Transcriptomic changes and signalling pathways induced by arsenic stress in rice roots

Abstract

Arsenic (As) is considered the most common toxic metalloid, but its molecular mode of action is not well understood. We investigated whether arsenate [As(V)] can induce intracellular reactive oxygen species production and calcium oscillation in rice roots. To better understand the molecular basis of plant cell responses to As, we performed a large-scale analysis of the rice transcriptome during As(V) stress. As(V) induced genes involved in abiotic stress, detoxification pathways and secondary metabolic process. Genes involved in secondary cell wall biogenesis, cell cycle and oligopeptide transport were mainly downregulated. Genes encoding signalling components such as receptor-like cytoplasmic kinases protein kinase, APETALA2/ethylene response factor, heat shock factor, MYB and zinc-finger protein expressed in inflorescence meristem transcription factors were increased in expression. The expression of GARP-G2-like and C3H transcription factors was specifically modulated by As(V) stress. The predominant families of As(V)-regulated transporters belonged to the ATP-binding cassette superfamily and telurite-resistance/dicarboxylate transporters. Several factors involved in signaling, such as mitogen-activated protein kinase (MAPK), MAPK kinase kinase and calcium-dependent protein kinase (CDPK), were also upregulated. Moreover, As(V) markedly increased the activity of MAPKs and CDPK-like kinases, and CDPK and NADPH oxidases were involved in As-induced MAPK activation. Further characterization of these As(V)-responsive genes and signalling pathways may help better understand the mechanisms of metalloid uptake, tolerance and detoxification in plants.

Genome-Wide Transcriptome Analysis Reveals that Cadmium Stress Signaling Controls the Expression of Genes in Drought Stress Signal Pathways in Rice

“…In particular, GSTU12 (shoot), GSTU19 (root and shoot), GSTU24 (root and shoot), GSTU30 (shoot), GSTU31 (root) and GSTU39 (root) were strongly upregulated [fold change (FC) > 20] (Figure 4A). GSTU19 , GSTU24 and GSTU39 were found to be upregulated in the roots of rice seedlings under arsenate exposure using a microarray platform [67], suggesting that part of the Cd defense might be similar to the As defense in the roots of rice. Enhanced GST with glutathione peroxidase activity in transgenic tobacco increased glutathione-dependent peroxide scavenging and alterations in glutathione and ascorbate metabolism that led to reduced oxidative damage [68].…”

Genomic Responses to Arsenic in the Cyanobacterium Synechocystis sp. PCC 6803

“…Sulfur metabolism genes have been shown to be induced after arsenic treatments in bacteria [58], [65], yeast [44], [51], [66] and plants [63], [67], [68]. These genes include sulfate transport, sulfur assimilation and cysteine synthesis genes, which are needed in order to increase GSH contents.…”

Decrypting Calcium Signaling in Plants: The Kinase Way

“…A genome-wide transcript abundance study of grape ( Vitis vinifera L.) leaves under heat stress revealed upregulation of one CDPK (CF511469) and CIPK25 gene (BQ797947; Liu et al 2012 ). In another study, large-scale ESTs of abiotic stresstreated leaves, berries, and root of Vitis vinifera were generated and analyzed where transcripts encoding for CIPK10 were overrepresented in both the stressed leaf and berries clusters (Tillett et al 2011). Huang et al ( 2012 performed microarray study of early Arsenic-induced gene expression in rice and showed that along with seven calmodulin genes, two CBL genes, one CIPK gene ( OsCIPK21 ), and four CDPK genes ( OsCPK4, OsCPK13, OsCPK20 , and OsCPK21 ) were upregulated on As(V) treatment.…”