A copper(I) thiocyanate-based photoresponsive semiconducting 2D coordination polymer.

A coordination polymer, [Cu(SCN)(iqi)]n (iqi = isoquinoline), containing copper(I) thiocyanate and a nitrogen-containing π-conjugated ligand, iqi, has been synthesized and its physical properties were evaluated. This coordination polymer has a two-dimensional (2D) sheet structure consisting of copper(I) thiocyanate and shows photoluminescence derived from 3MLCT and photoconductive properties.

Structural diversity of copper(I)-ethylene complexes with 2,4-bis(2-pyridyl)pyrimidine directed by anions.

The 3 : 1 reaction of [Cu(C2H4)n]ClO4 with 2,4-bis(2-pyridyl)pyrimidine (bpprd) in Me2CO under C2H4 afforded yellow prism crystals of the dinuclear Cu(I)-C2H4 complex [Cu2(bpprd)(η2-C2H4)2(ClO4)2] (1). The 3 : 1 reaction of [Cu(C2H4)n]NO3 with bpprd in Me2CO under C2H4 afforded yellow plate crystals of the tetranuclear Cu(I)-C2H4 complex [Cu4(bpprd)2(η2-C2H4)4(µ-NO3)2](NO3)2 (2). The 10 : 1 reaction of [Cu(C2H4)n]BF4 with bpprd in Me2CO under C2H4 afforded yellow plate crystals of the dinuclear Cu(I)-C2H4 complex [Cu2(bpprd)(η2-C2H4)2(BF4)]BF4 (3). The 3 : 1 reaction of [Cu(C2H4)n]BF4 with bpprd in Me2CO under C2H4 afforded red prism crystals of the polymeric Cu(I)-C2H4 complex {[Cu6(bpprd)4(η2-C2H4)2(µ-η2:η2-C2H4)(µ-BF4)2](BF4)4}n (4). The X-ray crystal structures of complexes 1-4 have been determined. The structural diversity of Cu(I)-C2H4 complexes bridged by bpprd with different anions was demonstrated. The 1D Cu(I)-bpprd/C2H4 coordination polymer 4 bridged by unusual µ-η2:η2-C2H4 and the µ-BF4- anion is of particular significance. Complex 1 exhibited relatively well-resolved 1H NMR signals of bpprd and C2H4 (δ = 4.97 ppm) in (CD3)2CO at 23 °C.

Transcriptomic analysis of developing seeds in a wheat (Triticum aestivum L.) mutant RSD32 with reduced seed dormancy.

Seed dormancy, a major factor regulating pre-harvest sprouting, can severely hinder wheat cultivation. Reduced Seed Dormancy 32 (RSD32), a wheat (Triticum aestivum L.) mutant with reduced seed dormancy, is derived from the pre-harvest sprouting tolerant cultivar, 'Norin61'. RSD32 is regulated by a single recessive gene and mutant phenotype expressed in a seed-specific manner. Gene expressions in embryos of 'Norin61' and RSD32 were compared using RNA sequencing (RNA-seq) analysis at different developmental stages of 20, 30, and 40 days after pollination (DAP). Numbers of up-regulated genes in RSD32 are equivalent in all developmental stages. However, down-regulated genes in RSD32 are more numerous on DAP20 and DAP30 than on DAP40. In central components affecting the circadian clock, homologues to the morning-expressed genes are expressed at lower levels in RSD32. However, higher expressions of homologues acting as evening-expressed genes are observed in RSD32. Homologues of Ca2+ signaling pathway related genes are specifically expressed on DAP20 in 'Norin61'. Lower expression is shown in RSD32. These results suggest that RSD32 mutation expresses on DAP20 and earlier seed developmental stages and suggest that circadian clock regulation and Ca2+ signaling pathway are involved in the regulation of wheat seed dormancy.

Correction: Dinuclear cobalt complexes with a redox active biphenyl bridging ligand [Co2(BP)(tqa)2](PF6)2 (H4BP = 4,4'-bis(3-tert-butyl-1,2-catechol), tqa = tris(2-quinolylmethyl)amine): structure and magnetic properties.

Correction for 'Dinuclear cobalt complexes with a redox active biphenyl bridging ligand [Co2(BP)(tqa)2](PF6)2 (H4BP = 4,4'-bis(3-tert-butyl-1,2-catechol), tqa = tris(2-quinolylmethyl)amine): structure and magnetic properties' by Yusaku Suenaga et al., Dalton Trans., 2021, DOI: .

Dinuclear cobalt complexes with a redox active biphenyl bridging ligand [Co2(BP)(tqa)2](PF6)2 (H4BP = 4,4'-bis(3-tert-butyl-1,2-catechol), tqa = tris(2-quinolylmethyl)amine): structure and magnetic properties.

The biscatechol, H4BP (4,4'-bis(3-tert-butyl-1,2-catechol)) that can directly connect two redox active catechol moieties was synthesized. Also, tris(2-pyridylmethyl)amine (tpa), bis(2-pyridylmethyl)(2-quinolylmethyl)amine (bpqa), (2-pyridylmethyl)bis(2-quinolyl methyl)amine (pbqa), and tris (2-quinolylmethyl)amine (tqa) were synthesized as terminal ligands of the tetracoordinated tripod. In total, five different dinuclear Co complexes were synthesized from H4BP with various terminal ligands as follows, [Co2(BP)(tpa)2](PF6)2 (1), [Co2(BP)(tpa)2](PF6)3 (2), [Co2(BP)(bpqa)2](PF6)2 (3), [Co2(BP)(pbqa)2](PF6)2 (4), and [Co2(BP)(tqa)2](PF6)2 (5). After a one-electron oxidation reaction of complex (1), complex (2), was isolated as a mixed valence state lsCoIII-[SQ-Cat]-lsCoIII, with an absorption intensity of about 1370 nm (intervalence charge transfer (IVCT) bands) in CH3CN solution. In addition, an investigation of the magnetic properties of the dinuclear Co complex (3) with SQUID showed that the χMT value gradually increased as the temperature increased from 280 to 380 K. Studies in the solid and solution states using electronic spectra, cyclic voltammetry and SQUID for the above complexes provide clear evidence for three different charge distributions: complexes (1) and (3) are CoIII-[Cat-Cat]-CoIII, complex (2) is CoIII-[Sq-Cat]-CoIII, complexes (4) and (5) are CoII-[Sq-Sq]-CoII. Of the five cobalt dinuclear complexes, only complex (3) shows evidence of the temperature dependence of the charge distribution, displaying a thermally induced valence tautomeric transition from the lsCoIII-[Cat-Cat]-lsCoIII to hsCoII-[Sq-Sq]-hsCoII in both solid and solution states. However, this valence tautomeric step is incomplete at 380 K, with the χMT value of hsCoII-[Sq-Sq]-hsCoII. This suggests that the steric hindrance of the quinolyl rings around the Co ion produces a coordination atmosphere that is weaker than that observed with pyridyl rings, which facilitates a change in the CoIII ions to CoII.

Transgenerational activation of an autonomous DNA transposon, Dart1-24, by 5-azaC treatment in rice.

KEY MESSAGE: Dart1-24, one of the 37 autonomous DNA transposon Dart1s, was heritably activated by the demethylation of the 5' region following 5-azaC treatment of rice seeds. Transposons are controlled by epigenetic regulations. To obtain newly activated autonomous elements of Dart1, a DNA transposon, in rice, seeds of a stable pale yellow leaf (pyl-stb) mutant caused by the insertion of nDart1-0, a nonautonomous element in OsClpP5, were treated with 5-azaC, a demethylating agent. In the 5-azaC-treated M1 plants, 60-70% of the plants displayed variegated pale yellow leaf (pyl-v) phenotype, depending on the concentration of 5-azaC used, suggesting that inactivated Dart1 might become highly activated by 5-azaC treatment and nDart1-0 was excised from OsClpP5 by the activated Dart1s. Although the M2 plants derived from most of these pyl-v plants showed stable pyl phenotypes, some variegated M1 plants generated pyl-v M2 progeny. These results indicated that most M1 pyl-v phenotypes at M1 were not heritable. Dart1-24, 1-27 and 1-28 were expressed in the M2 pyl-v plants, and mapping analysis confirmed that Dart1-24 was newly activated. Further, the transgenerational activation of Dart1-24 was demonstrated to be caused by the demethylation of nucleotides in its 5' region.

LARGE GRAIN Encodes a Putative RNA-Binding Protein that Regulates Spikelet Hull Length in Rice.

Grain size is a key determiner of grain weight, one of the yield components in rice (Oryza sativa). Therefore, to increase grain yield, it is important to elucidate the detailed mechanisms regulating grain size. The Large grain (Lgg) mutant, found in the nonautonomous DNA-based active rice transposon1 (nDart1)-tagged lines of Koshihikari, is caused by a truncated nDart1-3 and 355 bp deletion in the 5' untranslated region of LGG, which encodes a putative RNA-binding protein, through transposon display and cosegregation analysis between grain length and LGG genotype in F2 and F3. Clustered regularly interspaced short palindromic repeats/CRISPR-associated 9-mediated knockout and overexpression of LGG led to longer and shorter grains than wild type, respectively, showing that LGG regulates spikelet hull length. Expression of LGG was highest in the 0.6-mm-long young panicle and gradually decreased as the panicle elongated. LGG was also expressed in roots and leaves. These results show that LGG functions at the very early stage of panicle development. Longitudinal cell numbers of spikelet hulls of Lgg, knockout and overexpressed plants were significantly different from those of the wild type, suggesting that LGG might regulate longitudinal cell proliferation in the spikelet hull. RNA-Seq analysis of 1-mm-long young panicles from LGG knockout and overexpressing plants revealed that the expressions of many cell cycle-related genes were reduced in knockout plants relative to LGG-overexpressing plants and wild type, whereas some genes for cell proliferation were highly expressed in knockout plants. Taken together, these results suggest that LGG might be a regulator of cell cycle and cell division in the rice spikelet hull.

Establishment of nDart1-tagged lines of Koshihikari, an elite variety of rice in Japan.

To utilize a transposon-tagged mutant as a breeding material in rice, an endogenous DNA transposon, nDart1-0, was introduced into Koshihikari by successive backcrossing together with aDart1-27, an active autonomous element. The founder line for nDart1-tagged lines of Koshihikari carried nDart1-0 on chromosome 9 and transposed nDart1-12s on chromosomes 1 and 8 and nDart1-3 on chromosome 11. In nDart1-tagged lines, there were the most abnormal phenotypic mutants and many aberrant chlorophyll mutants at seedling stage. At mature stage, many semi-sterile mutants were observed. Dwarf, reduced culm number and lesion mimic mutants were also found. In total, 43.2% of the lines segregated some phenotypic mutants. Thus, the nDart1-tagged lines of Koshihikari are expected to be potentially useful for screening stress-tolerant mutants under abiotic or biotic stress conditions.

Easy sectioning of whole grain of rice using cryomicrotome.

To obtain a clear intact section of a ripened rice grain, which is suitable for biochemical and histological analysis, the Kawamoto method using a specific adhesive film was applied using a cryomicrotome. The longitudinal and sagittal sections were easily obtained together with the cross-section, and cell characteristics were clearly discerned in the ripened grain. It was demonstrated that the Kawamoto method is readily applicable for intact sectioning of hard tissue, including ripened grain. Intact section sampling may be useful for enzymatic analysis and transcriptomic analysis of plant tissue.

Crystal structure of a new mixed-metal coordin-ation polymer consisting of NiII piperidine-di-thio-carbamate and penta-nuclear CuI-I cluster units.

A new heterometallic CuI-NiII coordination polymer, poly[[tetra-µ3-iodido-µ2-iodido-bis-(µ3-piperidine-1-di-thio-carbamato)propio-nitrilepenta-copper(I)nickel(II)] chloro-form monosolvate], {[CuI5NiIII5(C6H10NS2)2(C3H5N)]·CHCl3} n , has been synthesized and structurally characterized. This coordination polymer consists of an NiII mononuclear unit of NiII(Pip-dtc)2 (Pip-dtc- is piperidine-1-di-thio-carbamate) and a penta-nuclear copper(I) cluster unit of Cu5I5(CH3CH2CN). The NiII ion, which lies on an inversion centre, is surrounded by four S atoms in a square-planar coordination geometry while all CuI ions have distorted tetra-hedral coordination geometries. In the penta-nuclear copper(I) cluster unit, a mirror plane passes through one CuI ion and three I ions. All the S atoms in NiII(Pip-dtc) are also coordinated by the CuI ions, forming an infinite zigzag chain structure along the b-axis direction. The chains are weakly connected by solvent CHCl3 mol-ecules via Cl⋯I [3.653 (1) Å] and Cl⋯S [3.4370 (1) Å] short-contact inter-actions.

Crystal Structure and Band-Gap Engineering of a Semiconducting Coordination Polymer Consisting of Copper(I) Bromide and a Bridging Acceptor Ligand.

A new semiconducting 3D coordination polymer, [Cu2Br2(ttz)] n (1), with an acceptor bridging ligand, 1,2,4,5-tetrazine (ttz), was synthesized. The complex shows large absorption bands extending to the near-IR region, indicating a small band gap in the coordination polymer. This complex shows higher conductivity than those of [CuBr(pyz)] n (2), including pyrazine (pyz) with a higher lowest unoccupied molecular orbital level. We performed density functional theory band calculations using the VASP program to understand the electronic states and conducting paths of the coordination polymer.

Case series report of navigation-based in vivo knee kinematics in total knee arthroplasty with a gradually reducing femoral radius design.

BACKGROUND: Simulations show that paradoxical anterior femoral slide in conventional dual radius total knee arthroplasty (TKA) is initiated by sudden reduction of the femoral radius from distal to posterior. Therefore, we hypothesized that a new TKA prosthesis design with a gradually reducing femoral radius may minimize the anterior slide in navigation-based in vivo knee kinematics. The purpose of this study was to compare the kinematics of TKA in vivo using a prosthesis with a gradually reducing radius, in comparison with the conventional dual radius design. METHODS: A retrospective case series report was performed for 12 knees with osteoarthritis using a CT-free navigation system. Six knees received TKA using a prosthesis with a gradually reducing femoral radius (Attune CR) and the other 6 knees underwent TKA using a conventional dual radius design (PFCΣ CR). Anterior-posterior (AP) displacement of the medial and lateral femoral condyles relative to the tibia, and kinematic patterns of the femur throughout the range of motion were compared between the groups. RESULTS: The average AP displacement in the Attune CR group indicated no paradoxical anterior movement of both condyles, and kinematic data showed a medial pivot pattern. In contrast, AP displacement in the PFCΣ CR group indicated that both condyles showed paradoxical anterior movement, and kinematically both condyles moved in the same manner, showing a parallel motion pattern. CONCLUSION: TKA using a prosthesis with a gradually reducing radius minimized paradoxical anterior slide in navigation-based in vivo knee kinematics.

Cultivable Methylobacterium species diversity in rice seeds identified with whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis.

Methylobacterium species are methylotrophic bacteria that widely inhabit plant surfaces. In addition to studies on methylotrophs as model organisms, research has also been conducted on their mechanism of plant growth promotion as well as the species-species specificity of plant-microbe interaction. We employed whole-cell matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (WC-MS) analysis, which enables the rapid and accurate identification of bacteria at the species level, to identify Methylobacterium isolates collected from the rice seeds of different cultivars harvested in Japan, Thailand, and Kenya. Rice seeds obtained from diverse geographical locations showed different communities of Methylobacterium species. We found that M. fujisawaense, M. aquaticum, M. platani, and M. radiotolerans are the most frequently isolated species, but none were isolated as common species from 18 seed samples due to the highly biased communities in some samples. These findings will contribute to the development of formulations containing selected species that promote rice growth, though it may be necessary to customize the formulations depending on the cultivars and farm conditions.

Gene expression of rice seeds surviving 13- and 20-month exposure to space environment.

Rice seeds were exposed outside of the international space station to assess the risk of space environment exposure on gene expression associated with seed germination. The germination percentages of the space-stored and ground-stored seeds exposed for 13 months were 48 and 96% respectively. Those for 20 months were 7 and 76%, respectively. Germination was defined 3 days after imbibition, except for the space-stored seeds exposed for 20 months, which germinated 5 days after imbibition. Subsequent RNA-seq analyses of the dry seeds, germinated seeds, and roots and shoots of seedlings revealed that the mutation rates of mRNA sequences were not significantly different between space-stored and ground-stored samples exposed for 13 months and 20 months. In all, 4 and 16 transcripts of glycolysis-related genes were increased in the germinated seeds after 13-month and 20-month exposure, respectively. Also, 2 and 39 transcripts of long-lived mRNA required for germination were decreased more than 2-fold in the dry seeds after 13-month and 20-month exposure, respectively. These results suggest that damage to long-lived mRNA in seeds by a space environment delays and reduces germination.

Amyloplast Membrane Protein SUBSTANDARD STARCH GRAIN6 Controls Starch Grain Size in Rice Endosperm.

Starch is a biologically and commercially important polymer of glucose. Starch is organized into starch grains (SGs) inside amyloplasts. The SG size differs depending on the plant species and is one of the most important factors for industrial applications of starch. There is limited information on genetic factors regulating SG sizes. In this study, we report the rice (Oryza sativa) mutant substandard starch grain6 (ssg6), which develops enlarged SGs in endosperm. Enlarged SGs are observed starting at 3 d after flowering. During endosperm development, a number of smaller SGs appear and coexist with enlarged SGs in the same cells. The ssg6 mutation also affects SG morphologies in pollen. The SSG6 gene was identified by map-based cloning and microarray analysis. SSG6 encodes a protein homologous to aminotransferase. SSG6 differs from other rice homologs in that it has a transmembrane domain. SSG6-green fluorescent protein is localized in the amyloplast membrane surrounding SGs in rice endosperm, pollen, and pericarp. The results of this study suggest that SSG6 is a novel protein that controls SG size. SSG6 will be a useful molecular tool for future starch breeding and applications.

Identification of QTLs for yield-related traits in RILs derived from the cross between pLIA-1 carrying Oryza longistaminata chromosome segments and Norin 18 in rice.

To improve rice yield, a wide genetic pool is necessary. It is therefore important to explore wild rice relatives. Oryza longistaminata is a distantly related wild rice relative that carries the AA genome. Its potential for improving agronomic traits is not well studied. Introgression line (pLIA-1) that carries Oryza longistaminata's chromosome segments, showed high performance in yield-related traits under non-fertilized conditions. Therefore, to illustrate Oryza longistaminata's potential for improving yield-related traits, RILs from the F1 of a cross between pLIA-1 and Norin 18 were developed and QTL analysis was done using the RAD-Seq method. In total, 36 QTLs for yield-related traits were identified on chromosomes 1, 2, 3, 5, 6, 7, 8, 10, and 11. Clusters of QTLs for strongly correlated traits were also identified on chromosomes 1, 3, 6, and 8. Phenotypic data from recombinant plants for chromosomes 1 and 8 QTL clusters revealed that the pLIA-1 genotype on chromosome 1 region was more important for panicle-related traits and a combination of pLIA-1 genotypes on chromosomes 1 and 8 showed a favorable phenotype under non-fertilized conditions. These results suggest that Oryza longistaminata's chromosome segments carry important alleles that can be used to improve yield-related traits of rice.

Light Inhibition of Shoot Regeneration Is Regulated by Endogenous Abscisic Acid Level in Calli Derived from Immature Barley Embryos.

Shoot regeneration in calli derived from immature barley embryos is regulated by light conditions during the callus-induction period. Barley cultivars Kanto Nijo-5 (KN5) and K-3 (K3) showed lower efficiency of shoot regeneration in a 16-h photoperiod during callus-induction than those in continuous darkness, whereas shoot regeneration was enhanced in cultures under a 16-h photoperiod in Golden Promise (GP) and Lenins (LN). These cultivars were classified as photo-inhibition type (KN5 and K3) or photo-induction type (GP and LN) according to their response to light. Contents of endogenous plant hormones were determined in calli cultured under a 16-h photoperiod and continuous darkness. In photo-inhibition type, higher accumulation of abscisic acid (ABA) was detected in calli cultured under a 16-h photoperiod, whereas calli showed lower levels of endogenous ABA in continuous darkness. However, cultivars of photo-induction type showed lower levels of ABA in calli cultured under both light conditions, similarly to photo-inhibition type in continuous darkness. Exogenous ABA inhibited the callus growth and shoot regeneration independent of light conditions in all cultivars. In photo-inhibition type, lower levels of endogenous ABA induced by ABA biosynthesis inhibitor, fluridone, reduced the photo-inhibition of shoot regeneration. Expression of ABA biosynthesis gene, HvNCED1, in calli was regulated by the light conditions. Higher expression was observed in calli cultured under a 16-h photoperiod. These results indicate that ABA biosynthesis could be activated through the higher expression of HvNCED1 in a 16-h photoperiod and that the higher accumulations of ABA inhibit shoot regeneration in the photo-inhibition type cultivars.

A gain-of-function Bushy dwarf tiller 1 mutation in rice microRNA gene miR156d caused by insertion of the DNA transposon nDart1.

A non-autonomous DNA transposon in rice, nDart1, is actively transposed in the presence of an autonomous element, aDart1, under natural conditions. The nDart1-promoted gene tagging line was developed using the endogenous nDart1/aDart1 system to generate various rice mutants effectively. While the dominant mutants were occasionally isolated from the tagging line, it was unclear what causes dominant mutations. A semidominant mutant, Bushy dwarf tiller1 (Bdt1), which has the valuable agronomic traits of multiple tillering and dwarfism, was obtained from the tagging line. Bdt1 mutant carried a newly inserted nDart1 at 38-bp upstream of transcription initiation site of a non-protein-coding gene, miR156d. This insertion caused an upstream shift of the miR156d transcription initiation site and, consequently, increased the functional transcripts producing mature microRNAs. These results indicate that the total amount of miR156d is controlled not only by transcript quantity but also by transcript quality. Furthermore, transgenic lines introduced an miR156d fragment that flanked the nDart1 sequence at the 5' region, suggesting that insertion of nDart1 in the gene promoter region enhances gene expression as a cis-element. This study demonstrates the ability of nDart1 to produce gain-of-function mutants as well as further insights into the function of transposable elements in genome evolution.

Geometrical Formation of Compound Starch Grains in Rice Implements Voronoi Diagram.

Starch forms transparent grains, called starch grains (SGs), in amyloplasts. One of the major morphological SG forms in Poaceae, called a compound SG, is formed by assemblies of small starch granules in an amyloplast. Starch granules assemble as a well-ordered structure; however, the mechanism that regulates this organization has not been identified. In this study, we examined how starch granules grow and converge into the final SG morphology. First, we found that the number of starch granules in an amyloplast is almost constant from the early developmental stage until endosperm maturity. Next, we quantitatively evaluated the geometrical similarities between starch granules and a Voronoi diagram, which is a mathematical tessellation of space based on the distance to a specific set of points in the space. The in silico growth simulation showed that the geometrical patterns of compound SGs resembling a Voronoi diagram is determined by physical interactions among the free-growing starch granules and the amyloplast envelope membrane. The geometrical similarity between compound SGs and a Voronoi diagram is likely a result of maximum loading and storage of starch in the amyloplast. The simulation described in this study provides a greater understanding of how compound SGs are formed and also has the potential to explain morphological variations of SGs.

Control of the Water Transport Activity of Barley HvTIP3;1 Specifically Expressed in Seeds.

Tonoplast intrinsic proteins (TIPs) are involved in the transport and storage of water, and control intracellular osmotic pressure by transporting material related to the water potential of cells. In the present study, we focused on HvTIP3;1 during the periods of seed development and desiccation in barley. HvTIP3;1 was specifically expressed in seeds. An immunochemical analysis showed that HvTIP3;1 strongly accumulated in the aleurone layers and outer layers of barley seeds. The water transport activities of HvTIP3;1 and HvTIP1;2, which also accumulated in seeds, were measured in the heterologous expression system of Xenopus oocytes. When they were expressed individually, HvTIP1;2 transported water, whereas HvTIP3;1 did not. However, HvTIP3;1 exhibited water transport activity when co-expressed with HvTIP1;2 in oocytes, and this activity was higher than when HvTIP1;2 was expressed alone. This is the first report to demonstrate that the water permeability of a TIP aquaporin was activated when co-expressed with another TIP. The split-yellow fluorescent protein (YFP) system in onion cells revealed that HvTIP3;1 interacted with HvTIP1;2 to form a heterotetramer in plants. These results suggest that HvTIP3;1 functions as an active water channel to regulate water movement through tissues during the periods of seed development and desiccation.