In the decades since the first cannabinoids were identified by scientists,research has focused almost exclusively on the function and capacity of cannabinoids asmedicines and intoxicants for humans and other vertebrat...In the decades since the first cannabinoids were identified by scientists,research has focused almost exclusively on the function and capacity of cannabinoids asmedicines and intoxicants for humans and other vertebrates.Very little is knownabout the adaptive value of cannabinoid production,though several hypotheses have been proposed including protection from ultraviolet radiation,pathogens,and herbivores.To test the prediction that genotypeswith greater concentrations of cannabinoidswill have reduced herbivory,a segregating F2 population of Cannabis sativa was leveraged to conduct lab-and field-based bioassays investigating the function of cannabinoids in mediating interactions with chewing herbivores.In the field,foliar cannabinoid concentration was inversely correlated with chewing herbivore damage.On detached leaves,Trichoplusia ni larvae consumed less leaf area and grew less when feeding on leaves with greater concentrations of cannabinoids.Scanning electron and light microscopy were used to characterize variation in glandular trichome morphology.Cannabinoid-free genotypes had trichomes that appeared collapsed.To isolate cannabinoids from confounding factors,artificial insect diet was amended with cannabinoids in a range of physiologically relevant concentrations.Larvae grew less and had lower rates of survival as cannabinoid concentration increased.These results support the hypothesis that cannabinoids function in defense against chewing herbivores.展开更多
Sex dimorphism and gene expression were studied in developing catkins in 159 F 2 individuals from the bioenergy crop Salix purpurea,and potential mechanisms and pathways for regulating sex development were explored.Di...Sex dimorphism and gene expression were studied in developing catkins in 159 F 2 individuals from the bioenergy crop Salix purpurea,and potential mechanisms and pathways for regulating sex development were explored.Differential expression,eQTL,bisulfite sequencing,and network analysis were used to characterize sex dimorphism,detect candidate master regulator genes,and identify pathways through which the sex determination region(SDR)may mediate sex dimorphism.Eleven genes are presented as candidates for master regulators of sex,supported by gene expression and network analyses.These include genes putatively involved in hormone signaling,epigenetic modification,and regulation of transcription.eQTL analysis revealed a suite of transcription factors and genes involved in secondary metabolism and floral development that were predicted to be under direct control of the sex determination region.Furthermore,data from bisulfite sequencing and small RNA sequencing revealed strong differences in expression between males and females that would implicate both of these processes in sex dimorphism pathways.These data indicate that the mechanism of sex determination in Salix purpurea is likely different from that observed in the related genus Populus.This further demonstrates the dynamic nature of SDRs in plants,which involves a multitude of mechanisms of sex determination and a high rate of turnover.展开更多
文摘In the decades since the first cannabinoids were identified by scientists,research has focused almost exclusively on the function and capacity of cannabinoids asmedicines and intoxicants for humans and other vertebrates.Very little is knownabout the adaptive value of cannabinoid production,though several hypotheses have been proposed including protection from ultraviolet radiation,pathogens,and herbivores.To test the prediction that genotypeswith greater concentrations of cannabinoidswill have reduced herbivory,a segregating F2 population of Cannabis sativa was leveraged to conduct lab-and field-based bioassays investigating the function of cannabinoids in mediating interactions with chewing herbivores.In the field,foliar cannabinoid concentration was inversely correlated with chewing herbivore damage.On detached leaves,Trichoplusia ni larvae consumed less leaf area and grew less when feeding on leaves with greater concentrations of cannabinoids.Scanning electron and light microscopy were used to characterize variation in glandular trichome morphology.Cannabinoid-free genotypes had trichomes that appeared collapsed.To isolate cannabinoids from confounding factors,artificial insect diet was amended with cannabinoids in a range of physiologically relevant concentrations.Larvae grew less and had lower rates of survival as cannabinoid concentration increased.These results support the hypothesis that cannabinoids function in defense against chewing herbivores.
基金Support for this research was provided by grants(DEB-1542486,DEB-1542599)from the National Science Foundationfrom the USDA National Institute for Food and Agriculture(2015-67009-23957)。
文摘Sex dimorphism and gene expression were studied in developing catkins in 159 F 2 individuals from the bioenergy crop Salix purpurea,and potential mechanisms and pathways for regulating sex development were explored.Differential expression,eQTL,bisulfite sequencing,and network analysis were used to characterize sex dimorphism,detect candidate master regulator genes,and identify pathways through which the sex determination region(SDR)may mediate sex dimorphism.Eleven genes are presented as candidates for master regulators of sex,supported by gene expression and network analyses.These include genes putatively involved in hormone signaling,epigenetic modification,and regulation of transcription.eQTL analysis revealed a suite of transcription factors and genes involved in secondary metabolism and floral development that were predicted to be under direct control of the sex determination region.Furthermore,data from bisulfite sequencing and small RNA sequencing revealed strong differences in expression between males and females that would implicate both of these processes in sex dimorphism pathways.These data indicate that the mechanism of sex determination in Salix purpurea is likely different from that observed in the related genus Populus.This further demonstrates the dynamic nature of SDRs in plants,which involves a multitude of mechanisms of sex determination and a high rate of turnover.
