Mining Candidate Genes for Leaf Angle in Brassica napus L. by Combining QTL Mapping and RNA Sequencing Analysis.

Leaf angle (LA) is an important trait of plant architecture, and individuals with narrow LA can better capture canopy light under high-density planting, which is beneficial for increasing the overall yield per unit area. To study the genetic basis and molecular regulation mechanism of leaf angle in rapeseed, we carried out a series of experiments. Quantitative trait loci (QTL) mapping was performed using the RIL population, and seven QTLs were identified. Transcriptome analysis showed that the cell wall formation/biogenesis processes and biosynthesis/metabolism of cell wall components were the most enrichment classes. Most differentially expressed genes (DEGs) involved in the synthesis of lignin, xylan, and cellulose showed down-regulated expression in narrow leaf material. Microscopic analysis suggested that the cell size affected by the cell wall in the junction area of the stem and petiole was the main factor in leaf petiole angle (LPA) differences. Combining QTL mapping and RNA sequencing, five promising candidate genes BnaA01G0125600ZS, BnaA01G0135700ZS, BnaA01G0154600ZS, BnaA10G0154200ZS, and BnaC03G0294200ZS were identified in rapeseed, and most of them were involved in cell wall biogenesis and the synthesis/metabolism of cell wall components. The results of QTL, transcriptome analysis, and cytological analysis were highly consistent, collectively revealing that genes related to cell wall function played a crucial role in regulating the LA trait in rapeseed. The study provides further insights into LA traits, and the discovery of new QTLs and candidate genes is highly beneficial for genetic improvement.

Synthesis and antitumor mechanisms of a copper(II) complex of anthracene-9-imidazoline hydrazone (9-AIH).

A new anthracycline derivative, anthracene-9-imidazoline hydrazone (9-AIH), was synthesized and selected as an antitumor ligand to afford a copper(II) complex of 9-AIH, cis-[Cu(II)Cl2(9-AIH)] (1). Complex 1 was structurally characterized by IR, elemental analysis, ESI-MS and single crystal X-ray diffraction analysis. By MTT assay, it was revealed that 1 showed overall a higher in vitro cytotoxicity than 9-AIH towards a panel of human tumour cell lines, with IC50 values from 0.94­3.68 µM, in which the BEL-7404 cell line was the most sensitive to 1. By spectral analyses and gel electrophoresis, the DNA binding affinity of 9-AIH and 1 was determined. 9-AIH was suggested to bind with DNA in an intercalative mode, with a quenching constant of 1.04 × 10(4) M(−1) on the EB­DNA complex. While for 1, both intercalative and covalent binding modes were suggested. By flow cytometry, 1 was found to block the cell cycle of BEL-7404 cells in a dose-dependent mode, in which it induced the G2/M phase arrest at 0.5 µM and induced the S phase arrest at higher concentrations of 1.0 or 2.0 µM. From the cellular morphological observations under different fluorescence probe staining, a dose-dependent manner of 1 to induce cell apoptosis in the late stage was suggested. Comparatively, equivalent apoptotic cells, respectively, in the early and late stages were found when incubated with 2.0 µM of 9-AIH. The mitochondrial membrane potential measured by JC-1 staining and the ROS generation in cells detected using a DCFH-DA probe suggested that the cell apoptosis induced by 1 might undergo the ROS-related mitochondrial pathway. Accordingly, the mutant p53 expression was found to be suppressed and the caspase cascade (caspase-9/3) was consequently activated by 1. This action mechanism for 1 in the BEL-7404 cells was unique and was not found in the presence of 9-AIH under the same conditions, indicating their different antitumor mechanism. Furthermore, the in vivo acute toxicity of 1 tested on mice indicated that 1 should be a high cytotoxic antitumor agent, with the LD50 value in the range of 32­45 mg kg(−1), which is much higher than that of 9-AIH. From the above results, the central Cu(II) of 1 in the coordinated mode with 9-AIH was believed to play a key role in exerting both the high cytotoxicity and the effective antitumor mechanism.

Diaqua-[3,5-bis-(4-pyrid-yl)-1H-1,2,4-triazole-κN](pyridine-2,6-dicarboxyl-ato-κO,N,O)nickel(II).

In the title compound, [Ni(C(7)H(3)NO(4))(C(12)H(9)N(5))(H(2)O)(2)], the Ni(II) atom is coordinated in a distorted octa-hedral geometry by one N and two O atoms from a pyridine-2,6-dicarboxyl-ate ligand, one N atom from a 3,5-bis-(4-pyrid-yl)-1H-1,2,4-triazole ligand in equatorial positions and two water mol-ecules in axial positions. The crystal packing is consolidated by inter-molecular O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds.

9-[4-Hydr-oxy-3-(hydroxy-meth-yl)but-yl]guanine monohydrate.

In the mol-ecular structure of the title compound, also named penciclovir monohydrate, C(10)H(15)N(5)O(3)·H(2)O, the 4-hydr-oxy-3-hydroxy-methyl-but-1-yl group is connected to guanine through an N atom of the imidazole ring. Water mol-ecules stabilize the mol-ecular packing by forming O-H⋯O hydrogen bonds. A three-dimensional network is generated via inter-molecular N-H⋯N, N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonding.