[Genetic analysis of dense and erect panicle 2 allele DEP2-1388 and its application in hybrid rice breeding].

Using ethyl methanesulfonate (EMS) mutagenesis, we isolated an erect panicle mutant, R1338, from indica heavy-panicle restorer Shuhui498. Compared with wild type control, the mutant displayed dwarfism, erect and short panicle, short primary panicle branch, increased grain density, short grain length and increased grain thickness. In addition, the erect panicle architecture of R1388 resulted in significant decreased bending moment and increased resistance to panicle bending. Histocytological analysis indicated that the diameter of uppermost internode, cellulose content and lignin content play important roles in resistance to panicle bending. Genetic analysis revealed that the mutant phenotype was controlled by a semi-dominant nuclear gene. With resequencing and MutMap analysis strategy, we found that one SNP from A to G at the seventh exon of DEP2 resulted in the 928(th) amino acid substitution from arginine (AGG) to glycine (GGG) in R1338 mutant. Considering the phenotype of other dep2 mutants, the phenotype of R1338 was likely to be caused by the SNP in DEP2. The mutant R1338 and wild type were crossed with several sterile lines which respectively had different panicle types, the combinations generated from R1338 and curve panicle sterile lines showed semi-erect panicle, higher seed setting percentage and heterosis, and the combinations generated from R1388 and erect panicle sterile line with DEP1 showed erect panicle by gene additive effect. Moreover, the combinations with semi-erect panicle had superior light transmittance and stronger light intensity, which improved efficiency of light utilization to intermediate and subjacent leaves compared to the combinations with curved panicle. This study provides a good strategy to solve the problem of population density in three-line hybrid rice.

Preparation of agarose/chitosan composite supermacroporous monolithic cryogels for affinity purification of glycoproteins.

Supermacroporous agarose/chitosan composite monolithic (AC CM) cryogels were prepared for affinity purification of the major egg white glycoproteins, ovalbumin (OVA), and ovotransferrin (OVT). The supermacroporous AC CM cryogels were produced by cryocopolymerization of agarose/chitosan blend solutions using glutaraldehyde as the cross-linker. The 3-aminophenlyboronic acid ligand was immobilized by covalent binding to epoxy-group-coupled supermacroporous AC CM cryogels. The microstructure morphologies of these cryogels were analyzed by scanning electron microscopy. The supermacroporous AC CM cryogels contained a continuous interpenetrating polymer network matrix with interconnected pores of 10-100 µm in size. The composite cryogels offered high mechanical stability and had specific recognition for glycoproteins. The maximum binding capacity of OVA adsorption from aqueous solutions was 55.6 mg/g. The matrix could be reused 11 times without significant loss in OVA adsorption capacity. The recovery yields of OVA and OVT from egg white were estimated to be 89 and 93%, respectively.

The chromosome-level reference genome of Coptis chinensis provides insights into genomic evolution and berberine biosynthesis.

Coptis chinensis Franch, a perennial herb, is mainly distributed in southeastern China. The rhizome of C. chinensis has been used as a traditional medicine for more than 2000 years in China and many other Asian countries. The pharmacological activities of C. chinensis have been validated by research. Here, we present a de novo high-quality genome of C. chinensis with a chromosome-level genome of ~958.20 Mb, a contig N50 of 1.58 Mb, and a scaffold N50 of 4.53 Mb. We found that the relatively large genome size of C. chinensis was caused by the amplification of long terminal repeat (LTR) retrotransposons. In addition, a whole-genome duplication event in ancestral Ranunculales was discovered. Comparative genomic analysis revealed that the tyrosine decarboxylase (TYDC) and (S)-norcoclaurine synthase (NCS) genes were expanded and that the aspartate aminotransferase gene (ASP5) was positively selected in the berberine metabolic pathway. Expression level and HPLC analyses showed that the berberine content was highest in the roots of C. chinensis in the third and fourth years. The chromosome-level reference genome of C. chinensis provides important genomic data for molecular-assisted breeding and active ingredient biosynthesis.

Cross-section measurement for the 10B(n, alpha)7Li reaction at 4.0 and 5.0 MeV.

Cross-sections of the (10)B(n, alpha)(7)Li reaction were measured at En=4.0 and 5.0 MeV. A gridded ionization chamber (GIC) was used as charged particle detector. Neutrons were produced through the D(d, n)(3)He reaction with a deuterium gas target. Experiments were performed at the 4.5 MV Van de Graaff accelerator of Peking University. Cross-section data of the (238)U(n, f) reaction were employed as standard. The measured cross-sections of the (10)B(n, alpha)(7)Li reaction at 4.0 and 5.0 MeV are 211+/-17 and 169+/-14 mb, respectively, and they are compared with existing results of measurements and evaluations.

Reversible metal-induced emission and chromaticity switching in isostructural Ln-MOFs.

Several new isostructural lanthanide metal-organic frameworks {[Ln3(L)4(OH)(H2O)2]·DMAC}n (Ln = Tb (1), Gd (2), Eu (3), Gd0.81Tb0.10Eu0.09 (4) and Gd0.75Tb0.18Eu0.07 (5)) were designed and prepared. Excitingly, samples 1, 3, 4 and 5 showed reversible Al(3+)-induced chromaticity switching as well as reversible Fe(3+)-induced emission switching.

Metal-organic frameworks based on the [1,1':3',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid ligand: syntheses, structures and magnetic properties.

The solvothermal reactions of [1,1':3',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid (H4TPTA) with transition metal cations afforded five novel coordination polymers in the presence of three pyridine ligands (4,4'-bipy = 4,4'-bipyridine, 2,2'-bipy = 2,2'-bipyridine and phen = 1,10-phenanthroline), namely [M(TPTA)0.5(4,4'-bpy)0.5(H2O)2]n (M = Co for (1), Ni for (2)), {[Mn2(TPTA)(2,2'-bpy)H2O]·1.5H2O}n (3), and [M(H2TPTA)(phen)]n (M = Mn for (4), Co for (5)). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Polymers 1 and 2 are isomorphous and exhibit 3D 4-fold interpenetrated networks with the point Schläfli symbol of (4(2)·10(4)) (4·10(2)). Polymer 3 shows a 2D layer framework. Polymers 4 and 5 are also isomorphous and each displays a one-dimensional (1D) chain, which further forms a 2D supramolecular architecture via inter-chain π···π interactions. Moreover, variable-temperature magnetic susceptibilities of polymers 3-5 exhibit overall weak antiferromagnetic coupling between the adjacent M(II) ions.

Monolithic cryogels made of agarose-chitosan composite and loaded with agarose beads for purification of immunoglobulin G.

In order to obtain a novel absorbent with high adsorption capacity for the purification of immunoglobulin G (IgG), continuous supermacroporous agarose beads embedded agarose-chitosan composite monolithic cryogels (agarose-chitosan cryogels) were prepared by cryo-copolymerization of agarose-chitosan blend solutions with glutaraldehyde as the crosslinker in the presence of agarose beads. After coupling 2-mercaptopyridine onto divinylsulfone-activated matrix, the obtained cryogels were used for the purification of IgG. The microstructure morphologies of the cryogels were analyzed by scanning electron microscopy. The results showed that the obtained cryogels possess interconnected pores of 10-100 µm size. The specific surface area was 350 m(2)/g with maximum adsorption capacity of IgG 71.4 mg/g. The cryogels showed workable stability, and can be reused at least 15 times without significant loss in adsorption capacity. IgG purity after one-step purification from human plasma was monitored by electrophoresis and the average recovery was estimated to be 90%.

Measurement of cross sections for the 147Sm(n, alpha)144Nd reaction at 5.0 and 6.0 MeV.

Cross sections of the (147)Sm(n, alpha)(144)Nd reaction were measured at En=5.0 and 6.0MeV. A twin gridded ionization chamber was used as a charged particle detector and two large area (147)Sm(2)O(3) samples placed back to back were employed. Experiments were performed at the 4.5MV Van de Graaff accelerator of Peking University. Neutrons were produced through the D(d, n)(3)He reaction with a deuterium gas target. Absolute neutron flux was determined by a small (238)U fission chamber. Present cross-section data are compared with existing results of evaluations and measurements.