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.

Steganalysis of Low Embedding Rate CNV-QIM in Speech

To address the difficulty of detecting low embedding rate and high-concealment CNV-QIM(complementary neighbor vertices-quantization index modulation)steganography in low bit-rate speech codec,the code-word correlation model based on a BiLSTM(bi-directional long short-term memory)neural network is built to obtain the correlation features of the LPC codewords in speech codec in this paper.Then,softmax is used to classify and effectively detect low embedding rate CNV-QIM steganography in VoIP streams.The experimental results show that for speech steganography of short samples with low embedding rate,the BiLSTM method in this paper has a superior detection accuracy than state-of-the-art methods of the RNN-SM(recurrent neural network-steganalysis model)and SS-QCCN(simplest strong quantization codeword correlation network).At an embedding rate of 20%and a duration of 3 s,the detection accuracy of BiLSTM method reaches 75.7%,which is higher than that of RNNSM by 11.7%.Furthermore,the average testing time of samples(100%embedding)is 0.3 s,which shows that the method can realize real-time steganography detection of VoIP streams.

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.