Exposure to Low UV-B Dose Induces DNA Double-Strand Breaks Mediated Onset of Endoreduplication in Vigna radiata (L.) R. Wilczek Seedlings

Abstract

Multiple lines of evidence indicate that solar UV-B light acts as an important environmental signal in plants, regulating various cellular and metabolic activities, gene expression, growth, and development. Here, we show that low levels of UV-B (4.0 kJ m-2) significantly influences plant response during early seedling development in the tropical legume crop Vigna radiata (L.) R. Wilczek. Exposure to low doses of UV-B showed relatively less growth inhibition, yet remarkably enhanced lateral root formation in seedlings. Both low and high (8.0 kJ m-2) doses of UV-B treatment induced DNA double strand breaks (DSBs) and activated the SOG1-related ATM-ATR mediated DNA damage response pathway. These effects led to G2-M-phase arrest with a compromised expression of the key cell cycle regulators, including CDKB1;1, CDKB2;1, and CYCB1;1, respectively. However, along with these effects, imbibitional exposure of seeds to a low UV-B dose resulted in enhanced accumulation of FZR1/CCS52A, E2Fa and WEE1 kinase and prominent induction of endoreduplication in 7-day-old seedlings. Low dose of UV-B mediated phenotypical responses, while the onset of endoreduplication appeared to be regulated at least in part via UV-B induced ROS accumulation. Transcriptome analyses further revealed a network of co-regulated genes associated with DNA repair, cell cycle regulation and oxidative stress response pathways that are activated upon exposure to low doses of UV-B.

Melatonin induces endoreduplication through oxidative DNA-damage triggering lateral root formation in onions

“…It is already evident that Mel can induce lateral roots in plants with different effective concentrations(Ren et al, 2019) through ROS signalling, where H 2 O 2 serves as a signalling molecule to activate down-stream ROS/Ca 2+ signalling pathway(Chen et al, 2019;Bian et al, 2021). In this study, we have shown the connecting link between ROS-induced DNA-damage, endoreduplication and lateral root formation De et al, (2022). reported that the treatment of Vigna radiate with a low dose (4.0 kJ m −2 ) of UV-B is coupled with a retarded primary root growth and an increased number of lateral roots, whereas, reduced primary root growth and lateral root numbers had been observed in high dose (8.0 kJ m −2 ) group.…”

“…Regarding lateral root formation, Davis et al, (2016) reported the inhibition of lateral roots in Arabidopsis by DNA-damage causing the up-regulation of cytokinin biosynthesis genes. Conversely, De et al, (2022) showed an enhanced level of lateral root formation in Vigna radiata after exposure to the low dose of UV-B for a longer period. Two possibilities may come out from these studies: firstly, lateral root development under DNA-damage stress varies with plant species, and secondly, it is the extent of DNA-damage that decides whether lateral root will develop or not.…”

Genome-wide identification, evolutionary and expression analysis of the cyclin-dependent kinase gene family in peanut

“…For instance, the mammalian genome encodes nearly 20 CDKs, whereas in yeast there are only six [ 6 ]. Despite its role in cell cycle progression, CDKs are also involved in DNA repair, transcriptional regulation, and proteolytic degradation mechanisms in mammals [ 7 , 8 ].…”

Ultraviolet attenuates centromere-mediated meiotic genome stability and alters gametophytic ploidy consistency in flowering plants

“…Exposure to UV radiation is unavoidable for plants when capturing sunlight for photosynthesis. UV affects many development processes in plants, such as endoreduplication, hypocotyl and cotyledon development, flavonoid accumulation, and DNA stability (De et al, 2022; Li et al, 2013; Ries et al, 2000; Shi and Liu, 2021; Verdaguer et al, 2017). In addition, UV influences plant development by inducing reactive oxygen species (ROS) and antioxidants (Gill et al, 2015; Sinha and Häder, 2002).…”