DNA Damage and Repair in Plants under Ultraviolet and Ionizing Radiations

Abstract

Being sessile, plants are continuously exposed to DNA-damaging agents present in the environment such as ultraviolet (UV) and ionizing radiations (IR). Sunlight acts as an energy source for photosynthetic plants; hence, avoidance of UV radiations (namely, UV-A, 315–400 nm; UV-B, 280–315 nm; and UV-C, <280 nm) is unpreventable. DNA in particular strongly absorbs UV-B; therefore, it is the most important target for UV-B induced damage. On the other hand, IR causes water radiolysis, which generates highly reactive hydroxyl radicals (OH•) and causes radiogenic damage to important cellular components. However, to maintain genomic integrity under UV/IR exposure, plants make use of several DNA repair mechanisms. In the light of recent breakthrough, the current minireview (a) introduces UV/IR and overviews UV/IR-mediated DNA damage products and (b) critically discusses the biochemistry and genetics of major pathways responsible for the repair of UV/IR-accrued DNA damage. The outcome of the discussion may be helpful in devising future research in the current context.

Characterization of microRNAs and their target genes associated with transcriptomic changes in gamma-irradiated Arabidopsis

“…Biological effects of ionizing radiation, which acts as a genotoxic agent and oxidative stress inducer, are often compared with those of H 2 O 2 or UV-B radiation (Nagata et al, 2005;Moon et al, 2008;Simone et al, 2009;Gill et al, 2015). For comparison, we performed a literature search to investigate what miRNAs respond to H 2 O 2 or UV-B radiation as well as ionizing radiation (Table 1); however, only a few articles could be identified.…”

High-Throughput Robotically Assisted Isolation of Temperature-sensitive Lethal Mutants in <em>Chlamydomonas reinhardtii</em>

“…1. In order to ensure maximum potency of UV irradiation with no reversion due to light-dependent DNA repair 11,12 , work in the dark at this step and immediately pack the plates in a dark box after irradiation.…”

Role of He-Ne laser pre-treatment in protecting Zea mays against the deleterious effects of ultraviolet radiations

“…Ultraviolet radiati ons (UV) ar e a nonionizing el ectrom agnetic spectr um t hat embraces about 8-9% of s ol ar energ y (Gill et al, 2015). O zone depleti on in the strat osphere has r esult ed in an increm ent i n ultravi olet-B irradiati on (UV-B ; 280-320 nm), which has pot entiall y destr uctiv e consequences for crop yield and production and aff ect nat ural environm ents (J ulkunenTiitto et al, 2005;Siipola et al ., 2015).…”

“…Enhanc ed levels of ultravi olet r adiations trigger different str uct ural, p hysiol ogical and molec ular resp ons es i n plant s (Cas ati, 2003; Kum ari et al , 2009; Sal ama et al , 2011;Gill et al , 2015). A higher d ose of UV-B prov ok es impairment and modific ation of macrom olec ules like DNA , RN A, and prot eins , decreas e net phot os ynthesis and adjust the activities of sev eral antioxidant enz ym es (Gill and T ut eja, 2010;Sharma et al, 2012).…”