Endopolyploidy is a common response to UV-B stress in natural plant populations, but its magnitude may be affected by chromosome type. (25th June 2020)

• Record Type: Journal Article
• Authors: Zedek, František; Plačková, Klára; Veselý, Pavel; Šmerda, Jakub; Šmarda, Petr; Horová, Lucie; Bureš, Petr
• Is Part Of: Annals of botany. Volume 126:Number 5(2020)
• Page Start: 883
• Page End: 889
• Publication Date: 2020-06-25
• Subjects: Endopolyploidy -- endoreduplication index -- flow cytometry -- holocentric chromosomes -- monocentric chromosomes -- natural population -- ultraviolet radiation -- UV-B-absorbing compounds; Botany -- Periodicals; 580
• DOI: 10.1093/aob/mcaa109
• Languages: English
• ISSNs: 0305-7364

Abstract

Abstract: Background and Aims: Ultraviolet-B radiation (UV-B) radiation damages the DNA, cells and photosynthetic apparatus of plants. Plants commonly prevent this damage by synthetizing UV-B-protective compounds. Recent laboratory experiments in Arabidopsis and cucumber have indicated that plants can also respond to UV-B stress with endopolyploidy. Here we test the generality of this response in natural plant populations, considering their monocentric or holocentric chromosomal structure. Methods: We measured the endopolyploidy index (flow cytometry) and the concentration of UV-B-protective compounds in leaves of 12 herbaceous species (1007 individuals) from forest interiors and neighbouring clearings where they were exposed to increased UV-B radiation (103 forest + clearing populations). We then analysed the data using phylogenetic mixed models. Key Results: The concentration of UV-B protectives increased with UV-B doses estimated from hemispheric photographs of the sky above sample collection sites, but the increase was more rapid in species with monocentric chromosomes. Endopolyploidy index increased with UV-B doses and with concentrations of UV-B-absorbing compounds only in species with monocentric chromosomes, while holocentric species responded negligibly. Conclusions: Endopolyploidy seems to be a common response to increased UV-B in monocentric plants. Low sensitivity to UV-B in holocentric species might relate to their success in high-UV-stressed habitats and corroborates the hypothesized role of holocentric chromosomes in plant terrestrialization.