Abstract
Lichens and mosses often share the same environmental conditions where they compete for substrate and other essential factors. Lichens use secondary metabolites as allelochemicals to repel surrounding plants and potential rivals. In mosses, endoreduplication leads to the occurrence of various ploidy levels in the same individual and has been suggested as an adaptation to abiotic stresses. Here, we show that also biotic factors such as usnic acid, an allelochemical produced by lichens, directly influenced the level of ploidy in mosses. Application of usnic acid changed the nuclei proportion and significantly enhanced the endoreduplication index in two moss species, Physcomitrella patens and Pohlia drummondii. These investigations add a new aspect on secondary metabolites of lichens which count as biotic factors and affect ploidy levels in mosses.
Highlights
The pattern of endopolyploidy was presented as (1) number of peaks appearing in flow cytometry (FCM) histograms, which indicate the presence of nuclei with different ploidy levels in each measured sample and by (2) endoreduplication index (EI) representing the degree of endopolyploidy
We demonstrated that lichen compounds influenced the level of endopolyploidy in mosses
We confirm the occurrence of endopolyploidization in two additional moss species P. patens and P. drummondii, supplementary to 46 bryophyte species previously tested by Bainard and Newmaster (2010)
Summary
Moss plantlets of two species, P. patens (Hedw.) Bruch & Schimp. and P. drummondii Each fiber disk was photographed after 5 weeks and the area occupied by plant material was measured. The pattern of endopolyploidy was presented as (1) number of peaks appearing in flow cytometry (FCM) histograms, which indicate the presence of nuclei with different ploidy levels in each measured sample and by (2) endoreduplication index (EI) representing the degree of endopolyploidy. The growth area experiment was performed on sterile solid media, with homogenized moss material of the two species growing on fiber disks. Growth area measurements (Figure 2) confirmed that P. patens was not affected by UA treatments while P. drummondii is much more sensitive to 0.1 mg/ disk UA. In gametophyte of P. drummondii, flow cytometry measurements detected three peaks on FCM histograms (Figure 3b,d) which correspond to 1C, 2C, and 4C nuclei. The EI of P. drummondii was higher than in P. patens
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
