Project description:We analysed the transcriptomic response of 3 rhizobial symbionts of Mimosa pudica (Rhizobium mesoamericanum STM3625, Cupriavidus taiwanensis LMG19424 and Burkholderia phymatum STM815) when cultivated in a minimum culture medium (control condition) versus induced by root exudates of their host plant Mimosa pudica. We used RNAseq using illumina technology.
Project description:Plants make foraging decisions that are dependent on ecological conditions, such as resource availability and distribution. Despite the field of plant behavioral ecology gaining momentum, ecologists still know little about what factors impact plant behavior, especially light-foraging behavior. We made use of the behavioral reaction norm approach to investigate light foraging in a plant species that exhibits rapid movement: Mimosa pudica. We explored how herbivore avoidance behavior in M. pudica (which closes its leaflets temporarily when disturbed) is affected by an individual's energy state and the quality of the current environment and also repeatedly tested the behavior of individuals from two seed sources to determine whether individuals exhibit a "personality" (i.e., behavioral syndrome). We found that when individuals are in a low-energy state, they adopt a riskier light-foraging strategy, opening leaflets faster, and not closing leaflets as often in response to a disturbance. However, when plants are in a high-energy state, they exhibit a plastic light-foraging strategy dependent on environment quality. Although we found no evidence that individuals exhibit behavioral syndromes, we found that individuals from different seed sources consistently behave differently from each other. Our results suggest that plants are capable of making state-dependent decisions and that plant decision making is complex, depending on the interplay between internal and external factors.
Project description:Slow wave potentials (SWPs) are damage-induced electrical signals which, based on experiments in which organs are burned, have been linked to rapid increases in leaf or stem thickness. The possibility that pressure surges in injured xylem underlie these events has been evoked frequently. We sought evidence for insect feeding-induced positive pressure changes in the petioles of Arabidopsis thaliana Instead, we found that petiole surfaces of leaves distal to insect-feeding sites subsided. We also found that insect damage induced longer-duration downward leaf movements in undamaged leaves. The transient petiole deformations were contemporary with and dependent on the SWP. We then investigated if mutants that affect the xylem, which has been implicated in SWP transmission, might modify SWP architecture. irregular xylem mutants strongly affected SWP velocity and kinetics and, in parallel, restructured insect damage-induced petiole deformations. Together, with force change measurements on the primary vein, the results suggest that extravascular water fluxes accompany the SWP. Moreover, petiole deformations in Arabidopsis mimic parts of the spectacular distal leaf collapse phase seen in wounded Mimosa pudica We genetically link electrical signals to organ movement and deformation and suggest an evolutionary origin of the large leaf movements seen in wounded Mimosa.