@article{zhu_yuzuak_sun_xie_2023, title={Identification and biosynthesis of plant papanridins, a group of novel oligomeric flavonoids}, volume={16}, ISSN={["1752-9867"]}, DOI={10.1016/j.molp.2023.09.015}, abstractNote={The discovery of novel flavonoids and elucidation of their biosynthesis are fundamental to understanding their roles in plants and their benefits for human and animal health. Here, we report a new pathway for polymerization of a group of novel oligomeric flavonoids in plants. We engineered red cells for discovering genes of interest involved in the flavonoid pathway and identified a gene encoding a novel flavanol polymerase (FP) localized in the central vacuole. FP catalyzes the polymerization of flavanols, such as epicatechin and catechin, to produce yellowish dimers or oligomers. Structural elucidation shows that these compounds feature a novel oligomeric flaven–flavan (FF) skeleton linked by interflavan–flaven and interflaven bonds, distinguishing them from proanthocyanidins and dehydrodicatechins. Detailed chemical and physical characterizations further confirmed the novel FFs as flavonoids. Mechanistic investigations demonstrated that FP polymerizes flavan-3-ols and flav-2-en-3-ol carbocation, forming dimeric or oligomeric flaven-4→8-flavans, which we term “papanridins.” Data from transgenic experiments, mutant analysis, metabolic profiling, and phylogenetic analyses show that the biosynthesis of papanridins is prevalent in cacao, grape, blueberry, corn, rice, Arabidopsis, and other species in the plant kingdom. In summary, our study discoveries a group of novel oligomeric flavonoids, namely papanridins, and reveals that a novel FP-mediated polymerization mechanism for the biosynthesis of papanridins in plants.}, number={11}, journal={MOLECULAR PLANT}, author={Zhu, Yue and Yuzuak, Seyit and Sun, Xiaoyan and Xie, De-Yu}, year={2023}, month={Nov}, pages={1773–1793} }
 @article{judd_dong_sun_zhu_li_xie_2023, title={Metabolic engineering of the anthocyanin biosynthetic pathway in Artemisia annua and relation to the expression of the artemisinin biosynthetic pathway}, volume={257}, ISSN={["1432-2048"]}, url={https://doi.org/10.1007/s00425-023-04091-6}, DOI={10.1007/s00425-023-04091-6}, abstractNote={Four types of cells were engineered from Artemisia annua to produce approximately 17 anthocyanins, four of which were elucidated structurally. All of them expressed the artemisinin pathway. Artemisia annua is the only medicinal crop to produce artemisinin for the treatment of malignant malaria. Unfortunately, hundreds of thousands of people still lose their life every year due to the lack of sufficient artemisinin. Artemisinin is considered to result from the spontaneous autoxidation of dihydroartemisinic acid in the presence of reactive oxygen species (ROS) in an oxidative condition of glandular trichomes (GTs); however, whether increasing antioxidative compounds can inhibit artemisinin biosynthesis in plant cells is unknown. Anthocyanins are potent antioxidants that can remove ROS in plant cells. To date, no anthocyanins have been structurally elucidated from A. annua. In this study, we had two goals: (1) to engineer anthocyanins in A. annua cells and (2) to understand the artemisinin biosynthesis in anthocyanin-producing cells. Arabidopsis Production of Anthocyanin Pigment 1 was used to engineer four types of transgenic anthocyanin-producing A. annua (TAPA1-4) cells. Three wild-type cell types were developed as controls. TAPA1 cells produced the highest contents of total anthocyanins. LC-MS analysis detected 17 anthocyanin or anthocyanidin compounds. Crystallization, LC/MS/MS, and NMR analyses identified cyanidin, pelargonidin, one cyanin, and one pelargonin. An integrative analysis characterized that four types of TAPA cells expressed the artemisinin pathway and TAPA1 cells produced the highest artemisinin and artemisinic acid. The contents of arteannuin B were similar in seven cell types. These data showed that the engineering of anthocyanins does not eliminate the biosynthesis of artemisinin in cells. These data allow us to propose a new hypothesis that enzymes catalyze the formation of artemisinin from dihydroartemisinic acid in non-GT cells. These findings show a new platform to increase artemisinin production via non-GT cells of A. annua.}, number={3}, journal={PLANTA}, author={Judd, Rika and Dong, Yilun and Sun, Xiaoyan and Zhu, Yue and Li, Mingzhuo and Xie, De-Yu}, year={2023}, month={Mar} }
 @article{sulis_jiang_yang_marques_matthews_miller_lan_cofre-vega_liu_sun_et al._2023, title={Multiplex CRISPR editing of wood for sustainable fiber production}, volume={381}, ISSN={["1095-9203"]}, url={http://europepmc.org/abstract/med/37440632}, DOI={10.1126/science.add4514}, abstractNote={The domestication of forest trees for a more sustainable fiber bioeconomy has long been hindered by the complexity and plasticity of lignin, a biopolymer in wood that is recalcitrant to chemical and enzymatic degradation. Here, we show that multiplex CRISPR editing enables precise woody feedstock design for combinatorial improvement of lignin composition and wood properties. By assessing every possible combination of 69,123 multigenic editing strategies for 21 lignin biosynthesis genes, we deduced seven different genome editing strategies targeting the concurrent alteration of up to six genes and produced 174 edited poplar variants. CRISPR editing increased the wood carbohydrate-to-lignin ratio up to 228% that of wild type, leading to more-efficient fiber pulping. The edited wood alleviates a major fiber-production bottleneck regardless of changes in tree growth rate and could bring unprecedented operational efficiencies, bioeconomic opportunities, and environmental benefits.}, number={6654}, journal={SCIENCE}, author={Sulis, Daniel B. and Jiang, Xiao and Yang, Chenmin and Marques, Barbara M. and Matthews, Megan L. and Miller, Zachary and Lan, Kai and Cofre-Vega, Carlos and Liu, Baoguang and Sun, Runkun and et al.}, year={2023}, month={Jul}, pages={216-+} }