Effect of maternal infection on progeny growth and resistance mediated by maternal genotype and nutrient availability

1. Maternal effects of pathogen infection on progeny development
and disease resistance may be adaptive and have important consequences for
population dynamics. However, these effects are often context dependent
and examples of adaptive transgenerational responses from perennials are
scarce, although they may be a particularly important mechanism generating
variation in the offspring of long-lived species. 2. Here, we
studied the effect of maternal infection of Plantago lanceolata by
Podosphaera plantaginis, a fungal parasite, on the growth, flower
production and resistance of the progeny of six maternal genotypes in
nutrient rich and poor environments. For this purpose, we combined a
common garden study with automated phenotyping measurements of early
life-stages, and an inoculation experiment. 3. Our results show that the
effects of infection on the mother plants transcend to impact their
progeny. Although maternal infection decreased total leaf and flower
production of the progeny by the end of the growing season, it accelerated
early growth and enhanced resistance to the pathogen P. plantaginis.
4. We also discovered that the effects of maternal infection
affected progeny development and resistance both directly, and through a
three way-interaction between maternal genotype, maternal infection status
and nutrient availability.   5. Synthesis: Our results emphasize
the importance of maternal effects mediated through genotypic and
environmental factors in long living perennials and suggest that maternal
infection can create a layer of phenotypic diversity in resistance. These
results may have important implications for both epidemiological and
evolutionary dynamics of host–parasite interactions in the wild.