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1. The maize PLASTID TERMINAL OXIDASE ( PTOX ) locus controls the carotenoid content of kernels

   https://doi.org/10.1111/tpj.16618  

   Nie, Yongxin; Wang, Hui; Zhang, Guan; Ding, Haiping; Han, Beibei; Liu, Lei; Shi, Jian; Du, Jiyuan; Li, Xiaohu; Li, Xinzheng; et al (April 2024, The Plant Journal)

   SUMMARY Carotenoids perform a broad range of important functions in humans; therefore, carotenoid biofortification of maize (Zea maysL.), one of the most highly produced cereal crops worldwide, would have a global impact on human health.PLASTID TERMINAL OXIDASE(PTOX) genes play an important role in carotenoid metabolism; however, the possible function ofPTOXin carotenoid biosynthesis in maize has not yet been explored. In this study, we characterized the maizePTOXlocus by forward‐ and reverse‐genetic analyses. While most higher plant species possess a single copy of thePTOXgene, maize carries two tandemly duplicated copies. Characterization of mutants revealed that disruption of either copy resulted in a carotenoid‐deficient phenotype. We identified mutations in thePTOXgenes as being causal of the classic maize mutant,albescent1. Remarkably, overexpression ofZmPTOX1significantly improved the content of carotenoids, especially β‐carotene (provitamin A), which was increased by ~threefold, in maize kernels. Overall, our study shows that maizePTOXlocus plays an important role in carotenoid biosynthesis in maize kernels and suggests that fine‐tuning the expression of this gene could improve the nutritional value of cereal grains. 

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2. Anatomy and relationships of the early diverging Crocodylomorphs Junggarsuchus sloani and Dibothrosuchus elaphros

   https://doi.org/10.1002/ar.24949  

   Ruebenstahl, Alexander A.; Klein, Michael D.; Yi, Hongyu; Xu, Xing; Clark, James M. (October 2022, The Anatomical Record)
3. Structural stability and the low‐lying singlet and triplet states of BN ‐ n ‐acenes, n  = 1–7

   https://doi.org/10.1002/jcc.27038  

   Milanez, Bruno D.; dos Santos, Gustavo M.; Pinheiro, Jr, Max; Ueno, Leonardo T.; Ferrão, Luiz F. A.; Aquino, Adelia J. A.; Lischka, Hans; Machado, Francisco B. C. (November 2022, Journal of Computational Chemistry)

   Abstract The chemical stability and the low‐lying singlet and triplet excited states of BN‐n‐acenes (n = 1–7) were studied using single reference and multireference methodologies. From the calculations, descriptors such as the singlet‐triplet splitting, the natural orbital (NO) occupations and aromaticity indexes are used to provide structural and energetic analysis. The boron and nitrogen atoms form an isoelectronic pair of two carbon atoms, which was used for the complete substitution of these units in the acene series. The structural analysis confirms the effects originated from the insertion of a uniform pattern of electronegativity difference within the molecular systems. The covalent bonds tend to be strongly polarized which does not happen in the case of a carbon‐only framework. This effect leads to a charge transfer between neighbor atoms resulting in a more strengthened structure, keeping the aromaticity roughly constant along the chain. The singlet‐triplet splitting also agrees with this stability trend, maintaining a consistent gap value for all molecules. The BN‐n‐acenes molecules possess a ground state with monoconfigurational character indicating their electronic stability. The low‐lying singlet excited states have charge transfer character, which proceeds from nitrogen to boron. 

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4. Functional dissection of the ARGONAUTE7 promoter

   https://doi.org/10.1002/pld3.102  

   Hoyer, J. Steen; Pruneda‐Paz, Jose L.; Breton, Ghislain; Hassert, Mariah A.; Holcomb, Emily E.; Fowler, Halley; Bauer, Kaylyn M.; Mreen, Jacob; Kay, Steve A.; Carrington, James C. (January 2019, Plant Direct)

   Abstract ARGONAUTES are the central effector proteins ofRNAsilencing which bind target transcripts in a smallRNA‐guided manner.Arabidopsis thalianahas 10ARGONAUTE(AGO) genes, with specialized roles inRNA‐directedDNAmethylation, post‐transcriptional gene silencing, and antiviral defense. To better understand specialization amongAGOgenes at the level of transcriptional regulation we tested a library of 1497 transcription factors for binding to the promoters ofAGO1,AGO10, andAGO7using yeast 1‐hybrid assays. A ranked list of candidateDNA‐bindingTFs revealed binding of theAGO7promoter by a number of proteins in two families: the miR156‐regulatedSPLfamily and the miR319‐regulatedTCPfamily, both of which have roles in developmental timing and leaf morphology. Possible functions forSPLandTCPbinding are unclear: we showed that these binding sites are not required for the polar expression pattern ofAGO7, nor for the function ofAGO7in leaf shape. NormalAGO7transcription levels and function appear to depend instead on an adjacent 124‐bp region. Progress in understanding the structure of this promoter may aid efforts to understand how the conservedAGO7‐triggeredTAS3pathway functions in timing and polarity. 

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5. Revisiting the N ( N  + 1)/2‐site s ‐type Gaussian charge model for permutationally invariant polynomial fitting of global molecular tensor surfaces

   https://doi.org/10.1002/qua.27102  

   Kudratov, Sophia A.; Kaledin, Martina; Kaledin, Alexey L. (February 2023, International Journal of Quantum Chemistry)

   Abstract The exact expressions for the dipole, quadrupole, and octupoles of a collection ofNpoint charges involve summations of corresponding tensors over theNsites weighted by their charge magnitudes. When the point charges are atoms (in a molecule) theN‐site formula is an approximation, and one must integrate over the electron density to recover the exact multipoles. In the present work we revisit theN(N + 1)/2‐site point charge density model of Hall (Chem. Phys. Lett.6, 501, 1973) for the purpose of fitting ab initio derived multipole moment hypersurfaces using permutationally invariant polynomials (PIP). We examine new approaches in PIP‐fitting procedures for the dipole, quadrupole, octupole moments, and polarizability tensor surfaces (DMS, QMS, OMS and PTS, respectively) for a non‐polar CCl₄and a polar CHCl₃and show that compared to the primitiveN‐site model theN(N + 1)/2‐site model appreciably improves the relative RMSE of the DMS and does much more substantially so, by an order of magnitude, for the corresponding ones of QMS and OMS. Training datasets are obtained by sampling potential energies up to 18 000 cm⁻¹above the global minima, generated by molecular dynamics simulations at the DFT B3LYP/aug‐cc‐pVDZ level of theory. 

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