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Kinetics of DNA Repair in Vicia faba Meristem Regeneration Following Replication Stress. Cells 2021; 10:cells10010088. [PMID: 33430297 PMCID: PMC7825715 DOI: 10.3390/cells10010088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/29/2020] [Accepted: 01/04/2021] [Indexed: 12/14/2022] Open
Abstract
The astonishing survival abilities of Vicia faba, one the earliest domesticated plants, are associated, among other things, to the highly effective replication stress response system which ensures smooth cell division and proper preservation of genomic information. The most crucial pathway here seems to be the ataxia telangiectasia-mutated kinase (ATM)/ataxia telangiectasia and Rad3-related kinase (ATR)-dependent replication stress response mechanism, also present in humans. In this article, we attempted to take an in-depth look at the dynamics of regeneration from the effects of replication inhibition and cell cycle checkpoint overriding causing premature chromosome condensation (PCC) in terms of DNA damage repair and changes in replication dynamics. We were able to distinguish a unique behavior of replication factors at the very start of the regeneration process in the PCC-induced cells. We extended the experiment and decided to profile the changes in replication on the level of a single replication cluster of heterochromatin (both alone and with regard to its position in the nucleus), including the mathematical profiling of the size, activity and shape. The results obtained during these experiments led us to the conclusion that even “chaotic” events are dealt with in a proper degree of order.
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Kantharaj V, Ramasamy NK, Yoon YE, Cheong MS, Kim YN, Lee KA, Kumar V, Choe H, Kim SY, Chohra H, Lee YB. Auxin-Glucose Conjugation Protects the Rice ( Oryza sativa L.) Seedlings Against Hydroxyurea-Induced Phytotoxicity by Activating UDP-Glucosyltransferase Enzyme. FRONTIERS IN PLANT SCIENCE 2021; 12:767044. [PMID: 35251058 PMCID: PMC8888425 DOI: 10.3389/fpls.2021.767044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 12/27/2021] [Indexed: 05/02/2023]
Abstract
Hydroxyurea (HU) is the replication stress known to carry out cell cycle arrest by inhibiting ribonucleotide reductase (RNR) enzyme upon generating excess hydrogen peroxide (H2O2) in plants. Phytohormones undergo synergistic and antagonistic interactions with reactive oxygen species (ROS) and redox signaling to protect plants against biotic and abiotic stress. Therefore, in this study, we investigated the protective role of Indole-3-acetic acid (IAA) in mitigating HU-induced toxicity in rice seedlings. The results showed that IAA augmentation improved the growth of the seedlings and biomass production by maintaining photosynthesis metabolism under HU stress. This was associated with reduced H2O2 and malondialdehyde (MDA) contents and improved antioxidant enzyme [superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and peroxidase (POD)] activity that was significantly affected under HU stress. Furthermore, we showed that the HU stress-induced DNA damage leads to the activation of uridine 5'-diphosphate-glucosyltransferase (UGT), which mediates auxin homeostasis by catalyzing IAA-glucose conjugation in rice. This IAA-glucose conjugation upregulates the RNR, transcription factor 2 (E2F2), cyclin-dependent kinase (CDK), and cyclin (CYC) genes that are vital for DNA replication and cell division. As a result, perturbed IAA homeostasis significantly enhanced the key phytohormones, such as abscisic acid (ABA), salicylic acid (SA), cytokinin (CTK), and gibberellic acid (GA), that alter plant architecture by improving growth and development. Collectively, our results contribute to a better understanding of the physiological and molecular mechanisms underpinning improved growth following the HU + IAA combination, activated by phytohormone and ROS crosstalk upon hormone conjugation via UGT.
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Affiliation(s)
- Vimalraj Kantharaj
- Division of Applied Life Science (BK 21 Four), Gyeongsang National University, Jinju, South Korea
| | | | - Young-Eun Yoon
- Division of Applied Life Science (BK 21 Four), Gyeongsang National University, Jinju, South Korea
| | - Mi Sun Cheong
- Institute of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju, South Korea
| | - Young-Nam Kim
- Institute of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju, South Korea
| | - Keum-Ah Lee
- Department of Smart Agro-Industry, Gyeongsang National University, Jinju, South Korea
| | - Vikranth Kumar
- Division of Plant Sciences, University of Missouri, Columbia, MO, United States
| | - Hyeonji Choe
- Division of Applied Life Science (BK 21 Four), Gyeongsang National University, Jinju, South Korea
| | - Song Yeob Kim
- Division of Applied Life Science (BK 21 Four), Gyeongsang National University, Jinju, South Korea
| | - Hadjer Chohra
- Division of Applied Life Science (BK 21 Four), Gyeongsang National University, Jinju, South Korea
| | - Yong Bok Lee
- Division of Applied Life Science (BK 21 Four), Gyeongsang National University, Jinju, South Korea
- *Correspondence: Yong Bok Lee,
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