Molecular Identification and Analysis of Cd-Responsive MicroRNAs in Rice

Abstract

Cadmium (Cd) is a non-essential heavy metal with high toxicity to plants. MicroRNAs (miRNAs) are a class of small non-coding RNAs that play important roles in plant abiotic stress responses. To investigate whether miRNAs function in Cd stress response, miRNA expression profiles in rice ( Oryza sativa ) under Cd stress were monitored using microarray assays. A total of 12 Cd-responsive novel miRNAs predicted previously were identified, of which 4 were further validated experimentally. A total of 44 target genes were predicted for the Cd-responsive miRNAs, many of which appeared to regulate gene networks mediating environmental stresses. Several target genes were validated to show a reciprocal regulation by miRNAs. A transgenic approach was also used to determine the role of miRNAs in rice response to Cd stress. Overexpression of miR192 retarded seed germination and seedling growth under Cd stress. These results implied the role of novel miRNAs in the involvement of Cd tolerance of rice.

Identification of Radish (Raphanus sativus L.) miRNAs and Their Target Genes to Explore miRNA-Mediated Regulatory Networks in Lead (Pb) Stress Responses by High-Throughput Sequencing and Degradome Analysis

“…miRNAs regulate gene expression mainly at the posttranscriptional level. Recently, a group of miRNAs and their targets have been identified in respond to metal stresses in plants, and increasing evidence has revealed that miRNAmediated gene regulation plays a significant role in HM regulatory networks (Chen et al 2012;Ding et al 2013;Khraiwesh et al 2012;Zhou et al 2012). These studies focused on certain types of HMs including cadmium (Cd), mercury (Hg), arsenic (As) and aluminum (Al); however, the identification of Pb-regulated miRNAs and their target genes have not yet been reported in plants.…”

“…When complete radish genome sequence data becomes available, more radish miRNAs will be obtained (Ambady et al 2012). Many miRNAs have been identified in response to HMs (e.g., Cd, Hg, As, and Al) in rice (Ding et al 2013), M. truncatula (Zhou et al 2012), B. juncea (Srivastava et al 2013) and soybean , which provided a means of exploring the molecular basis for metal adaptive responses in plants (Gielen et al 2012;Gupta et al 2014;Khraiwesh et al 2012;Yang and Chen 2013). In the current study, a total of 25 known and nine novel miRNAs were significantly differentially expressed and identified as Pb-responsive miRNAs (Table 4).…”

Effects of nitric oxide on alleviating cadmium stress in Typha angustifolia

“…Thus, with regards to agricultural plants growing in these affected areas, the sustentative consumption of high-Cd plant tissue constitutes a significant threat to human health (Wang et al 2013;Wu et al 2014). As a non-essential nutrient, Cd has been shown to influence the absorption, transportation, and usage of both water and essential nutrients while also causing various visible symptoms including chlorosis, wilting and root browning (Ding et al 2013;Gallego et al 2012;Garcia et al 2006;Gratao et al 2012). To cope with Cd stress, plants adopt many ways to avoid Cd stress or enhance tolerance to Cd toxicity (Baker 1987).…”

Analysis of Signaling Pathways During Heavy Metal Toxicity: A Functional Genomics Perspective

“…Thus, the present trend in cadmium stress biology is to use large-scale genomic data to scrutinize and revalidate the osmolyte biosynthesis, antioxidants, LEA proteins, molecular chaperones, cell membrane proteins, aquaporins and transporters, ion homeostasis, and transcription factors involved in Cd stress tolerance based on transgenic (overexpression and insertional inactivation) approaches (Sreenivasulu et al 2007 ). In addition to overexpression and insertional inactivation, another group of tools known as "RNA interference (RNAi)" is quite promising on the depiction of gene to function assignment of complex biological processes even in the regulation/signaling of heavy metal stress response (Jones-Rhoades et al 2006 ;Mendoza-Soto et al 2012 ;Ding et al 2013 ). Among the RNAi tools, microRNAs (miRNAs) are a group of endogenous non-protein-coding small RNAs of 21 nucleotides.…”

“…These miRNAs negatively regulate the post-transcriptional processes and translation of specifi c mRNA targets through RNA-induced silencing complex (RISC) in cells ( Bartel 2004 ). Majority of miRNAs are conserved across the species making it possible to identify putative miRNAs in other species using comparative genomics (Ding et al 2013 ). Recently, it has been reported that miRNAs act as crucial regulators of multiple physiological processes, including plant development, signal transduction, and adaption to heavy metal stresses (Sunkar et al 2006 ;Zhou et al 2008Zhou et al , 2012Huang et al 2009 ;Mendoza-Soto et al 2012 ;Hartwig 1995, Jagadeesan et al 2010.…”