[Exploration of transcriptome SSR markers and its application in genetic diversity assessment of Asarum sieboldii].

To explore the genetic diversity of Asarum sieboldii this study developed SSR markers based on transcriptome sequencing results and five populations of A.sieboldii from different regions were used as samples for genetic diversity assessment using software such as GenALEx 6.5, NTSYS 2.1, and Structure 2.3.4. The results showed that 16 SSR markers with high polymorphism and good repeatability were selected from the A.sieboldii transcriptome. Primers designed based on the flanking sequences of these markers successfully amplified 56 polymorphic fragments from 150 individual samples of the five A.sieboldii populations. On average, each primer amplified 3.5 polymorphic fragments, ranging from 2 to 8. The mean values of expected heterozygosity(H_e), Shannon's diversity index(I), Nei's gene diversity index(H), and the polymorphic information content(PIC) were 0.172, 0.281, 0.429, and 0.382, respectively. The mean population differentiation coefficient(F_(ST)) was 0.588, consistent with the analysis of molecular variance(AMOVA) results, which indicated greater genetic variation among A.sieboldii populations(69%) than that within populations(31%). The percentage of polymorphic loci(PPL) ranged from highest to lowest as SNJ>LN>SY>SZ>TB. Principal coordinate analysis(PCoA) and UPGMA clustering analysis further revealed genetic clustering of A.sieboldii individuals based on their geographical distribution, consistent with the results of the structure clustering analysis. In summary, the SSR markers developed from the transcriptome effectively assessed the genetic differentiation and population structure of natural A.sieboldii populations, revealing a relatively low genetic diversity in A.sieboldii, with genetic variation primarily observed at the population level and a correlation between population differentiation and geographic distance.

Caffeoyl-coenzyme A O-methyltransferase mediates regulation of carbon flux fluctuations during phenylpropenes and lignin biosynthesis in the vegetative organ roots of Asarum sieboldii Miq.

Asarum sieboldii Miq. possesses remarkable medicinal value due to its essential oil enriched with phenylpropenes (e.g., methyleugenol and safrole). Although the biosynthesis of phenylpropenes shares a common pathway with lignin, the regulation mechanisms in carbon flux allocation between them are unclear. This study is the first to genetically verify the carbon flux regulation mechanism in A. sieboldii roots. We regulated the expression of Caffeoyl-coenzyme A O-methyltransferase (CCoAOMT), an essential enzyme in the common pathway, to investigate carbon flux allocation in vegetative organs. Here, the lignin and phenylpropene content fluctuation was analyzed by wet chemistry and GC-MS methods. A bona fide CCoAOMT gene from A. sieboldii was firstly cloned and verified. Preliminary heterologous expression validation in transgenic Arabidopsis thaliana showed that RNAi-induced CCoAOMT down-regulation significantly decreased lignin content by 24% and increased the S/G ratio by 30%; however, AsCCoAOMT over-expression in A. thaliana resulted in a 40% increase in lignin content and a 20% decrease in the S/G ratio when compared to the wild type. Similar trends were noted in homologous transformation in A. sieboldii, although the variations were not conspicuous. Nevertheless, the transgenic A. sieboldii plants displayed substantial differences in the level of phenylpropene compounds methyleugenol and safrole leading to a 168% increase in the methyleugenol/safrole ratio in the over-expression line and a 73% reduction in RNAi-suppression line. These findings suggest that the biosynthesis of phenylpropene constituents methyleugenol and safrole seems to be prioritized over lignin. Furthermore, this study indicated that suppression of AsCCoAOMT resulted in marked root susceptibility to pathogenic fungal disease, implying a significant additional role of CCoAOMT in protecting plant vegetative parts from diseases. Overall, the present study provides important references and suggests that future research should be aimed at elucidating the detailed mechanisms of the carbon flux allocation between phenylpropenes and lignin biosynthesis, as well as the disease resistance competency.

Flexible Sensor for Invisible Respiratory Monitoring via Construction of a 2D Stacked Micronetwork.

With the advent of 5G and the Internet of Things era, sensitive and stable sensors have begun to develop rapidly, which are important substantial fundaments of smart medical care. In this study, based on the positive temperature coefficient (PTC) in conductive polymer composites (CPC), a novel polyolefin elastomer (POE)/carbon fiber (CF) composite was prepared. By regulating the rheological behavior of the polymer matrix, we realized its controllable thermal expansion in the temperature field and finally realized the reversible construction-destruction of the conductive CF network. Under optimal molecular weight conditions, the POE/CF PTC sensor showed a high sensitivity of 0.11 °C-1 and stability. It was also demonstrated that the heat transfer efficiency of the composite material played an essential role in the sensitivity of the as-prepared PTC sensor. Most impressively, we have assembled an invisible respiratory monitoring device based on the POE/CF composite to achieve real-time monitoring of human breathing, which displayed wide potential prospects in thermal monitoring and provided good prospects for micron-scale functional composites.