Thursday, February 26, 2015
Pot size alters plant responses to water deficit: a multiscale analysis in oilseed rape (Brassica napus L.)
Post-Doctorante LEPSE – équipe SPIC
Following the recent development of high-throughput phenotyping platforms for plant research, the number of pots grown together in a same experiment has raised, sometimes at the expense of the soil volume available for each plant. However, soil volume affects plant growth and the components of its carbon budget, which may interact with other abiotic stresses. Here, we investigated the interactive effects of pot size and soil water deficit on multiple vegetative growth traits from the cellular to the whole-plant scale. Several spring oilseed rape (Brassica napus L.) genotypes were analyzed. Preliminary experiments were carried out to choose soil types and humidities, and to focus on a subset of contrasted genotypes. The effects of pot size on drought responses and allometric relationships were strongly dependent on the considered growth trait and genotype, revealing strong, multilevel interactions between the pot size and the watering regime. Notably, the root:shoot ratio was increased by water deficit in large pots, as usually reported in the literature, but remained unchanged in small pots. At the cellular scale, soil water deficit increased stomatal and epidermal cell density in large pots, but not in small pots. Flow cytometry analyses showed that the endoreduplication process was probably involved in the variation of these cellular responses. These results illustrate that plant responses to drought stress can be mitigated by pot capacity.
Contact : Christine Granier