國立臺南大學教師基本資料

基本資料
姓名 吳慧珍
系所 生物科技學系
職稱 助理教授
校內分機 796
傳真 06-2606153
辦公室/研究室 C106
E-mail huichenwu@mail.nutn.edu.tw
網址
專長/研究領域 微生物學、植物逆境生理、生物燃料
 

畢業學校國別主修學門學位修業期間
臺灣大學台灣植物科學研究所博士2005 / 2 至 2010 / 11
法國蒙彼利耶第二大學( University de Montpellier 2,UM2)法國\Biologie Intégrative des Plantes博士2007 / 11至 2010 / 11

服務機關部門 / 系所職稱服務期間

著作
名稱Pectin methylesterase activity is required for thermotolerance in soybean seedlings
年度2010
類別期刊論文
摘要Synthesis of heat shock proteins (HSPs) in response to heat shock (HS) is essential for thermotolerance. The effect of a Ca2+ chelator, EGTA, was investigated before a lethal HS treatment in soybean (Glycine max) seedlings with acquired thermotolerance induced by preheating. Such seedlings became non-thermotolerant with EGTA treatment. The addition of Ca2+, Sr2+ or Ba2+ to the EGTA-treated samples rescued the seedlings from death by preventing the increased cellular leakage of electrolytes, amino acids, and sugars caused by EGTA. It was confirmed that EGTA did not affect HSP accumulation and physiological functions but interfered with the recovery of HS-released Ca2+ concentration which was required for thermotolerance. Pectin methylesterase (PME, EC 3.1.1.11), a cell wall remodelling enzyme, was activated in response to HS, and its elevated activity caused an increased level of demethylesterified pectin which was related to the recovery of the HS-released Ca2+ concentration. Thus, the recovery of HS-released Ca2+ in Ca2+-pectate reconstitution through PME activity is required for cell wall remodelling during HS in soybean which, in turn, retains plasma membrane integrity and co-ordinates with HSPs to confer thermotolerance.
關鍵字 Ca2+, heat shock, pectin, pectin methylesterase, thermotolerance
名稱Direct interaction between the rice yellow mottle virus VPg and the central domain of the rice eIF(iso)4G1 factor correlates with rice susceptibility and RYMV virulence.
年度2010
類別期刊論文
摘要The adaptation of Rice yellow mottle virus (RYMV) to recessive resistance mediated by the rymv1-2 allele has been reported as a model to study the emergence and evolution of virulent variants. The resistance and virulence factors have been identified as eukaryotic translation initiation factor eIF(iso)4G1 and viral genome-linked protein (VPg), respectively, but the molecular mechanisms involved in their interaction are still unknown. In this study, we demonstrated a direct interaction between RYMV VPg and the central domain of rice eIF(iso)4G1 both in vitro, using recombinant proteins, and in vivo, using a yeast two-hybrid assay. Insertion of the E309K mutation in eIF(iso)4G1, conferring resistance in planta, strongly diminished the interaction with avirulent VPg. The efficiency of the major virulence mutations at restoring the interaction with the resistance protein was assessed. Our results explain the prevalence of virulence mutations fixed during experimental evolution studies and are consistent with the respective viral RNA accumulation levels of avirulent and virulent isolates. Our results also explain the origin of the residual multiplication of wild-type isolates in rymv1-2-resistant plants and the role of genetic context in the poor adaptability of the S2/S3 strain. Finally, the strategies of RYMV and members of family Potyviridae to overcome recessive resistance were compared.
關鍵字
名稱Heat shock-triggered Ca2+ mobilization accompanied by pectin methylesterase activity and cytosolic Ca2+ oscillation are crucial for plant thermotolerance.
年度2010
類別期刊論文
摘要Apoplastic Ca2+ concentration controls membrane permeability, cell wall stabilization and cell integrity; however, little is known about its role in thermotolerance in plants. Here, we report that the acquired thermotolerance of etiolated rice seedlings (Oryza sativa) was abolished by an exogenously supplied Ca2+ chelator, EGTA, related to increased cellular content leakage during heat shock (HS) treatment. Thermotolerance was restored by the addition of Ca2+ during EGTA incubation. Pectin methylesterase (EC 3.1.1.11), a cell-wall remodeling enzyme, was activated in response to HS and its elevated activity was related to the recovery of the HS-released Ca2+ concentration. EGTA interfered with the capability of HS to increase oscillation of [Ca2+]cyt content. We assume that heat-activated PME activity is involved in cell-wall localized Ca2+. The removal of apoplastic Ca2+ might participate in HS signaling to induce HS protein expression and cell-wall remodeling to retain plasma membrane integrity, prevent cellular content leakage and confer thermoprotection.
關鍵字Ca2+, cell wall, EGTA, HSP, HSR, pectin methylesterase, thermotolerance
名稱Oscillation regulation of Ca2+/calmodulin and heat-stress related genes in response to heat stress in rice (Oryza sativa L.).
年度2012
類別期刊論文
摘要The Ca2+/calmodulin (CaM) signaling pathway mediates the heat stress (HS) response and acquisition of thermotolerance in plants. We showed that the rice CaM1-1 isoform can interpret a Ca2+ signature difference in amplitude, frequency, and temporal–spatial properties in regulating transcription of nucleoplasmic small heat-shock protein gene (sHSPC/N) during HS. Ca2+ and A23187 treatments under HS generated an intense and sustained increase in [Ca2+]cyt and accelerated the expression of CaM1-1 and sHSPC/N genes, which suggests that HS-induced apoplastic Ca2+ influx was responsible for the [Ca2+]cyt transient and downstream HS signaling. Here, we discuss an emerging paradigm in the oscillation regulation of CaM1-1 expression during HS and highlight the areas that need further investigation.
關鍵字Ca2+, calmodulin, heat shock signaling, temporal–spatial regulation, thermotolerance
名稱Heat shock-induced biphasic Ca2+ signature and CaM1-1 nuclear localization mediates downstream signaling in acquisition of thermotolerance in rice (Oryza sativa L.).
年度2012
類別期刊論文
摘要We investigated heat shock (HS)-triggered Ca(2+) signalling transduced by a Ca(2+) sensor, calmodulin (CaM), linked to early transcriptome changes of HS-responsive genes in rice. We observed a biphasic [Ca(2+) ](cyt) signature in root cells that was distinct from that in epicotyl and leaf cells, which showed a monophasic response after HS. Treatment with Ca(2+) and A23187 generated an intense and sustained increase in [Ca(2+) ](cyt) in response to HS. Conversely, treatment with Ca(2+) chelator, L-type Ca(2+) channel blocker and CaM antagonist, but not intracellular Ca(2+) release inhibitor, strongly inhibited the increased [Ca(2+) ](cyt) . HS combined with Ca(2+) and A23187 accelerated the expression of OsCaM1-1 and sHSPC/N genes, which suggests that the HS-induced apoplastic Ca(2+) influx is responsible for the [Ca(2+) ](cyt) response and downstream HS signalling. In addition, the biphasic response of OsCaM1-1 in the nucleus followed the Ca(2+) signature, which may provide the information necessary to direct HS-related gene expression. Overexpression of OsCaM1-1 induced the expression of Ca(2+) /HS-related AtCBK3, AtPP7, AtHSF and AtHSP at a non-inducing temperature and enhanced intrinsic thermotolerance in transgenic Arabidopsis. Therefore, HS-triggered rapid increases in [Ca(2+) ](cyt) , together with OsCaM1-1 expression and its nuclear localization, are important in mediating downstream HS-related gene expression for the acquisition of thermotolerance in rice.
關鍵字
名稱Arabidopsis thaliana Nfu2 accommodates [2Fe-2S] or [4Fe-4S] clusters and is competent for in vitro maturation of chloroplast [2Fe-2S] and [4Fe-4S] cluster-
年度2013
類別期刊論文
摘要Nfu-type proteins are essential in the biogenesis of iron–sulfur (Fe-S) clusters in numerous organisms. A number of phenotypes including low levels of Fe-S cluster incorporation are associated with the deletion of the gene encoding a chloroplast-specific Nfu-type protein, Nfu2 from Arabidopsis thaliana (AtNfu2). Here, we report that recombinant AtNfu2 is able to assemble both [2Fe-2S] and [4Fe-4S] clusters. Analytical data and gel filtration studies support cluster/protein stoichiometries of one [2Fe-2S] cluster/homotetramer and one [4Fe-4S] cluster/homodimer. The combination of UV–visible absorption and circular dichroism and resonance Raman and Mössbauer spectroscopies has been employed to investigate the nature, properties, and transfer of the clusters assembled on Nfu2. The results are consistent with subunit-bridging [2Fe-2S]2+ and [4Fe-4S]2+ clusters coordinated by the cysteines in the conserved CXXC motif. The results also provided insight into the specificity of Nfu2 for the maturation of chloroplastic Fe-S proteins via intact, rapid, and quantitative cluster transfer. [2Fe-2S] cluster-bound Nfu2 is shown to be an effective [2Fe-2S]2+ cluster donor for glutaredoxin S16 but not glutaredoxin S14. Moreover, [4Fe-4S] cluster-bound Nfu2 is shown to be a very rapid and efficient [4Fe-4S]2+ cluster donor for adenosine 5′-phosphosulfate reductase (APR1), and yeast two-hybrid studies indicate that APR1 forms a complex with Nfu2 but not with Nfu1 and Nfu3, the two other chloroplastic Nfu proteins. This cluster transfer is likely to be physiologically relevant and is particularly significant for plant metabolism as APR1 catalyzes the second step in reductive sulfur assimilation, which ultimately results in the biosynthesis of cysteine, methionine, glutathione, and Fe-S clusters.
關鍵字
名稱Monothiol Glutaredoxin–BolA Interactions: Redox Control of Arabidopsis thaliana BolA2 and SufE1
年度2014
類別期刊論文
摘要A functional relationship between monothiol glutaredoxins and BolAs has been unraveled by genomic analyses and in several high-throughput studies. Phylogenetic analyses coupled to transient expression of green fluorescent protein (GFP) fusions indicated that, in addition to the sulfurtransferase SufE1, which contains a C-terminal BolA domain, three BolA isoforms exist in Arabidopsis thaliana, BolA1 being plastidial, BolA2 nucleo-cytoplasmic, and BolA4 dual-targeted to mitochondria and plastids. Binary yeast two-hybrid experiments demonstrated that all BolAs and SufE1, via its BolA domain, can interact with all monothiol glutaredoxins. Most interactions between protein couples of the same subcellular compartment have been confirmed by bimolecular fluorescence complementation. In vitro experiments indicated that monothiol glutaredoxins could regulate the redox state of BolA2 and SufE1, both proteins possessing a single conserved reactive cysteine. Indeed, a glutathionylated form of SufE1 lost its capacity to activate the cysteine desulfurase, Nfs2, but it is reactivated by plastidial glutaredoxins. Besides, a monomeric glutathionylated form and a dimeric disulfide-bridged form of BolA2 can be preferentially reduced by the nucleo-cytoplasmic GrxS17. These results indicate that the glutaredoxin–BolA interaction occurs in several subcellular compartments and suggest that a redox regulation mechanism, disconnected from their capacity to form iron–sulfur cluster-bridged heterodimers, may be physiologically relevant for BolA2 and SufE1.
關鍵字BolA,Glutaredoxin,Interaction,Redox control
名稱Pectin Methylesterase is Required for Guard Cell Function in Response to Heat
年度2017
類別期刊論文
摘要Pectin is an important cell wall polysaccharide required for cellular adhesion, extension, and plant growth. The pectic methylesterification status of guard cell walls influences the movement of stomata in response to different stimuli. Pectin methylesterase (PME) has a profound effect on cell wall modification, especially on the degree of pectic methylesterification during heat response. The Arabidopsis thaliana PME34 gene is highly expressed in guard cells and in response to the phytohormone abscisic acid. The genetic data highlighted the significant role of PME34 in heat tolerance through the regulation of stomatal movement. Thus, the opening and closure of stomata is mediated by changes in response to a given stimulus, could require a specific cell wall modifying enzyme to function properly.
關鍵字Guard cell; heat stress; pectin; pectin methylesterase; thermotolerance; transpiration
名稱Using Silicon Polymer Impression Technique and Scanning Electron Microscopy to Measure Stomatal Aperture, Morphology, and Density.
年度2017
類別期刊論文
摘要The number of stomata on leaves can be affected by intrinsic development programming and various environmental factors, in addition the control of stomatal apertures is extremely important for the plant stress response. In response to elevated temperatures, transpiration occurs through the stomatal apertures, allowing the leaf to cool through water evaporation. As such, monitoring of stomata behavior to elevated temperatures remains as an important area of research. The protocol allows analysis of stomatal aperture, morphology, and density through a non-destructive imprint of Arabidopsis thaliana leaf surface. Stomatal counts were performed and observed under a scanning electron microscope.
關鍵字Arabidopsis thaliana, Heat stress, Non-destructive imprint, Stomata, Scanning electron microscope
名稱PECTIN METHYLESTERASE34 Contributes to Heat Tolerance through Its Role in Promoting Stomatal Movement.
年度2017
類別期刊論文
摘要Pectin, a major component of the primary cell wall, is synthesized in the Golgi apparatus and exported to the cell wall in a highly methylesterified form, then is partially demethylesterified by pectin methylesterases (PMEs; EC 3.1.1.11). PME activity on the status of pectin methylesterification profoundly affects the properties of pectin and, thereby, is critical for plant development and the plant defense response, although the roles of PMEs under heat stress (HS) are poorly understood. Functional genome annotation predicts that at least 66 potential PME genes are contained in Arabidopsis (Arabidopsis thaliana). Thermotolerance assays of PME gene T-DNA insertion lines revealed two null mutant alleles of PME34 (At3g49220) that both consistently showed reduced thermotolerance. Nevertheless, their impairment was independently associated with the expression of HS-responsive genes. It was also observed that PME34 transcription was induced by abscisic acid and highly expressed in guard cells. We showed that the PME34 mutation has a defect in the control of stomatal movement and greatly altered PME and polygalacturonase (EC 3.2.1.15) activity, resulting in a heat-sensitive phenotype. PME34 has a role in the regulation of transpiration through the control of the stomatal aperture due to its cell wall-modifying enzyme activity during the HS response. Hence, PME34 is required for regulating guard cell wall flexibility to mediate the heat response in Arabidopsis.
關鍵字Heat, Pectin methylesterase 34, Stomata, Thermotolerance