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We report the identification and biotechnological utility of a plant gene encoding the tocopherol (vitamin E) biosynthetic enzyme 2-methyl-6-phytylbenzoquinol methyltransferase. This gene was identified by map-based cloning of the Arabidopsis mutation vitamin E pathway gene3-1 ( vte3-1 ), which causes increased accumulation of ␦ -tocopherol and decreased ␥ -tocopherol in the seed. Enzyme assays of recombinant protein supported the hypothesis that At-VTE3 encodes a 2-methyl-6-phytylbenzoquinol methyltransferase. Seed-specific expression of At-VTE3 in transgenic soybean reduced seed ␦ -tocopherol from 20 to 2%. These results confirm that At-VTE3 protein catalyzes the methylation of 2-methyl-6-phytylbenzoquinol in planta and show the utility of this gene in altering soybean tocopherol composition. When At-VTE3 was coexpressed with At-VTE4 ( ␥ -tocopherol methyltransferase) in soybean, the seed accumulated to Ͼ 95% ␣ -tocopherol, a dramatic change from the normal 10%, resulting in a greater than eightfold increase of ␣ -tocopherol and an up to fivefold increase in seed vitamin E activity. These findings demonstrate the utility of a gene identified in Arabidopsis to alter the tocopherol composition of commercial seed oils, a result with both nutritional and food quality implications.

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Poly(hydroxyalkanoates) are natural polymers with thermoplastic properties. One polymer of this class with commercial applicability, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) can be produced by bacterial fermentation, but the process is not economically competitive with polymer production from petrochemicals. Poly(hydroxyalkanoate) production in green plants promises much lower costs, but producing copolymer with the appropriate monomer composition is problematic. In this study, we have engineered Arabidopsis and Brassica to produce PHBV in leaves and seeds, respectively, by redirecting the metabolic flow of intermediates from fatty acid and amino acid biosynthesis. We present a pathway for the biosynthesis of PHBV in plant plastids, and also report copolymer production, metabolic intermediate analyses, and pathway dynamics.

Thickness‐insensitive small molecule acceptors (SMAs) are still a great challenge for developing thick‐film organic solar cells (OSCs) towards practical use. Herein, two SMAs, MF1 and MF2, are designed and synthesized by employing a bifunctional end group with fluorine and methyl moieties. Combined with fused‐ring cores with alkyl side chains, both MF1 and MF2 exhibit ordered π–π stacking and high charge carrier mobilities in neat and blend films. The champion devices based on PM7:MF1 and PM7:MF2 deliver high power conversion efficiencies (PCEs) of 12.4% and 13.7%, and high fill factors (FFs) of 78.3% and 74.5%, respectively. With increasing active layer thickness, the FFs of the OSCs decrease relatively slowly, demonstrating the preferrable properties of MF1 and MF2 in terms of their thickness insensitivity, especially for MF1. As a result, the two thick‐film OSCs achieve over 11% PCEs at an active layer thickness over 400 nm (an FF close to 70% for PM7:MF1) and over 10% PCEs when the thickness is increased up to 500 nm. These are the highest PCEs among OSCs with such active layer thicknesses to date. This work reveals a molecular design strategy by reasonably combining fluorine and methyl together to simultaneously enhance charge carrier mobilities and fine‐tune the morphology, which is beneficial to achieve high‐performance thick‐film OSCs.

Irreversible inhibition of transcriptional cyclin-dependent kinases (CDKs) provides a therapeutic strategy for cancers that rely on aberrant transcription; however, lack of understanding of resistance mechanisms to these agents will likely impede their clinical evolution. Here, we demonstrate upregulation of multidrug transporters ABCB1 and ABCG2 as a major mode of resistance to THZ1, a covalent inhibitor of CDKs 7, 12, and 13 in neuroblastoma and lung cancer. To counter this obstacle, we developed a CDK inhibitor, E9, that is not a substrate for ABC transporters, and by selecting for resistance, determined that it exerts its cytotoxic effects through covalent modification of cysteine 1039 of CDK12. These results highlight the importance of considering this common mode of resistance in the development of clinical analogs of THZ1, identify a covalent CDK12 inhibitor that is not susceptible to ABC transporter-mediated drug efflux, and demonstrate that target deconvolution can be accomplished through selection for resistance.

Generally, the electron-withdrawing substitution on the end-capping group of the acceptor−donor−acceptor type small-molecule acceptor (SMA) narrows the optical bandgap, and the electron-donating group lifts the lowest unoccupied molecular orbital (LUMO) energy level of nonfullerene SMA, which increase the short-circuit current density (J SC ) and open circuit voltage (V OC ) of the organic solar cells (OSCs), respectively; however, their synergistic effect on the properties of SMA has remained elusive. Here, we first report a new end-capping group (EG), namely, 5-fluoro-6-methyl-3-dicycanovinylindan-1-one (CFDCI), that concurrently possesses an electron-withdrawing fluorine substitute and an electron-donating methyl group. A prototype SMA (namely, ITCF) based on CFDCI and its two control counterparts were prepared to fully understand the structure− property relationship that the new EG exerts on the resultant SMA. The ITCF demonstrated a moderately crystalline morphology in pristine film and more balanced charge transport properties as well as a reduced amount of bimolecular recombination in blend film in comparison with its counterparts. The ITCF-based devices demonstrated a high power conversion efficiency (PCE) of 13.25% with an outstanding fill factor (FF) of 78.8%, which significantly outperformed their counterparts. Our study provides an important strategy to judiciously tune the properties of the SMAs for improving the performance of the OSCs.

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