Potential Maternal Effects of Elevated Atmospheric CO2 on Development and Disease Severity in a Mediterranean Legume

Abstract

Global change can greatly affect plant populations both directly by influencing growing conditions and indirectly by maternal effects on development of offspring. More information is needed on transgenerational effects of global change on plants and their interactions with pathogens. The current study assessed potential maternal effects of atmospheric CO2 enrichment on performance and disease susceptibility of first-generation offspring of the Mediterranean legume Onobrychis crista-galli. Mother plants were grown at three CO2 concentrations, and the study focused on their offspring that were raised under common ambient climate and CO2. In addition, progeny were exposed to natural infection by the fungal pathogen powdery mildew. In one out of 3 years, offspring of high-CO2 treatments (440 and 600 ppm) had lower shoot biomass and reproductive output than offspring of low-CO2 treatment (280 ppm). Disease severity in a heavy-infection year was higher in high-CO2 than in low-CO2 offspring. However, some of the findings on maternal effects changed when the population was divided into two functionally diverging plant types distinguishable by flower color (pink, Type P; white, Type W). Disease severity in a heavy-infection year was higher in high-CO2 than in low-CO2 progeny in the more disease-resistant (Type P), but not in the more susceptible plant type (Type W). In a low-infection year, maternal CO2 treatments did not differ in disease severity. Mother plants of Type P exposed to low CO2 produced larger seeds than all other combinations of CO2 and plant type, which might contribute to higher offspring performance. This study showed that elevated CO2 potentially exerts environmental maternal effects on performance of progeny and, notably, also on their susceptibility to natural infection by a pathogen. Maternal effects of global change might differently affect functionally divergent plant types, which could impact population fitness and alter plant communities.

Seed germination and rising atmospheric CO2 concentration: a meta‐analysis of parental and direct effects

“…A number of studies have indicated that genotypic (Wulff & Alexander, ; Curtis et al ., ; Ward & Strain, ; Andalo et al ., ; Bai et al ., ) and species‐specific (Farnsworth & Bazzaz, ; Jablonski et al ., ) differences interact with parental CO 2 concentrations to determine reproductive quality and/or outputs. The limited research also suggests that both female (Garbutt & Bazzaz, ; Jablonski et al ., ; Grünzweig, ) and male (Prasad et al ., ; Marshall et al ., ) components of reproductive fitness can be influenced by e CO 2 . However, the relative contribution of maternal vs paternal traits regulating seed germination responses to e CO 2 is still unknown.…”

Effect of Elevated Atmospheric CO2 and Temperature Increases on the Severity of Basil Downy Mildew Caused by Peronospora belbahrii Under Phytotron Conditions

“…For example, von Tiedemann and Firsching () found that nitrogen‐fixing legumes were more sensitive to elevated CO 2 and consequently to disease, while elevated CO 2 did not affect the leaf rust disease of wheat. Grünzweig () showed that high CO 2 could affect the susceptibility of Onobrychis crista‐galli to powdery mildew. In other cases, it has been shown that elevated CO 2 did not influence the disease of zucchini powdery mildew (Pugliese et al.…”

“…It is impossible to achieve such a degree of control under natural field conditions. Over the last decade, phytotrons have been used to study the effects of CO 2 enrichment and temperature increases on infection rates for several pathosystems (Ainsworth and Long 2005;Chakraborty 2005;Garrett et al 2006;Gr€ unzweig 2011;Pugliese et al 2012a,b;Ferrocino et al 2013;Singh et al 2014).…”

Seed traits, seed‐reserve utilization and offspring performance across pre‐industrial to future CO2 concentrations in a Mediterranean community

“…Roots were extracted by gently washing soil from compartments with a rain‐spray nozzle over a 0.5 mm sieve. Data were not shown for Onobrychis crista‐galli because of infection by a pathogen during the course of the experiment (Grünzweig 2011).…”