Title: | UVB Radiation Suppresses Antigrazer Morphological Defense in Scenedesmus obliquus by Inhibiting Algal Growth and Carbohydrate-Regulated Gene Expression |
Author(s): | Sun Y; Zhang X; Zhang L; Huang Y; Yang Z; Montagnes D; |
Address: | "Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China. Institute of Integrative Biology, Biosciences Building, University of Liverpool, Liverpool L69 7ZB, U.K" |
ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
Abstract: | "Solar ultraviolet-B (UVB) radiation reaching the earth's surface is increasing due to stratospheric ozone depletion. How the elevated UVB affects the trophic interactions is critical for predicting the ecosystem functioning under this global-scale stressor. Usually, inducible defenses in phytoplankton stabilize community dynamics within aquatic environments. To assess the effects of elevated UVB on induced defense, we examined the changes in antigrazer colony formation in Scenedesmus obliquus under environmentally relevant UVB. S. obliquus exposed to Daphnia infochemicals consistently formed multicelled colonies, traits confirmed to be adaptive under predation risk. However, the suppressed photochemical activity and the metabolic cost from colony formation resulted in the severer reductions in algal growth by UVB under predation risk. The transcriptions of key enzyme-encoding genes, regulating the precursor synthesis during polysaccharide production, were also inhibited by UVB. Combination of the reduced production of daughter cells and the ability of daughter cells to remain attached, the antigrazing colony formation was interrupted, leading to the dominant morphs of algal population shifting from larger-sized colonies to smaller ones at raised UVB. The present study revealed that elevated UVB will not only reduce the phytoplankton growth but also increase their vulnerability to predation, probably leading to potential shifts in plankton food webs" |
Keywords: | Animals Carbohydrates Daphnia Ecosystem *Scenedesmus Ultraviolet Rays; |
Notes: | "MedlineSun, Yunfei Zhang, Xingxing Zhang, Lu Huang, Yuan Yang, Zhou Montagnes, David eng Research Support, Non-U.S. Gov't 2020/02/29 Environ Sci Technol. 2020 Apr 7; 54(7):4495-4503. doi: 10.1021/acs.est.0c00104. Epub 2020 Mar 10" |