Different expression of miRNAs targeting helicases in rice in response to low and high dose rate γ-ray treatments

Abstract

Ionizing radiation currently represents an important tool to generate genetic variability that does not exist in nature, especially in plants. Even so, the radiological protection still represents a subject of regulatory concern. In plants, few reports dealing with the effects of γ-rays, in terms of dose rate (rate of energy deposition) and total dose (energy absorbed per unit mass), are available. In addition, plants are known to be more radioresistant than animals. The use of ionizing radiations for studying various aspects of transcription regulation may help elucidate some of the unanswered questions regarding DNA repair in plants. Under these premises, microRNAs have emerged as molecules involved in gene regulation in response to various environmental conditions as well as in other aspects of plant development. Currently, no report on the changes in microRNAs expression patterns in response to γ-ray treatments exists in plants, even if this subject is extensively studies in human cells. The present study deals with the expression profiles of three miRNAs, namely osa-miR414, osa-miR164e and osa-miR408 and their targeted helicase genes (OsABP, OsDBH and OsDSHCT) in response to different doses of γ-rays delivered both at low and high dose rates. The irradiated rice seeds were grown both in the presence of water and 100 mM NaCl solution. DNA damage and reactive species accumulation were registered, but no dose- or time-dependent expression was observed in response to these treatments.

Drought Response in Rice: The miRNA Story

“…In an in silico study conducted by Umate and Tuteja (2010), 12 miRNAs that targeted helicase genes in rice were identified [140]. Out of these 12, miR164, miR408, and miR414 were down regulated and known to affect DEAD-box helicases (DBH) that play a role in up regulating the response to drought and salinity stress in plants [141]. miR156, miR159, and miR396 are highly regulated in Arabidopsis however the same miRNAs are severely down regulated in rice [33].…”

Long term effects of Chernobyl contamination on DNA repair function and plant resistance to different biotic and abiotic stress factors

“…Significant fluctuations in accumulation and repair of DSBs were observed between HDR (5.15 Gy min −1 ) and LDR (0.33 Gy min −1 ) treatments in the 0-4 h time period following irradiation [74]. Finally, differential expression of miRNA regulating expression of some DNA repair genes was found in response to low and high dose-rate gamma-ray exposure of rice plants [79].…”

Redox Balance-DDR-miRNA Triangle: Relevance in Genome Stability and Stress Responses in Plants

“…Of these, osa-MIR414, osa-MIR408 and osa-MIR164e have been experimentally validated as targeting the OsABP (ATP-Binding Protein), OsDSHCT (DOB1/SK12/helY-like DEAD-box Helicase), and OsDBH (DEAD-Box Helicase) genes (Macovei and Tuteja, 2012). The expression of miRNAs and their targeted genes correlated negatively in response to salinity stress and gamma-irradiation treatments, which caused DNA, damage (Macovei and Tuteja, 2012, 2013). Given that helicases are enzymes that catalyze the separation of double-stranded nucleic acids in an energy-dependent manner, they are involved in a wide range of processes such as recombination, replication and translation initiation, double-strand break repair, maintenance of telomere length, nucleotide excision repair, and cell division and proliferation (Tuteja, 2003).…”