ZnO-nanoparticles induce changes in the expression of genes associated with stress responses in spinach (Spinacia oleracea) without affecting Zn uptake

ABSTRACT: Purpose: To examine the gene expression within the spinach root tissues as a response to exposure to nanoparticles. Methods: Sequenced reads were processed using CLC Genomics Workbench 7.0. The reads were trimmed based on quality, length and ambiguity. Resulting reads were assembled into transcript assemblies. Sequence reads were mapped back to the constructed transcriptome. TAs were BLAST searched against a local blast database of coding sequences of Arabidopsis thaliana. Statistical analysis was performed using Baggerley’s test. Transcript assemblies were tested for gene enrichment using GO annotations and the functional categories were determined. MapMan was used to visualize gene expression data of TAs and study the biological pathways. Results: De novo assembly of the trimmed reads yielded 147,733 Transcript Assemblies (TA) with an average length of 645 bp. Largest TA was 16,379 bp. Approximately 89% of the quality trimmed reads from the different samples mapped successfully to the assembly reference. Gene expression data for spinach TAs homologous to Arabidopsis genes show upregulation of protein degradation pathways in the nano-ZnO treatment compared to the non-nanoZnO, this upregulation is coupled with a down regulation of the genes in the protein synthesis pathways crucial role in the spinach plant responses to ZnO nanoparticle exposure. Genes associated (REDOX, signaling and transcription factors) with responses to stresses (both abiotic and biotic) were upregulated upon exposure to ZnO nanoparticles. Additionally genes in biosynthesis pathways of jasmonate and gibberellins genes were up-regulated upon exposure to ZnO nanoparticles in spinach. Conclusions: A de novo transcriptome was developed for spinach. When spinach plants were exposed to ZnO nanoparticles, they seem to sense the nanoparticles similarly to external chemicals or pathogens and induced production of reactive oxygen species. Hormone signaling pathways were activated leading to the induced expression of hormones with different roles in defense.

ORGANISM(S): Spinacia oleracea

PROVIDER: GSE72912 | GEO | 2018/09/10

REPOSITORIES: GEO