shift.Results: Here we employ RNA sequencing (RNA-seq) to understand the role that conditions that vary across a landscapemay have played in shaping genetic diversity in the maize landraces of Chiapas, Mexico. We collected landraces fromthree distinct elevational zones and planted them in a midland common garden. Early season leaf tissue was collectedfor RNA-seq and we performed weighted gene co-expression network analysis (WGCNA). We then used associationanalysis between landrace co-expression module expression values and environmental parameters of landrace origin toelucidate genes and gene networks potentially shaped by environmental factors along our study gradient. Elevation oflandrace origin affected the transcriptome profiles. Two co-expression modules were highly correlated with temperatureparameters of landrace origin and queries into their ‘hub’ genes suggested that temperature may have led todifferentiation among landraces in hormone biosynthesis/signaling and abiotic and biotic stress responses. Weidentified several ‘hub’ transcription factors and kinases as candidates for the regulation of these responses.Conclusions: These findings indicate that natural selection may influence the transcriptomes of crop landraces alongan elevational gradient in a major diversity center, and provide a foundation for exploring the genetic basis of localadaptation. While we cannot rule out the role of neutral evolutionary forces in the patterns we have identified,combining whole transcriptome sequencing technologies, established bioinformatics techniques, and commongarden experimentation can powerfully elucidate structure of adaptive diversity across a varied landscape.Ultimately, gaining such understanding can facilitate the conservation and strategic utilization of crop geneticdiversity in a time of climate change."

Información de ECOSUR