Plant secondary metabolites (SMs) acting as defensive chemicals in reproductive organs such as fruit tissues play roles in both mutualistic and antagonistic interactions between plants and seed dispersers/predators. The directed-deterrence hypothesis states that SMs in ripe fruits deter seed predators but have little or no effect on seed dispersers. Indeed, studies have demonstrated that birds are able to cope with fruit SMs whereas rodents are deterred by them. However, this mechanism was only demonstrated at the class level, i.e., between birds and mammals, based on differences in the vanilloid receptors. Here we present experimental and behavioral data demonstrating the use of the broad-range, class-independent "mustard oil bomb" mechanism in Ochradenus baccatus fruits to force a behavioral change at an ecological timescale, converting rodents from seed predators to seed dispersers. This is achieved by a unique compartmentalization of the mustard oil bomb, causing activation of the system only upon seed and pulp coconsumption, encouraging seed dispersal via seed spitting by rodents. Our findings demonstrate the power of SMs to shift the animal-plant relationship from predation to mutualism and provide support for the directed-deterrence hypothesis at the intraspecific level, in addition to the interspecific level.

Background:The phycobilisome is assembled from many subunits, but the entire structure has not been determined. Results: Coupled cross-linking/MS revealed neighboring residues within the interfaces between subunits. Conclusion: The rods completely cover the core cylinders and are not in a staggered assembly form. Significance: Energy transfer from rods to cores overcomes a jump of over 30 Å without loss of efficiency.

The COP9 signalosome (CSN) is a conserved eukaryotic complex, essential for vitality in all multicellular organisms and critical for the turnover of key cellular proteins through catalytic and non‐catalytic activities. Saccharomyces cerevisiae is a powerful model organism for studying fundamental aspects of the CSN complex, since it includes a conserved enzymatic core but lacks non‐catalytic activities, probably explaining its non‐essentiality for life. A previous transcriptomic analysis of an S. cerevisiae strain deleted in the CSN5/RRI1 gene, encoding to the CSN catalytic subunit, revealed a downregulation of genes involved in lipid metabolism. We now show that the S. cerevisiae CSN holocomplex is essential for cellular lipid homeostasis. Defects in CSN assembly or activity lead to decreased quantities of ergosterol and unsaturated fatty acids (UFA); vacuole defects; diminished lipid droplets (LDs) size; and to accumulation of endoplasmic reticulum (ER) stress. The molecular mechanism behind these findings depends on CSN involvement in upregulating mRNA expression of SPT23. Spt23 is a novel activator of lipid desaturation and ergosterol biosynthesis. Our data reveal for the first time a functional link between the CSN holocomplex and Spt23. Moreover, CSN‐dependent upregulation of SPT23 transcription is necessary for the fine‐tuning of lipid homeostasis and for cellular health.