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SUMMARY: Flavan‐3‐ols are prominent phenolic compounds found abundantly in the young leaves of tea plants. The enzymes involved in flavan‐3‐ol biosynthesis in tea plants have been extensively investigated. However, the localization and associations of these numerous functional enzymes within cells have been largely neglected. In this study, we aimed to investigate the synthesis of flavan‐3‐ols in tea plants, particularly focusing on epigallocatechin gallate. Our analysis involving the DESI‐MSI method to reveal a distinct distribution pattern of B‐ring trihydroxylated flavonoids, primarily concentrated in the outer layer of buds. Subcellular localization showed that CsC4H, CsF3′H, and CsF3′5′H localizes endoplasmic reticulum. Protein–protein interaction studies demonstrated direct associations between CsC4H, CsF3′H, and cytoplasmic enzymes (CHS, CHI, F3H, DFR, FLS, and ANR), highlighting their interactions within the biosynthetic pathway. Notably, CsF3′5′H, the enzyme for B‐ring trihydroxylation, did not directly interact with other enzymes. We identified cytochrome b5 isoform C serving as an essential redox partner, ensuring the proper functioning of CsF3′5′H. Our findings suggest the existence of distinct modules governing the synthesis of different B‐ring hydroxylation compounds. This study provides valuable insights into the mechanisms underlying flavonoid diversity and efficient synthesis and enhances our understanding of the substantial accumulation of B‐ring trihydroxylated flavan‐3‐ols in tea plants. Significance Statement: Our work reveals the mechanism of flavonoid diversity and efficient synthesis in tea plants from the perspective of metabolon. Different metabolons modules provide a new perspective on the scientific problem of why tea plants accumulate high levels of EGCG. The discovery of obligate electron shuttle proteins provides new directions for improving metabolic engineering. [ABSTRACT FROM AUTHOR]

Objective To investigate the clinical features and prognosis of HIV-negative plasmablastic lymphoma (PBL) patients. Methods We collected HIV-negative PBL cases reported in our hospital and other literatures from online databases from January 1, 1997 to March 30, 2020. The data of clinical features, molecular pathology, treatment and prognosis were summarized and analyzed. Results We included 60 PBL patients, average age was 53.06±14.36 years, and most of them had relatively high Ann Arbor stage and Ki-67 expression. The average OS was 13.48±13.21 m. Kaplan-Meier curve revealed Ann Arbor stage, IPI index (3-5), B symptoms and CR in initial treatment were significantly related with patients' survival. Cox regression analysis indicated that the Ann Arbor stage and IPI index were the independent prognostic factors for patients' survival. Conclusion HIV-negative PBL mostly occurs in the middle-age and elderly patients, with advanced diagnosis stage and rapid tumor proliferation. Combination chemotherapy is the main treatment, while the therapeutic response and OS might be heterogeneous, the prognosis of most patients would be poor. The stage and IPI index are significantly related to the prognosis.

Tea is an important cash crop that is often consumed by chewing pests, resulting in reduced yields and economic losses. It is important to establish a method to quickly identify the degree of damage to tea plants caused by leaf‐eating insects and screen green control compounds. This study was performed through the combination of deep learning and targeted metabolomics, in vitro feeding experiment, enzymic analysis and transient genetic transformation. A small target damage detection model based on YOLOv5 with Transformer Prediction Head (TPH‐YOLOv5) algorithm for the tea canopy level was established. Orthogonal partial least squares (OPLS) was used to analyze the correlation between the degree of damage and the phenolic metabolites. A potential defensive compound, (‐)‐epicatechin‐3‐O‐caffeoate (EC‐CA), was screened. In vitro feeding experiments showed that compared with EC and epicatechin gallate, Ectropis grisescens exhibited more significant antifeeding against EC‐CA. In vitro enzymatic experiments showed that the hydroxycinnamoyl transferase (CsHCTs) recombinant protein has substrate promiscuity and can catalyze the synthesis of EC‐CA. Transient overexpression of CsHCTs in tea leaves effectively reduced the degree of damage to tea leaves. This study provides important reference values and application prospects for the effective monitoring of pests in tea gardens and screening of green chemical control substances. Summary statement: Based on deep learning and targeted metabolomics, a model was established and (‐)‐epicatechin‐3‐O‐caffeoate (EC‐CA) was screened to have the function of defense against chewing pests, and hydroxycinnamoyl transferase (HCT) was identified as a substrate promiscuity that could efficiently catalyze the synthesis of EC‐CA. [ABSTRACT FROM AUTHOR]