Transgenerational effects of elevated CO 2 : Downregulation of
photosynthetic efficiency and stomatal sensitivity to drought
Abstract
Increasing atmospheric CO 2 and drought are major
symptoms of anthropogenic climate change with profound effects on plant
growth. Transgenerational memory (i.e. influence of the parental
environment on offspring phenotype and performance) has been suggested
as a relevant mechanism for plants to build-up adaptative capacity for
rapid environmental changes. However, this mechanism of pre-adaptation
remains poorly investigated so far. We investigated intra- and
transgenerational effects of elevated CO 2 on drought
response of wheat. We used seeds from a FACE (Free Air Carbon Dioxide
Enrichment) experiment with ambient and elevated CO 2 to
grow plants in climate chambers in which we varied CO 2,
atmospheric water demand and soil moisture. We quantified photosynthetic
efficiency, stomatal sensitivity and biomass production. We observed
intragenerational upregulation of photosynthetic efficiency but
transgenerational downregulation of photosynthetic efficiency, stomatal
sensitivity and water use efficiency as response to maternally elevated
CO 2. Plant biomass was affected by drought and
experimental CO 2 but not by maternal CO
2. Our study showcases the importance of
transgenerational memory effects when studying climate change response
of plants and could have major implications for our understanding of
global dynamics of carbon sequestration. It highlights the pressing need
for multi-generational experiments accounting for transgenerational
memory effects of elevated CO 2.