Increased tolerance to Phytophthora cinnamomi in offspring of ink-diseased chestnut (Castanea sativa Miller) trees

Abstract

& Key message Increased tolerance to Phytophthora cinnamomi was observed in small-sized offspring of ink-diseased chestnut trees, suggesting that a virulent pathogen can trigger a defence response of trees in the subsequent generation. Increased tolerance to water stress was not observed in offspring of chestnut trees. & Context In sweet chestnut (Castanea sativa Miller), P. cinnamomi Rands is responsible for the widespread and destructive ink disease. & Aims We investigated if the susceptibility of C. sativa to water stress and P. cinnamomi depends on the health status of mother trees. & Methods Plants were grown from seeds collected from healthy and ink-diseased chestnut trees. Leaf wilting after drought exposure and plant mortality after pathogen inoculation were assessed. & Results Offspring of ink-diseased trees had poorer performance in plant height and root biomass than offspring of healthy trees, with allocation of biomass to seeds mediating this effect. Leaf wilting due to water stress was similar in offspring of healthy and P. cinnamomi-infected trees. However, increased tolerance to P. cinnamomi was observed in small-sized seedlings, suggesting that tolerance in C. sativa may involve growth costs. This is the first report of increased tolerance to P. cinnamomi in plants germinating from a diseased tree. & Conclusion The results suggest that an invasive pathogen can regulate the performance and prime a defence response of a forest tree species in the subsequent generation, and generate conflicting selection pressures related to plant size.

Invasive forest pathogens affect the characteristics, microbial colonisation, and decomposition of leaf litter in streams

“…This riparian forest has a Mediterranean climate, with mean air temperature of 14.9°C and mean annual precipitation of 1005 mm. Isolations of P. cinnamomi from the rhizosphere of symptomatic trees suggested that they were infected, whereas no P. cinnamomi was isolated from the rhizosphere of healthy trees (Camisón et al., 2019). Healthy and declining alders were located along the river Jerte, Plasencia, Spain (40°01′51.2″N 6°04′46.0″W; 329 m a.s.l.…”

Advances and Promises of Epigenetics for Forest Trees

“…The influence of the maternal environment has also been shown to play an important role in the tolerance level of the offspring to various pathogens. Individuals from mother plants exposed to pathogens appear to be more tolerant to these same pathogens, and authors hypothesized that epigenetic mechanisms may be involved in this priming phenomenon [149,150]. Recently, Lamelas et al (2020) [151] proposed the importance of epigenetic mechanisms for P. radiata heat stress tolerance and priming by evaluating the nuclear proteome and tissue DNA methylation dynamics of seedlings submitted to 45 • C for 10 days, allowed to recover, and submitted to another stress cycle.…”

Effect of elicitors on holm oak somatic embryo development and efficacy inducing tolerance to Phytophthora cinnamomi

“…Environmental maternal effects on the tolerance of Pinus pinaster to biotic stress have been reported 32 . In addition, a recent work 35 , demonstrated that chestnut (Castanea sativa) seedlings of ink-diseased mother trees showed increased tolerance to P. cinnamomi; interestingly, this tolerance was not mediated by seed size, but probably as a consequence of seed priming during fruit development. These inheritable variations could open doors for obtaining resistant or tolerant oak genotypes, which would be included in a recovery program in damaged areas, avoiding oak woodlands and dehesa dieback.…”