Influence of genotypes and environmental factors on leaf triterpenoid content and growth of Cyclocarya paliurus

Cyclocarya paliurus, an economically valuable tree species, has traditionally been used as a nutraceutical food or medicine in China. However, limited information is available on its genotype selection and cultivation under a wide range of environmental conditions for growth and targeted health-promoting substances. We studied the effects of genotype and environment, and their interaction on leaf triterpenoid content and tree growth for 12 genotypes of C. paliurus grown at four sites. We quantified the correlation between leaf triterpenoid accumulation and tree growth. The contents of cyclocaric acid B, cyclocarioside I, and arjunolic acid ranged from 0.06 to 3.89, 0 to 3.71, and 0.65 to 8.86 mg g^-1, respectively. Three individual triterpenoids were primarily influenced by genotype (variation ranged from 53.7 to 68.0%), while environment accounted for most of the variation in total triterpenoid content and tree growth (71.3–89.5%). Most tested environmental parameters were significantly correlated to total triterpenoid content, but not to the contents of the individual triterpenoids measured. Growth in tree height and diameter at breast height were significantly negatively correlated with total triterpenoid content but were non-significantly correlated with individual triterpenoid contents. We conclude that genotypic selection, manipulation of environmental conditions, and implementation of appropriate silvicultural operations would be important strategies for increasing the accumulation of health-promoting phytochemicals.

Nickel-catalyzed arylcyanation of alkenes via cyano group translocation:access to 1,n-dinitriles or 4-amino nitriles

Herein,a nickel-catalyzed arylcyanation of unactivated alkenes via cyano group translocation with aryl boronic acids has been developed.These transformations provided a robust approach to constructing structurally diverse 1,n-dinitriles or 4-amino nitriles from easily prepared and commercially available starting materials.The cyano group translocation was achieved,involving the addition into the intramolecular C–N triple bond followed by the retro-Thorpe reaction.Mechanistic studies revealed that high temperature and CsHCO_(3) as the base were crucial for the cyano group translocation.

Whole-genome Duplication Reshaped Adaptive Evolution in A Relict Plant Species,Cyclocarya paliurus

Cyclocarya paliurus is a relict plant species that survived the last glacial period and shows a population expansion recently.Its leaves have been traditionally used to treat obesity and diabetes with the well-known active ingredient cyclocaric acid B.Here,we presented three C.paliurus genomes from two diploids with different flower morphs and one haplotype-resolved tetraploid assembly.Comparative genomic analysis revealed two rounds of recent whole-genome duplication events and identified 691 genes with dosage effects that likely contribute to adaptive evolution through enhanced photosynthesis and increased accumulation of triterpenoids.Resequencing analysis of 45 C.paliurus individuals uncovered two bottlenecks,consistent with the known events of environmental changes,and many selectively swept genes involved in critical biological functions,including plant defense and secondary metabolite biosynthesis.We also proposed the biosynthesis pathway of cyclocaric acid B based on multi-omics data and identified key genes,in particular gibberellinrelated genes,associated with the heterodichogamy in C.paliurus species.Our study sheds light on evolutionary history of C.paliurus and provides genomic resources to study the medicinal herbs.