Figure 3. Tradeoffs when adopting stress-protected states.

(A) Growth rate and population size under stress (duration ) and subsequent regrowth. A population that maintains the active state and remains vegetative upon stress exposure (, full green line) dies at the maximal rate (top panel) and can resume the maximal growth rate after a minimal growth lag when the environment improves at . Despite resuming growth with a ten fold lower number of stress-surviving cells, it can outgrow a second population which adopted a stress-protected state (, red dashed line) that provides enhanced stress survival but requires a significantly longer lag time . (B) Environmental regimes of stress and growth durations () where the stress-resistant (red) or the remaining-active population (green) are more competitive, separated by the black phase boundary . When the typical environment is characterized by frequent but short stress periods, populations can benefit from remaining vegetative upon stress, delaying the protected state, and thereby avoiding growth-retardation after stress. However, the active population also needs a minimal growth duration to reestablish the part of the population that was lost during stress, note the curved phase boundary. Above a maximal stress duration, given by the phase boundary, the loss in viable cells of the vegetative population during stress becomes too large; it cannot reestablish the initial population size before the stress-protected population resumes growth.