Identification and Functional Characterization of R3 MYB Transcription Factor Genes in Soybean

Shucai Wang,Jinsong Pang,Hongwei Xun,Zhibing Zhang,Yunxiao Zhou,Xueyan Qian,Yingshan Dong,Xianzhong Feng,Bao Liu 한국식물학회 2018 Journal of Plant Biology Vol.61 No.2

In Arabidopsis, trichome formation is regulatedby a MYB-bHLH-WD40 (MBW) transcriptional activatorcomplex, which can activate the expression of GLABRA2(GL2) and R3 MYB genes. GL2 is required for trichomeformation, whereas R3 MYBs inhibit trichome formation byblocking the formation of the MBW complex, thus inhibitingthe expression of GL2. By using the amino acid sequence of theArabidopsis R3 MYB transcription factor TRICHOMELESS1(TCL1) to BLAST the soybean (Glycine max) protein database,we found that there are a total of six R3 MYB genes insoybean, namely Glycine max TRICHOMELESS1 through 6(GmTCL1-GmTCL6). By generating transgenic plants, wefound that trichome formation in soybean plants overexpressingeach of the GmTCLs remained largely unchanged, and theexpression of putative GL1 and GL2 genes in the transgenicplants was unaffected. However, all the GmTCLs interactedwith GLABRA3 (GL3) in transfected Arabidopsis protoplasts,expression each of the GmTCLs in Arabidopsis inhibitedtrichome formation, and the expression levels of GL1 andGL2 were greatly reduced in the Arabidopsis transgenicplants. Moreover, phenotypic complementary analysis showedthat GmTCL1 is functionally equivalent to TCL1. Takentogether, these results suggest that GmTCLs are functionalR3 MYBs, however, they do not regulate trichome formationin soybean.

Spatially and temporally restricted expression of PtrMYB021 regulates secondary cell wall formation in Arabidopsis

Wei Wang,Eryang Li,Ilga Porth,Jin-Gui Chen,Shawn D. Mansfield,Carl J. Douglas,Shucai Wang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.1

Among the R2R3 MYB transcription factors that involve in the regulation of secondary cell wall formation in Arabidopsis, MYB46 alone is sufficient to induce the entire secondary cell wall biosynthesis program. PtrMYB021, the poplar homolog of MYB46, has been reported to regulate secondary cell wall formation when expressed in Arabidopsis. We report here that spatially and temporally restricted expression of PtrMYB021 is critical for its function in regulating secondary cell wall formation. By using quantitative RT-PCR, we found that PtrMYB021 was expressed primarily in xylem tissues. When expressed in Arabidopsis under the control of PtrCesA8, but not the 35S promoter, PtrMYB021 increased secondary cell wall thickness, which is likely caused by increased lignification as well as changes in cell wall carbohydrate composition. In consistent with this, elevated expression of lignin and cellulose biosynthetic genes were observed in the transgenic plants. When expressed in Arabidopsis protoplasts as fusion proteins to the Gal4 DNA binding domain, PtrMYB021 activated the reporter gene Gal4-GUS. In summary, our results suggest that PtrMYB021 is a transcriptional activator, and spatially and temporally restricted expression of PtrMYB021 in Arabidopsis regulates secondary cell wall formation by activating a subset of secondary cell wall biosynthesis genes.

A repressor motif-containing poplar R3 MYB-like transcription factor regulates epidermal cell fate determination and anthocyanin biosynthesis in Arabidopsis

Qingnan Hu,Li Yang,Shanda Liu,Limei Zhou,Xutong Wang,Wei Wang,Ling Cai,Xiuju Wu,Ying Chang,Shucai Wang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.5

Single-repeat R3 MYB transcription factors (R3 MYBs) regulate epidermal cell fate determination in Arabidopsis through a lateral inhibition mechanism. Previously we have shown that poplar R3 MYB genes regulate trichome formation when expressed in Arabidopsis. Here we report the identification and functional characterization of a poplar R3 MYB-like protein, Populus trichocarpa R3 MYB-LIKE1 (PtrRML1). So far all the MYB transcription factors identified have a highly conserved N-terminal DNA-binding domain composed of MYB repeats and a highly variable C-terminal domain. However, PtrRML1 has a single R3 MYB repeat at its C-terminal and an LxLxL repressor motif-containing N-terminal, and with amino acids about twice of that of the known R3 MYBs. PtrRML1 is localized in nuclear in transgenic Arabidopsis plants expressing PtrRML1-GFP. PtrRML1 repressed reporter gene expression in protoplasts, and it interacted with GL3 in plant cells. Expression of PtrRML1 in Arabidopsis resulted in glabrous phenotypes, increased number of root hairs, and decreased anthocyanin accumulation. Consist with these observation, the expression levels of some MBW component genes and some of their target genes involved in the regulation of epidermal cell fate determination and anthocyanin biosynthesis, including TRY, CPC, ETC1, GL1, GL2, DFR, UF3GT and TT8 were reduced in the transgenic plants.

Micro-texture design criteria for cemented carbide ball-end milling cutters

Shucai Yang,Tianjiao Wang,Wei Ren,Shuai Su 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

Given the serious work hardening phenomenon, high chemical activity, severe tool wear, and poor workpiece surface quality during the cutting of titanium alloys, placing micro-texture on the tool surface decreases the tool-chip contact area and friction and plays the role of wear resistance and friction reduction. In order to improve the cutting performance of cutting tools, the present study examins the effect of micro-texture parameters of a cemented carbide ball-end milling cutter on cutting force, tool wear, and workpiece surface roughness and establishes a regression analysis model via regression analysis. We consider the cutting performance of a cemented carbide micro-texture ball-end milling cutter as an evaluation standard. A genetic algorithm is applied to the multi-objective optimization of micro-texture parameters, and a regression analysis model of micro-texture design criteria is established. This provides a standardised reference to select standard micro-texture parameters in the design and preparation of a cemented carbide micro-texture ball-end milling cutter.

Collapse risk evaluation method on Bayesian network prediction model and engineering application

WANG, Jing,LI, Shucai,LI, Liping,SHI, Shaoshuai,XU, Zhenhao,LIN, Peng Techno-Press 2017 Advances in computational design Vol.2 No.2

Collapse was one of the typical common geological hazards during the construction of tunnels. The risk assessment of collapse was an effective way to ensure the safety of tunnels. We established a prediction model of collapse based on Bayesian Network. 76 large or medium collapses in China were analyzed. The variable set and range of the model were determined according to the statistics. A collapse prediction software was developed and its veracity was also evaluated. At last the software was used to predict tunnel collapses. It effectively evaded the disaster. Establishing the platform can be subsequent perfect. The platform can also be applied to the risk assessment of other tunnel engineering.

An elasto-plastic damage constitutive model for jointed rock mass with an application

Wang, Hanpeng,Li, Yong,Li, Shucai,Zhang, Qingsong,Liu, Jian Techno-Press 2016 Geomechanics & engineering Vol.11 No.1

A forked tunnel, as a special complicated underground structure, is composed of big-arch tunnel, multi-arch tunnel, neighborhood tunnels and separate tunnels according to the different distances between two separate tunnels. Due to the complicated process of design and construction, surrounding jointed rock mass stability of the big-arch tunnel which belongs to the forked tunnel during excavation is a hot issue that needs special attentions. In this paper, an elasto-plastic damage constitutive model for jointed rock mass is proposed based on the coupling method considering elasto-plastic and damage theories, and the irreversible thermodynamics theory. Based on this elasto-plastic damage constitutive model, a three dimensional elasto-plastic damage finite element code (D-FEM) is implemented using Visual Fortran language, which can numerically simulate the whole excavation process of underground project and perform the structural stability of the surrounding rock mass. Comparing with a popular commercial computer code, three dimensional fast Lagrangian analysis of continua (FLAC3D), this D-FEM has advantages in terms of rapid computing process, element grouping function and providing more material models. After that, FLAC3D and D-FEM are simultaneously used to perform the structural stability analysis of the surrounding rock mass in the forked tunnel considering three different computing schemes. The final numerical results behave almost consistent using both FLAC3D and D-FEM. But from the point of numerically obtained damage softening areas, the numerical results obtained by D-FEM more closely approach the practical behaviors of in-situ surrounding rock mass.

Developing brittle transparent materials with 3D fractures and experimental study

Jing Wang,Shucai Li,Weishen Zhu,Li-Ping Li 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.2

The fracture propagation mechanism and fractured rock mass failure mechanism were important research in geotechnical engineering field. Many failures and instability in geotechnical engineering were related on fractures propagation, coalescence and interaction in rock mass under the external force. Most of the current research were limited to two-dimensional for the brittleness and transparency of three-dimensional fracture materials couldn't meet the requirements of the experiment. New materials with good transparent and brittleness were developed by authors. The making method of multi fracture specimens were established and made molds that could be reused. The tension-compression ratio of the material reached above 1/6 in normal temperature. Uniaxial and biaxial loading tests of single and double fracture specimens were carried out. Four new fractures were not found in the experiment of two-dimensional fractures such as the fin shaped crack, wrapping wing crack and petal crack and anti-wing crack. The relationship between stress and strain of the specimens were studied. The specimens with the load had experienced four stages of deformation and the process of the fracture propagation was clearly seen in each stage. The expansion characteristics of the fractured specimens were more obvious than the previous research.

Study on anchorage effect on fractured rock

Jing Wang,Shucai Li,Li-Ping Li,Weishen Zhu,Qian-qing Zhang,Shu-Guang Song 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.6

The effects of anchor on fractured specimens in splitting test are simulated by DDARF method, the results of which are compared with laboratory test results. They agree well with each other. The paper contents also use the laboratory model test. The main research objects are three kinds of specimens, namely intact specimens, jointed specimens and anchored-jointed specimens. The results showed that with the joint angle increased, the weakening effects of jointed rock mass are more obvious. At these points, the rock bolts' strengthening effects on the specimens have become more significant. There is a significant impact on the failure modes of rock mass by the joint and the anchorage.

Research on Quick-freezing Device with Ultralow Temperature Water Medium under Negative Pressure and Quick-freezing Method

Li Shuo,Wang Shucai,Cheng Fang,Xia Gaobing 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.8

This paper puts forward a quick-freezing method by putting the ultralow temperature medium into a negative pressure. Through the experiment, it indicated the speed and quality to refrigerating water under the condition of negative pressure. Based on that, it designed a quick-freezing device. Meanwhile this paper researched on how to quick-freeze products in bags by adopting this device. After being testified by the experiment, it proved that this device had improved the quick-freezing efficiency and the refrigerating effect.

R2R3 MYB transcription factor PtrMYB192 regulates flowering time in Arabidopsis by activating FLOWERING LOCUS C

Shanda Liu,Xiaoping Wang,Eryang Li,Carl J. Douglas,Jin-Gui Chen,Shucai Wang 한국식물학회 2013 Journal of Plant Biology Vol.56 No.4

R2R3 MYB transcription factors regulate multiple aspects of plant growth and development. Here we report the identification of PtrMYB192, a Populus R2R3 MYB transcription factor, as a negative regulator of flowering time. By using quantitative RT-PCR, we found that PtrMYB192, but not its closely homologous gene PtrMYB028, is highly expressed in mature leaves in Populus. Heterologously expression of PtrMYB192 under control of 35S promoter in Arabidopsis resulted in late flowering phenotypes under both long and short day conditions, indicating that PtrMYB192 controls flowering time independent of the photoperiod pathway. Domain swapping experiment showed that neither PtrMYB028DB-192AD nor PtrMYB192DB-028AD affected flowering time when heterologously expressed in Arabidopsis. However, when recruit to the promoter of a GAL4-GUS reporter gene by a GAL4 DNA binding domain in Arabidopsis protoplasts, both of PtrMYB028DB-192AD and PtrMYB192DB-028AD activated the reporter gene. Quantitative RT-PCR results showed an elevated expression of the floral repressor gene FLOWERING LOCUS C (FLC), but not the flowering-promoting gene CONSTANS (CO) in PtrMYB192 transgenic plants. Taken together, these results suggest that PtrMYB192 is a transcription activator that negatively regulating flowering time in Arabidopsis by activating FLC and possible other genes, and that both R2R3 DNA binding domain and activation domain maybe required for its full function.