Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination ...Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination and post-germinative growth through the PYR1/PYL/RCAR ABA receptors and PP2C co-receptors,the phytohormone abscisic acid(ABA)prevents premature germination and seedling growth under unfavorable conditions.However,little is known about how the ABA-mediated inhibition of seed germination and seedling establishment is thwarted.Here,we report that ABA Signaling Terminator(ABT),a WD40 protein,efficiently switches off ABA signaling and is critical for seed germination and seedling establishment.ABT is induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner.Overexpression of ABT promotes seed germination and seedling greening in the presence of ABA,whereas knockout of ABT has the opposite effect.We found that ABT interacts with the PYR1/PYL/RCAR and PP2C proteins,interferes with the interaction between PYR1/PYL4 and ABI1/ABI2,and hampers the inhibition of ABI1/ABI2 by ABA-bound PYR1/PYL4,thereby terminating ABA signaling.Taken together,our results reveal a core mechanism of ABA signaling termination that is critical for seed germination and seedling establishment in Arabidopsis.展开更多
MXene is a variety of new two-dimensional(2D)materials with early transition metal carbides,nitrides,and carbonitrides.Quantum chemical studies have been carried out on the geometries,electronic structures,stability a...MXene is a variety of new two-dimensional(2D)materials with early transition metal carbides,nitrides,and carbonitrides.Quantum chemical studies have been carried out on the geometries,electronic structures,stability and catalytic properties of a non-noble metal single-atom catalyst(SAC)with single Co atom anchored on MXene materials of Mo_(2)CS_(2).The Co adatom anchored on top of the Mo atom of this MXene is found to be rather stable,and this SAC is appropriate for CO oxidation.The charge transfers from the surface to the adsorbed CO and O2 play a significant role in the activation of these molecules on Co_(1)/Mo_(2)CS_(2).With this catalyst,the Eley-Rideal(ER),Langmuir-Hinshelwood(LH),and Termolecular Eley-Rideal(TER)mechanisms are explored for CO oxidation.We find that,while all the three mechanisms are feasible at low temperature,Co_(1)/Mo_(2)CS_(2) possesses higher catalytic activity for CO oxidation through the TER mechanism that features an intriguing OC(OO)CO intermediate(IM)adsorbed on Co single atom.The calculated activation energy barriers of the rate-limiting step are 0.67 eV(TER),0.78 eV(LH)and 0.88 eV(ER),respectively.The present study illustrates that it is promising to develop and design low-cost,non-noble metal SACs using MXene types of 2D materials.展开更多
The title compound, Pd4Cl2, has been synthesized and structurally characterized. It crystallizes in orthorhombic, Pna2(1) space group , with Mr=481.79(C4H16Cl2N8PdS4), a=12.943(3), b=8.283(2), c=15.148(3)? , V=1623.9(...The title compound, Pd4Cl2, has been synthesized and structurally characterized. It crystallizes in orthorhombic, Pna2(1) space group , with Mr=481.79(C4H16Cl2N8PdS4), a=12.943(3), b=8.283(2), c=15.148(3)? , V=1623.9(6)? 3, Z=4. The Pd? ion has an square planar geometry, and is coordinated by four S atom donors from four thiourea molecules. The two Cl- anions found in the apical position balance the charge. In the solid state, the title compound forms three dimensional network structures through hydrogen bonds. The intermolecular hydrogen bonds connect the {Pd4}2+ and chloride ion to contribute to the stability of the structure. CCDC: 193379.展开更多
The title compound,{[n-Bu 2 Sn(O 2 CCH 2 CS 2 NC 4 H 8 )] 2 O} 2 ,has been synthesized by the reaction of(tetrahydro-pyrrodithiolocarbamoylthio)acetic acid with the di-n-bubyltin oxide in1∶1molar ratio.The complex ha...The title compound,{[n-Bu 2 Sn(O 2 CCH 2 CS 2 NC 4 H 8 )] 2 O} 2 ,has been synthesized by the reaction of(tetrahydro-pyrrodithiolocarbamoylthio)acetic acid with the di-n-bubyltin oxide in1∶1molar ratio.The complex has been characterized by elemental analysis,IR and NMR.The crystal structure of it has been determined by X-ray single crystal diffraction.And the results showed that the crystal belongs to triclinic system with space group P1and some crystal parameters:a=1.2202(9)nm,b=1.3158(10)nm,c=1.3804(10)nm,α =111.215(9)° ,β =99.357(9)° ,γ =96.075(10)°,V=2.006(2)nm 3 ,Z=1,F(000)=908,μ =1.489mm -1 ,D c =1.474g · cm -3 ,R 1 =0.0375,wR 2 =0.0839.The complex has a centrosymmetric dimer structure mode with a four-membered central endo-cyclic Sn 2 O 2 unit in which two bridged oxygen atoms both connect with an exo-cyclic tin atom which has a distorted octahedron.Each of the endo-cyclic tin atoms exhibits a distorted trigonal bipyramid coordination geometry with an additional weak coordination carboxylate oxygen.Four carboxylate ligands are divided into two types.And two of them are bidentate and connecting to each of exo-cyclic tin atoms by using both oxygen atoms,whereas the others bridge to each pair of exo-and endo-cyclic tin atoms utilizing one oxygen atom only.CCDC:220513.展开更多
基金supported by the National Key Research and Development Program of China(2016YFA0500503)the Fundamental Research Funds for the Central Universities(2662018PY075)+1 种基金the National Natural Science Foundation of China(31730066,91540112)the Huazhong Agricultural University's Scientific and Technological Self-innovation Foundation(2015RC014).
文摘Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination and post-germinative growth through the PYR1/PYL/RCAR ABA receptors and PP2C co-receptors,the phytohormone abscisic acid(ABA)prevents premature germination and seedling growth under unfavorable conditions.However,little is known about how the ABA-mediated inhibition of seed germination and seedling establishment is thwarted.Here,we report that ABA Signaling Terminator(ABT),a WD40 protein,efficiently switches off ABA signaling and is critical for seed germination and seedling establishment.ABT is induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner.Overexpression of ABT promotes seed germination and seedling greening in the presence of ABA,whereas knockout of ABT has the opposite effect.We found that ABT interacts with the PYR1/PYL/RCAR and PP2C proteins,interferes with the interaction between PYR1/PYL4 and ABI1/ABI2,and hampers the inhibition of ABI1/ABI2 by ABA-bound PYR1/PYL4,thereby terminating ABA signaling.Taken together,our results reveal a core mechanism of ABA signaling termination that is critical for seed germination and seedling establishment in Arabidopsis.
基金the National Natural Science Foundation of China(21590792,91426302,and 21433005)Guangdong Provincial Key Laboratory of Catalysis(2020B121201002)+1 种基金the National Science Basic Research Program of Shaanxi Province(2019JM-226)the financial and technical support from the Research Center for Advanced Materials Science(RCAMS)at King Khalid University through the Grant(RCAMS/KKU/014-20)。
文摘MXene is a variety of new two-dimensional(2D)materials with early transition metal carbides,nitrides,and carbonitrides.Quantum chemical studies have been carried out on the geometries,electronic structures,stability and catalytic properties of a non-noble metal single-atom catalyst(SAC)with single Co atom anchored on MXene materials of Mo_(2)CS_(2).The Co adatom anchored on top of the Mo atom of this MXene is found to be rather stable,and this SAC is appropriate for CO oxidation.The charge transfers from the surface to the adsorbed CO and O2 play a significant role in the activation of these molecules on Co_(1)/Mo_(2)CS_(2).With this catalyst,the Eley-Rideal(ER),Langmuir-Hinshelwood(LH),and Termolecular Eley-Rideal(TER)mechanisms are explored for CO oxidation.We find that,while all the three mechanisms are feasible at low temperature,Co_(1)/Mo_(2)CS_(2) possesses higher catalytic activity for CO oxidation through the TER mechanism that features an intriguing OC(OO)CO intermediate(IM)adsorbed on Co single atom.The calculated activation energy barriers of the rate-limiting step are 0.67 eV(TER),0.78 eV(LH)and 0.88 eV(ER),respectively.The present study illustrates that it is promising to develop and design low-cost,non-noble metal SACs using MXene types of 2D materials.
文摘The title compound, Pd4Cl2, has been synthesized and structurally characterized. It crystallizes in orthorhombic, Pna2(1) space group , with Mr=481.79(C4H16Cl2N8PdS4), a=12.943(3), b=8.283(2), c=15.148(3)? , V=1623.9(6)? 3, Z=4. The Pd? ion has an square planar geometry, and is coordinated by four S atom donors from four thiourea molecules. The two Cl- anions found in the apical position balance the charge. In the solid state, the title compound forms three dimensional network structures through hydrogen bonds. The intermolecular hydrogen bonds connect the {Pd4}2+ and chloride ion to contribute to the stability of the structure. CCDC: 193379.
文摘The title compound,{[n-Bu 2 Sn(O 2 CCH 2 CS 2 NC 4 H 8 )] 2 O} 2 ,has been synthesized by the reaction of(tetrahydro-pyrrodithiolocarbamoylthio)acetic acid with the di-n-bubyltin oxide in1∶1molar ratio.The complex has been characterized by elemental analysis,IR and NMR.The crystal structure of it has been determined by X-ray single crystal diffraction.And the results showed that the crystal belongs to triclinic system with space group P1and some crystal parameters:a=1.2202(9)nm,b=1.3158(10)nm,c=1.3804(10)nm,α =111.215(9)° ,β =99.357(9)° ,γ =96.075(10)°,V=2.006(2)nm 3 ,Z=1,F(000)=908,μ =1.489mm -1 ,D c =1.474g · cm -3 ,R 1 =0.0375,wR 2 =0.0839.The complex has a centrosymmetric dimer structure mode with a four-membered central endo-cyclic Sn 2 O 2 unit in which two bridged oxygen atoms both connect with an exo-cyclic tin atom which has a distorted octahedron.Each of the endo-cyclic tin atoms exhibits a distorted trigonal bipyramid coordination geometry with an additional weak coordination carboxylate oxygen.Four carboxylate ligands are divided into two types.And two of them are bidentate and connecting to each of exo-cyclic tin atoms by using both oxygen atoms,whereas the others bridge to each pair of exo-and endo-cyclic tin atoms utilizing one oxygen atom only.CCDC:220513.
