Electronic eye and electronic tongue data fusion combined with a GETNet model for the traceability and detection of Astragalus.

BACKGROUND: Astragalus is a widely used traditional Chinese medicine material that is easily confused due to its quality, price and other factors derived from different origins. This article describes a novel method for the rapid tracing and detection of Astragalus via the joint application of an electronic tongue (ET) and an electronic eye (EE) combined with a lightweight convoluted neural network (CNN)-transformer model. First, ET and EE systems were employed to measure the taste fingerprints and appearance images, respectively, of different Astragalus samples. Three spectral transform methods - the Markov transition field, short-time Fourier transform and recurrence plot - were utilized to convert the ET signals into 2D spectrograms. Then, the obtained ET spectrograms were fused with the EE image to obtain multimodal information. A lightweight hybrid model, termed GETNet, was designed to achieve pattern recognition for the Astragalus fusion information. The proposed model employed an improved transformer module and an improved Ghost bottleneck as its backbone network, complementarily utilizing the benefits of CNN and transformer architectures for local and global feature representation. Furthermore, the Ghost bottleneck was further optimized using a channel attention technique, which boosted the model's feature extraction effectiveness. RESULTS: The experiments indicate that the proposed data fusion strategy based on ET and EE devices has better recognition accuracy than that attained with independent sensing devices. CONCLUSION: The proposed method achieved high precision (99.1%) and recall (99.1%) values, providing a novel approach for rapidly identifying the origin of Astragalus, and it holds great promise for applications involving other types of Chinese herbal medicines. © 2024 Society of Chemical Industry.

Role of Endophytic Bacteria in the Remobilization of Leaf Nitrogen Mediated by CsEGGT in Tea Plants (Camellia sinensis L.).

As an important economic plant, tea (Camellia sinensis) has a good economic value and significant health effects. Theanine is an important nitrogen reservoir, and its synthesis and degradation are considered important for nitrogen storage and remobilization in tea plants. Our previous research indicated that the endophyte CsE7 participates in the synthesis of theanine in tea plants. Here, the tracking test confirmed that CsE7 tended to be exposed to mild light and preferentially colonized mature tea leaves. CsE7 also participated in glutamine, theanine, and glutamic acid circulatory metabolism (Gln-Thea-Glu) and contributed to nitrogen remobilization, mediated by the γ-glutamyl-transpeptidase (CsEGGT) with hydrolase preference. The reisolation and inoculation of endophytes further verified their role in accelerating the remobilization of nitrogen, especially in the reuse of theanine and glutamine. This is the first report about the photoregulated endophytic colonization and the positive effect of endophytes on tea plants mediated and characterized by promoting leaf nitrogen remobilization.

γ-Glutamyl-transpeptidase CsGGT2 functions as light-activated theanine hydrolase in tea plant (Camellia sinensis L.).

Theanine is an important secondary metabolite endowing tea with umami taste and health effects. It is essential to explore the metabolic pathway and regulatory mechanism of theanine to improve tea quality. Here, we demonstrated that the expression patterns of CsGGT2 (γ-glutamyl-transpeptidase), participated in theanine synthesis in vitro in our previous research, are significantly different in the aboveground and underground tissues of tea plants and regulated by light. Light up-regulated the expression of CsHY5, directly binding to the promoter of CsGGT2 and acting as an activator of CsGGT2, with a negative correlation with theanine accumulation. The enzyme activity assays and transient expression in Nicotiana benthamiana showed that CsGGT2, acting as bifunctional protein, synthesize and degrade theanine in vitro and in planta. The results of enzyme kinetics, Surface plasmon resonance (SPR) assays and targeted gene-silencing assays showed that CsGGT2 had a higher substrate affinity of theanine than that of ethylamine, and performed a higher theanine degradation catalytic efficiency. Therefore, light mediates the degradation of theanine in different tissues by regulating the expression of the theanine hydrolase CsGGT2 in tea plants, and these results provide new insights into the degradation of theanine mediated by light in tea plants.