Trade-Offs between Competitive Ability and Resistance to Top-Down Control in Marine Microbes
Journal
mSystems
Journal Volume
8
Journal Issue
2
Date Issued
2023-04-01
Author(s)
Yang, Jinny Wu
Yeh, Yi Chun
Tsai, An Yi
Chiang, Kuo Ping
Shiah, Fuh Kwo
Gong, Gwo Ching
Abstract
Trade-offs between competitive ability and resistance to top-down control manifest the “kill-the-winner” hypothesis that explains how mortality caused by protists and viruses can promote bacterial diversity. However, the existence of such trade-offs has rarely been investigated in natural marine bacterial communities. To address this question, we conducted on-board dilution experiments to manipulate top-down control pressure (protists only or protists plus viruses [protists1viruses] combined) and then applied 16S rRNA gene high-throughput sequencing techniques to assess the responses of each bacterial taxon. Dilution experiments enabled us to measure the top-down-control-free growth rate as the competitive ability and top-down-control-caused mortality as the reverse of resistance to top-down control. Overall, bacterial taxa with higher top-down-control-free growth rates were accompanied by lower top-down-control-caused resistance. Furthermore, competition-resistance trade-offs were stronger and more consistent when top-down control was caused by protists1viruses combined than by protists only. When protists1viruses were diluted, the bacterial rank abundance distribution became steepened and evenness and richness were decreased. However, when protists were diluted, only richness decreased. Our results indicate the existence of competition-resistance trade-offs in marine microbes and demonstrate the positive impacts of such trade-offs on bacterial diversity. Regardless, the strength of the competition-resistance trade-offs and the impacts on bacterial diversity were contingent on whether top-down control was caused by protists1viruses combined or protists only.
Subjects
dilution experiments
high-throughput sequencing
kill-the-winner hypothesis
marine bacterial communities
top-down controls
SDGs
Type
journal article