Summary: Here we report the draft genome sequence of perennial ryegrass (Lolium perenne), an economically important forage and turf grass species that is widely cultivated in temperate regions worldwide. It is classified along with wheat, barley, oats and Brachypodium distachyon in the Pooideae sub‐family of the grass family (Poaceae). Transcriptome data was used to identify 28 455 gene models, and we utilized macro‐co‐linearity between perennial ryegrass and barley, and synteny within the grass family, to establish a synteny‐based linear gene order. The gametophytic self‐incompatibility mechanism enables the pistil of a plant to reject self‐pollen and therefore promote out‐crossing. We have used the sequence assembly to characterize transcriptional changes in the stigma during pollination with both compatible and incompatible pollen. Characterization of the pollen transcriptome identified homologs to pollen allergens from a range of species, many of which were expressed to very high levels in mature pollen grains, and are potentially involved in the self‐incompatibility mechanism. The genome sequence provides a valuable resource for future breeding efforts based on genomic prediction, and will accelerate the development of new varieties for more productive grasslands.

Aims: To investigate the role of endogenous hydrogen sulfide (H ₂ S) in the control of aging and healthspan of Caenorhabditis elegans. Results: We show that the model organism, C. elegans , synthesizes H ₂ S. Three H ₂ S-synthesizing enzymes are present in C. elegans , namely cystathionine γ lyase (CSE), cystathionine β synthetase, and 3-mercaptopyruvate transferase (MPST or 3-MST). Genetic deficiency of mpst-1 (3-MST orthologue 1), but not cth-2 (CSE orthologue), reduced the lifespan of C. elegans . This effect was reversed by a pharmacological H ₂ S donor (GYY4137). GYY4137 also reduced detrimental age-dependent changes in a range of physiological indices, including pharyngeal contraction and defecation. Treatment of C. elegans with GYY4137 increased the expression of several age-related, stress response, and antioxidant genes, whereas MitoSOX Red fluorescence, indicative of reactive oxygen species generation, was increased in mpst-1 knockouts and decreased by GYY4137 treatment. GYY4137 additionally increased the lifespan in short-lived mev-1 mutants with elevated oxidative stress and protected wild-type C. elegans against paraquat poisoning. The lifespan-prolonging and health-promoting effects of H ₂ S in C. elegans are likely due to the antioxidant action of this highly cell-permeable gas. Innovation: The possibility that novel pharmacological agents based on the principle of H ₂ S donation may be able to retard the onset of age-related disease by slowing the aging process warrants further study. Conclusion: Our results show that H ₂ S is an endogenous regulator of oxidative damage, metabolism, and aging in C. elegans and provide new insight into the mechanisms, which control aging in this model organism. Antioxid. Redox Signal. 20, 2621–2630.

Background: Physiologically based modelling using DEBtox (dynamic energy budget in toxicology) and transcriptional profiling were used inCaenorhabditis elegansto identify how physiological modes of action, as indicated by effects on system level resource allocation were associated with changes in gene expression following exposure to three toxic chemicals: cadmium, fluoranthene (FA) and atrazine (AZ).Results: For Cd, the physiological mode of action as indicated by DEBtox model fitting was an effect on energy assimilation from food, suggesting that the transcriptional response to exposure should be dominated by changes in the expression of transcripts associated with energy metabolism and the mitochondria. While evidence for effect on genes associated with energy production were seen, an ontological analysis also indicated an effect of Cd exposure on DNA integrity and transcriptional activity. DEBtox modelling showed an effect of FA on costs for growth and reproduction (i.e. for production of new and differentiated biomass). The microarray analysis supported this effect, showing an effect of FA on protein integrity and turnover that would be expected to have consequences for rates of somatic growth. For AZ, the physiological mode of action predicted by DEBtox was increased cost for maintenance. The transcriptional analysis demonstrated that this increase resulted from effects on DNA integrity as indicated by changes in the expression of genes chromosomal repair.Conclusions: Our results have established that outputs from process based models and transcriptomics analyses can help to link mechanisms of action of toxic chemicals with resulting demographic effects. Such complimentary analyses can assist in the categorisation of chemicals for risk assessment purposes.