Identification of a tomato UDP-arabinosyltransferase for airborne volatile reception

植物間コミュニケーションの仕組みを解明 --受容した香りを防御物質に変える遺伝子発見--. 京都大学プレスリリース. 2023-02-28.Volatiles from herbivore-infested plants function as a chemical warning of future herbivory for neighboring plants. (Z)-3-Hexenol emitted from tomato plants infested by common cutworms is taken up by uninfested plants and converted to (Z)-3-hexenyl β-vicianoside (HexVic). Here we show that a wild tomato species (Solanum pennellii) shows limited HexVic accumulation compared to a domesticated tomato species (Solanum lycopersicum) after (Z)-3-hexenol exposure. Common cutworms grow better on an introgression line containing an S. pennellii chromosome 11 segment that impairs HexVic accumulation, suggesting that (Z)-3-hexenol diglycosylation is involved in the defense of tomato against herbivory. We finally reveal that HexVic accumulation is genetically associated with a uridine diphosphate-glycosyltransferase (UGT) gene cluster that harbors UGT91R1 on chromosome 11. Biochemical and transgenic analyses of UGT91R1 show that it preferentially catalyzes (Z)-3-hexenyl β-D-glucopyranoside arabinosylation to produce HexVic in planta

MAGNETIC ANISOTROPY DISTRIBUTED NEAR THE SURFACE OF AMORPHOUS RIBBONS

Magnetic anisotropy in an amorphous ribbon of Fe_Ni_P_B_6, Allied Chemical Metglas 2826, has been studied. Magnetic domain structures and the in-plane anisotropy were measured as a function of the depth from the ribbon surface by a powder technique, transmission electron microscopy and a torque method. The data have an obvious connection with the surface topography of the ribbon that is introduced in the melt and quench process. Groups of fine domains, which originate from the perpendicular anisotropy, cover a large part of the as-quenched surface. They diminish rapidly with depth. In accordance with the disappearance of fine domains the in-plane anisotropy also decreases. It shows a maximum, an order of 10^5 erg/cc, at the surface and decreases one or two orders smaller at the center of the ribbon. These results suggest an inhomogeneous distribution of internal stress that is introduced at the quenching process

Engineering study on lithium isotope separation by ion exchange chromatography

We have been studying the lithium isotope separation by ion exchange chromatography for the engineering development. We performed the lithium isotope separation experiments by chromatography. From the results, we estimated the migration lengths required to obtain the 20 %, 50 %, and 90 % enriched lithium-6, the required lengths are 340, 1600, and 5800 m, respectively. We studied the detection methods of lithium adsorption band boundary in order to design the circular type chromatographic equipment, which type equipment is required for the industrial plant. Based on these investigations, we designed the automatic circular type chromatographic equipment with the boundary interface detector and manufactured the prototype equipment

Keto–Enol Tautomeric Equilibrium of Acetylacetone Solution Confined in Extended Nanospaces

We aim to clarify the effects of size confinement, solvent, and deuterium substitution on keto–enol tautomerization of acetylacetone (AcAc) in solutions confined in 10–100 nm spaces (<i>i.e.</i>, extended nanospaces) using ¹H NMR spectroscopy. The keto–enol equilibrium constants of AcAc (<i>K</i>_EQ = [keto]/[enol]) in various solvents confined in extended nanospaces of 200–3000 nm were examined using the area ratios of −CH₃ peaks in keto to enol forms. The results showed that the keto form of AcAc in hydrogen-bonded solvents such as water and ethanol increased drastically with decreasing space sizes below about 500 nm, but the size confinement did not induce equilibrium shifts in aprotic solvents such as DMSO. The magnitudes of <i>K</i>_EQ enhancement were well correlated with solvent proton donicity. It followed from the determination of thermodynamic parameters that the stabilization of intermolecular interactions between protons in water and carbonyl oxygen (CO) in the keto form of AcAc were promoted by size-confinement, and that the keto form could be energetically and structurally favored in extended nanospaces <i>vis-à-vis</i> the bulk space. Furthermore, the measurements of deuterium dependence of the <i>K</i>_EQ values verified that the nanoconfinement-induced shifts of keto–enol tautomerization of AcAc are attributable to high proton mobility via a proton hopping mechanism of the confined water

Synthesis and Evaluation of Thermoresponsive Boron-Containing Poly(N-isopropylacrylamide) Diblock Copolymers for Self-Assembling Nanomicellar Boron Carriers

Development of new boron nanocarriers has been a crucial issue to be solved for advancing boron neutron capture therapy (BNCT) as an effective radiation treatment for cancers. The present study aimed to create a novel double-thermoresponsive boron-containing diblock copolymer based on poly(N-isopropylacrylamide) [poly(NIPAAm)], which exhibits two-step phase transitions (morphological transitions) at the temperature region below human body temperature. The boronated diblock copolymer considerably concentrates boron atoms into the water-dispersible (i.e., intravenous-administration possible) nanomicelles self-assembled by the first phase transition, and furthermore the properly controlled size and hydrophobicity of the second phase-transitioned nanoparticles are expected to make a significant contribution to the selective delivery and long-term retention of boron atoms into tumor tissues. Here we present the detailed synthesis of the strategic NIPAAm-based diblock copolymer with 3-acrylamidophenylboronic acid (PBA), i.e., poly(NIPAAm-block-NIPAAm-co-PBA), through a reversible addition-fragmentation chain transfer polymerization. Furthermore, the stepwise phase transition behavior of the obtained boronic-acid diblock copolymers was characterized in detail by temperature-variable 1H and 11B-nuclear magnetic resonance spectroscopy. The phase-transition-induced molecular structural changes, including the structural compositions and sizes of nanomicelles and nanoparticles, are also discussed here