Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 34

  • Signal Transduction Pathways in Plants for Resistance against Pathogens

    Liu, Jian-Zhong   Lam, Hon-Ming  

    Download Collect
  • Hetero-trimeric G protein signaling in plant immunity

    Zhong, Chen-Li   Zhang, Chi   Liu, Jian-Zhong  

    Download Collect
  • The MAPK Kinase Kinase GmMEKK1 Regulates Cell Death and Defense Responses

    Xu, Hui-Yang   Zhang, Chi   Li, Zhen-Chao   Wang, Zhi-Rong   Jiang, Xu-Xu   Shi, Ya-Fei   Tian, Sheng-Nan   Braun, Edward   Mei, Yu   Qiu, Wen-Li   Li, Sen   Wang, Bo   Xu, Juan   Navarre, Duroy   Ren, Dongtao   Cheng, Ninghui   Nakata, Paul A.   Graham, Michelle A.   Whitham, Steven A.   Liu, Jian-Zhong  

    MAPK signaling pathways play critical roles in plant immunity. Here, we silenced multiple genes encoding MAPKs using virus-induced gene silencing mediated by Bean pod mottle virus to identify MAPK genes involved in soybean (Glycine max) immunity. Surprisingly, a strong hypersensitive response (HR) cell death was observed when soybean MAPK KINASE KINASE1 (GmMEKK1), a homolog of Arabidopsis (Arabidopsis thaliana) MEKK1, was silenced. The HR was accompanied by the overaccumulation of defense signaling molecules, salicylic acid (SA) and hydrogen peroxide. Genes involved in primary metabolism, translation/transcription, photosynthesis, and growth/development were down-regulated in GmMEKK1-silenced plants, while the expression of defense-related genes was activated. Accordingly, GmMEKK1-silenced plants were more resistant to downy mildew (Peronospora manshurica) and Soybean mosaic virus compared with control plants. Silencing GmMEKK1 reduced the activation of GmMPK6 but enhanced the activation of GmMPK3 in response to flg22 peptide. Unlike Arabidopsis MPK4, GmMPK4 was not activated by either flg22 or SA. Interestingly, transient overexpression of GmMEKK1 in Nicotiana benthamiana also induced HR. Our results indicate that GmMEKK1 plays both positive and negative roles in immunity and appears to differentially activate downstream MPKs by promoting GmMPK6 activation but suppressing GmMPK3 activation in response to flg22. The involvement of GmMPK4 kinase activity in cell death and in flg22- or SA-triggered defense responses in soybean requires further investigation.
    Download Collect
  • Pore Characteristics and Slurryability of Coal Blends

    Zhu, Jie-Feng   Wang, Jie   Liu, Jian-Zhong   Cheng, Jun   Wang, Zhi-Hua   Zhou, Jun-Hu   Cen, Ke-Fa  

    The pore characteristics and slurryability of two coal blends between Shigang anthracite coal and Huangling bituminous coal (SG/HL), and Guizhou anthracite coal and Xiaotun lean coal (GZ/XT), respectively, were investigated. The fractal dimensions of coal were calculated in the two regions of P/P-0 < 0.45 and P/P-0 > 0.45 and defined as D, and D-2, respectively. Upon an increase in the blending ratio of parent coal with smaller BET surface area (SBET) and total pore volume (TPV), the S-BET and TPV of coal blends monotonously decreased. D-1 was mainly related to the Smeso/macro(10-220 nm)/S-total and mineral phase within coal while D-2 was closely affected by the Vmeso(2-10 nm)/V-total. D-1 of SG/HL coal blends had no apparent linear correlation with the pore structure parameters whereas I), of GZ/XT coal blends changed linearly with the pore structure parameters. Both D-2 of SG/HL coal blends and that of GZ/XT coal blends changed linearly with the pore structure parameters. The slurry quality of coal water slurry (CWS) prepared from coal blends is comprehensively affected by the physicochemical properties and blending ratio of parent coals. Therefore, the maximum solid loading (MSL) and water separation ratio (WSR) of CWS prepared from coal blends do not always change linearly with the blending ratio of parent coal.
    Download Collect
  • Slurry characteristics and mechanism analysis of petroleum coke-coal water slurry

    Wang, Shuang-Ni   Liu, Jian-Zhong   Wang, Yi   Li, Ning   Cen, Ke-Fa  

    Download Collect
  • Positive and Negative Roles for Soybean MPK6 in Regulating Defense Responses

    Liu, Jian-Zhong   Braun, Edward   Qiu, Wen-li   Shi, Ya-Fei   Marcelino-Guimar?es, Francismar C.   Navarre, Duroy   Hill, John H.   Whitham, Steven A.  

    It has been well established that MPK6 is a positive regulator of defense responses in model plants such as Arabidopsis and tobacco. However, the functional importance of soybean MPK6 in disease resistance has not been investigated. Here, we showed that silencing of GmMPK6 in soybean using virus-induced gene silencing mediated by Bean pod mottle virus (BPMV) caused stunted growth and spontaneous cell death on the leaves, a typical phenotype of activated defense responses. Consistent with this phenotype, expression of pathogenesis-related (PR) genes and the conjugated form of salicylic acid were significantly increased in GmMPK6-silenced plants. As expected, GmMPK6-silenced plants were more resistant to downy mildew and Soybean mosaic virus compared with vector control plants, indicating a negative role of GmMPK6 in disease resistance. Interestingly, overexpression of GmMPK6, either transiently in Nicotiana benthamiana or stably in Arabidopsis, resulted in hypersensitive response (HR)-like cell death. The HR-like cell death was accompanied by increased PR gene expression, suggesting that GmMPK6, like its counterpart in other plant species, also plays a positive role in cell death induction and defense response. Using bimolecular fluorescence complementation analysis, we determined that GmMKK4 might function upstream of GmMPK6 and GmMKK4 could interact with GmMPK6 independent of its phosphorylation status. Taken together, our results indicate that GmMPK6 functions as both repressor and activator in defense responses of soybean.
    Download Collect
  • Enhanced Production of Pinene by Using a Cell-Free System with Modular Cocatalysis

    Niu, Fu-Xing   Huang, Yuan-Bin   Shen, Yu-Ping   Ji, Liang-Nian   Liu, Jian-Zhong  

    Download Collect
  • Pore structure and fractal analysis of Ximeng lignite under microwave irradiation

    Liu, Jian-Zhong   Zhu, Jie-Feng   Cheng, Jun   Zhou, Jun-Hu   Cen, Ke-Fa  

    The pore structure and fractal analysis of Ximeng lignite (XL) under microwave irradiation were investigated. Effects of drying temperature, microwave irradiation time, and microwave power level were studied. The pore structures of XL were obtained by N-2 adsorption/desorption at 77 K. Two fractal dimensions, D-1 and D-2, at relative pressures of 0-0.5 and 0.5-1, respectively, were calculated with the fractal Frenkel-Halsey-Hill model. The specific surface area of the microwave-treated XL differently decreased, whereas its average pore diameter and total pore volume differently increased. However, the evolution mechanisms of pore structures during microwave drying were similar. These mechanisms included the collapse of pore structures caused by shrinkage forces that resulted from the removal of moisture, open and cross-linking of blind and closed pores, and thermal decomposition of organic macromolecular structures under a high temperature. The changes in D-1 were similar to those in average pore diameter development, whereas the changes in D-2 were consistent with those in specific surface area development. The reliability of the relationship between D-2 and mesopores was examined with some scanning electron microscope images and D-2 can reflect the volumetric roughness of mesopores. (C) 2015 Elsevier Ltd. All rights reserved.
    Download Collect
  • Loss of GSNOR1 Function Leads to Compromised Auxin Signaling and Polar Auxin Transport.

    Shi, Ya-Fei   Wang, Da-Li   Wang, Chao   Culler, Angela Hendrickson   Kreiser, Molly A   Suresh, Jayanti   Cohen, Jerry D   Pan, Jianwei   Baker, Barbara   Liu, Jian-Zhong  

    Cross talk between phytohormones, nitric oxide (NO), and auxin has been implicated in the control of plant growth and development. Two recent reports indicate that NO promoted auxin signaling but inhibited auxin transport probably through S-nitrosylation. However, genetic evidence for the effect of S-nitrosylation on auxin physiology has been lacking. In this study, we used a genetic approach to understand the broader role of S-nitrosylation in auxin physiology in Arabidopsis. We compared auxin signaling and transport in Col-0 and gsnor1-3, a loss-of-function GSNOR1 mutant defective in protein de-nitrosylation. Our results showed that auxin signaling was impaired in the gsnor1-3 mutant as revealed by significantly reduced DR5-GUS/DR5-GFP accumulation and compromised degradation of AXR3NT-GUS, a useful reporter in interrogating auxin-mediated degradation of Aux/IAA by auxin receptors. In addition, polar auxin transport was compromised in gsnor1-3, which was correlated with universally reduced levels of PIN or GFP-PIN proteins in the roots of the mutant in a manner independent of transcriptionand 26S proteasome degradation. Our results suggest that S-nitrosylation and GSNOR1-mediated de-nitrosylation contribute to auxin physiology, and impaired auxin signaling and compromised auxin transport are responsible for the auxin-related morphological phenotypes displayed by the gsnor1-3 mutant. Copyright =C2=A9 2015 The Author. Published by Elsevier Inc. All rights reserved.
    Download Collect
  • Gaining insight into soybean defense responses using functional genomics approaches: Figure 1

    Liu, Jian-Zhong   Graham, Michelle A.   Pedley, Kerry F.   Whitham, Steven A.  

    Download Collect
  • Production of L-ornithine from sucrose and molasses by recombinant Corynebacterium glutamicum

    Zhang, Yuan-Yuan   Bu, Yi-Fan   Liu, Jian-Zhong  

    Sucrose and molasses are attractive raw materials for industrial fermentation. Although Corynebacterium glutamicum shows sucrose-utilizing activity, sucrose or molasses is only a fraction of carbon source used in the fermentation medium in most works. An engineered C. glutamicum strain was constructed for producing L-ornithine with sucrose or molasses as a sole carbon source by transferring Mannheimia succiniciproducens beta-fructofuranosidase gene (sacC). The engineered strain, C. glutamicum Delta APE6937R42 (pEC-sacC), produced 22.0 g/L of L-ornithine with sucrose as the sole carbon source, which is on par with that obtained by the parent strain C. glutamicum Delta APE6937R42 with glucose as the sole carbon. The resulting strain C. glutamicum Delta APE6937R42 (pEC-sacC) produced 27.0 g/L of L-ornithine with molasses as the sole carbon source, which is higher than that obtained by the parent strain C. glutamicum Delta APE6937R42 with glucose as the sole carbon. This strategy can be applied for developing sucrose- or molasses-utilizing industrial strains.
    Download Collect
  • Metabolic Engineering of Escherichia coli for Producing Astaxanthin as the Predominant Carotenoid

    Lu, Qian   Bu, Yi-Fan   Liu, Jian-Zhong  

    Astaxanthin is a carotenoid of significant commercial value due to its superior antioxidant potential and wide applications in the aquaculture, food, cosmetic and pharmaceutical industries. A higher ratio of astaxanthin to the total carotenoids is required for efficient astaxanthin production. -Carotene ketolase and hydroxylase play important roles in astaxanthin production. We first compared the conversion efficiency to astaxanthin in several -carotene ketolases from Brevundimonas sp. SD212, Sphingomonas sp. DC18, Paracoccus sp. PC1, P. sp. N81106 and Chlamydomonas reinhardtii with the recombinant Escherichia coli cells that synthesize zeaxanthin due to the presence of the Pantoea ananatis crtEBIYZ. The B. sp. SD212 crtW and P. ananatis crtZ genes are the best combination for astaxanthin production. After balancing the activities of -carotene ketolase and hydroxylase, an E. coli ASTA-1 that carries neither a plasmid nor an antibiotic marker was constructed to produce astaxanthin as the predominant carotenoid (96.6%) with a specific content of 7.4 +/- 0.3 mg/g DCW without an addition of inducer.
    Download Collect
  • S-nitrosylation inhibits the kinase activity of tomato phosphoinositide-dependent kinase 1 (PDK1)

    Liu, Jian-Zhong   Duan, Jicheng   Ni, Min   Liu, Zhen   Qiu, Wen-Li   Whitham, Steven A.   Qian, Wei-Jun  

    Download Collect
  • Effects of temperature on fertilized eggs and larvae of tawny puffer Takifugu flavidus

    Zhang, Gen-Yu   Zhu, Ya-Zhu   Liu, Jian-Zhong   Zang, Wei-Ling  

    Tawny puffer Takifugu flavidus is a species found in China considered to have potential for aquaculture. Experiments were conducted to determine the optimal temperature for its incubation and larval culture. Fertilized eggs collected from cultured broodstocks that were induced to ovulate with a [D-Ala(6)-Pro(9)-Net]-luteinizing hormone-releasing hormone analogue were inseminated. The effect of temperature (19, 20, 23, 26 and 29 degrees C) on the hatch rate, incubation period, viability of 24 h post-hatch larvae and total mortality rate was assessed. The effect of temperature (20, 23, 26 and 29 degrees C) on the growth and survival of larvae from 3 to 19 days after hatching (dah) was also assessed. The results showed that the optimal temperature for successful development of fertilized eggs ranged from 23 to 26 degrees C, and the highest hatch rate, the optimal viability of 24 h post-hatch larvae and the lowest total mortality rate were all predicted using quadratic equations. The relationship between temperature and the incubation period of tawny puffer eggs was determined using the effective degree-day model. The temperature at developmental zero (t(0)) was 11.34 degrees C, and the sum of effective degree-days (k) was 52.356. The survival rate of tawny puffer larvae at 20 degrees C was significantly lower than among 23, 26 and 29 degrees C, whereas the survival rate was not significantly different from that at 23,26 and 29 degrees C. The larval growth rate increased rapidly as the temperature increased, showing a linear relationship in the range of temperatures investigated. The optimal temperature for larval culture ranged from 23 to 29 degrees C.
    Download Collect
  • 9,9-Dibenzyl-10-trimethylsilyl-9,10-dihydroanthracene

    Liu, Jian-Zhong   Dhar, Raj K.   Fronczek, Frank R.   Rabideau, Peter W.   Watkins, Steven F.  

    The title compound, C31H32Si or (C6H5CH2)(2)C14H9Si(CH3)(3), has a concave dihydroanthracene unit. The central ring adopts a half-chair conformation and the two benzene rings are tilted by 14.40 (7)degrees with respect to one another. The trimethylsilyl group is substituted in the axial position of the half-chair.
    Download Collect
  • A mathematical model for gluconic acid fermentation by Aspergillus niger

    Liu, Jian-Zhong   Weng, Li-Ping   Zhang, Qian-Ling   Xu, Hong   Ji, Liang-Nian  

    The fermentation kinetics of gluconic acid by Aspergillus niger were studied in a batch system. A simple model was proposed using the logistic equation for growth, the Luedeking–Piret equation for gluconic acid production and Luedeking–Piret-like equation for glucose consumption. The model appeared to provide a reasonable description for each parameter during the growth phase. The production of gluconic acid was growth-associated.
    Download Collect
1 2 3

Contact

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback