Figure 1

From: Microbial contributions to the persistence of coral reefs

Figure 1

Conceptual overview of the microbial mechanisms facilitating transgenerational acclimatisation of coral reef organisms. Under elevated seawater temperature and pCO2, specific host-associated microorganisms may increase or decrease in abundance, thereby altering holobiont function and fitness. These frequency shifts can occur in the Symbiodinium (large circular cells differentially shaded according to clade) or prokaryotic community (rod-shaped cells). Shifts in community composition can also occur via acquisition of new microorganisms from the surrounding environment. In addition, mutation and/or horizontal gene transfer can introduce new genetic material into existing symbiont populations (white cells with black inset). This process can occur in any component (Symbiodinium, bacteria, archaea) of the host microbiome. If microbial alterations that infer a fitness advantage to the host are vertically transmitted to the offspring (denoted by sketch of a newly settled coral recruit), transgenerational acclimatisation can occur.