Transcriptome Analysis of Drought Induced Stress in <i>Chenopodium quinoa</i>

Abstract

Quinoa ( Chenopodium quinoa Willd.) is a halophytic, allotetraploid grain crop of the Amaranthaceae family with impressive drought tolerance, nutritional content and an increasing worldwide market. Here we report the re sults of an RNA-seq transcriptome analysis of Chenopodium quinoa using four water treatments (field capacity to drought) on the varieties “ Ingapirca ” (representing valley ecotypes) and “ Ollague ” (representing Altiplano Salares ecotypes). Physiological results, including growth rate, photosynthetic rate, stomatal conductance, and stem water potential, support the earlier findings that the Altiplano Salares ecotypes display greater tolerance to drought-like stress conditions than the valley ecotypes. cDNA libraries from root tissue samples for each variety × treatment combination were sequenced using Illumina Hi-Seq technology in an RNA-seq experiment. De novo assembly of the transcriptome generated 20,337 unique transcripts. Gene expression analysis of the RNA-seq data identified 462 putative gene products that showed differential expression based on treatment, and 27 puta tive gene products differentially expressed based on variety × treatment, including significant expression differ ences in root tissue in response to increasing water stress. BLAST searches and gene ontology analysis show an overlap between drought tolerance stress and other abiotic stress mechanisms.