國立臺南大學專任教師基本資料
姓名吳慧珍
系所生物科技學系
職稱助理教授
校內分機796
EMAILhuichenwu@mail.nutn.edu.tw
辦公室C106
網址 
專長/研究領域植物病理、植物逆境生理、生物燃料
學位畢業學校國別主修學門修業期間
博士臺灣大學台灣植物科學研究所2005 / 2 至 2010 / 11
博士法國蒙彼利耶第二大學( University de Montpellier 2,UM2)法國\Biologie Intégrative des Plantes2007 / 11至 2010 / 11
著作名稱:Heat Shock Proteins in Signaling Pathways
年度:2019
類別:專書
摘要:A remarkable number of strategies has been developed by living organisms to mitigate conflict with environmental changes. The global environment rising with ambient temperature has a wide range of effects on plant growth, and therefore activation of various molecular defenses before the appearance of heat damage. Evidence revealed key components of stress that trigger enhanced tolerance, and some determinants for plant tolerance have been identified. The interplay between heat shock proteins (HSP) and redox proteins is supposed to be vital for the survival under extreme stress conditions. Any circumstance in which cellular redox homeostasis is disrupted can lead to the generation of reactive oxygen species (ROS) that are continuously generated in cells as an unavoidable consequence of aerobic life. Integrative network analysis of synthetic genetic interactions, protein-protein interactions, and functional annotations revealed many new functional processes linked to heat stress (HS) and oxidative stress (OS) tolerance, implicated upstream regulators activated by the either HS or OS, and revealed new connections between them. We present different models of acquired stress resistance to interpret the condition-specific involvement of genes. Considering the basic concepts and the recent advances, the following subsections provide an overview of calcium ion (Ca2+) and ROS interplay in abiotic signaling pathways; further we introduce several examples of chaperone and redox proteins that respond the change of cellular redox status under environmental circumstances. Thus, the involvement or contribution of redox proteins through the functional switching in conjunction with the HSP that prevent heat- and oxidative-induced protein aggregation in plants.
關鍵字:Calcium ion, Chaperone, Heat shock proteins, Heat stress, Oxidative stress, Reactive oxygen species, Redox proteins
著作名稱:2018 Environment and Photosynthesis: A Future Prospect
年度:2018
類別:專書
摘要:Diethyl phthalate (DEP), one of short chain and low molecular weight phthalic acid esters (PAEs), is widely used in industry as a plasticizer to increase the flexibility of polymer in many products. With a greater bioaccumulation factor than larger PAEs, such as di (2-ethylhexyl) phthalate (DEHP), DEP and the metabolites may interfere with animal growth and development by disrupting the endogenous hormone action and their receptors. DEP was classified as one of the priority organic pollutants by USEPA. DEP may cause oxidative stress, partially through accumulation of superoxide and/or hydrogen peroxide leading to membrane peroxidation, chlorophyll degradation, protein accumulation and turnover, and reduction in nitrogen assimilation. No available data suggest that any aquatic plant is a significant source of DEP in ecosystems. However, this was the only PAEs that was identified as one of the 15 potentially allelopathic compounds from root exudates of barnyard grass. In this chapter, we first review the toxic effects of DEP on plant growth and development. We also introduce our application of the JIP-test analysis to monitor the photosynthetic response to the DEP stress in greater duckweed, an aquatic plant model, and discuss the future prospective.
關鍵字:Diethyl phthalate, Spirodela polyrhiza, Chlorophyll a fluorescence, Photosystem II, Reactive oxygen species
著作名稱: The iron-sulfur protein NFU2 plays a predominant role in branched-chain amino acid synthesis in Arabidopsis roots.
年度:2019
類別:期刊論文
摘要:Numerous proteins require a metallic cofactor for their function. In plastids, the maturation of iron-sulfur (Fe-S) proteins necessitates a complex assembly machinery. We focused on Arabidopsis thaliana NFU1, NFU2 and NFU3, which participate in the late maturation steps. According to the strong photosynthesis defects observed in high chlorophyll fluorescence 101 (hcf101), nfu2 and nfu3 plants, we determined that NFU2 and NFU3, but not NFU1, act immediately upstream from HCF101 for the maturation of [Fe4S4]-containing photosystem I subunits. An additional function of NFU2 in the maturation of the [Fe2S2] cluster of a dihydroxyacid dehydratase was obvious from the accumulation of precursors of the branched-chain amino acid synthesis pathway in nfu2 roots and the rescue of the primary root growth defect by supplying branched-chain amino acids. The absence of NFU3 in roots precluded any compensation. Overall, unlike their eukaryotic and prokaryotic counterparts, which are specific of [Fe4S4] proteins, NFU2 and NFU3 contribute to the maturation of both [Fe2S2] and [Fe4S4] proteins either as a relay in conjunction with other proteins such as HCF101 or by directly delivering Fe-S clusters to client proteins. Considering the low number of Fe-S cluster transfer proteins relative to final acceptors, additional targets probably await identification.
關鍵字:Arabidopsis thaliana, branched-chain amino acids, chloroplast, development, iron-sulfur protein, photosynthesis
著作名稱:Evaluation of Virulence and Pathogenicity of Alternaria patula on French Marigold (Tagetes patula Linn)
年度:2018
類別:期刊論文
摘要:Alternaria patula, the cause of French marigold leaf black spot and flower blight, was first isolated from seeds of French marigold cv. Queen Sophia. It is described as a new species of Alternaria and has a considerable morphological variation with a preferential pathogenicity to Asteraceae, Solanaceae and Cucurbitaceae plants. Alternaria patula produces an array of pectin depolymerases that can break 1,4-a-glycosidic bonds either by hydrolysis of polygalacturonases (PG, E.C. 3.2.1.15) or via trans-elimination of pectate lyases (PL, E.C. 4.2.2.2) and pectin lyases (PNL, E.C.4.2.2.10). This study is the first to emphasize the variability and significance to pathogenesis of the pectinolytic enzymes of A. patula that target various pectic polymers structures during host tissue invasion. Alternaria patula also produced zinniol derivatives as non-host-specific toxins (nHSTs), albeit without phytotoxic symptoms in French marigold. The management of Alternaria blight caused by A. patula via the application of pyrifenox and antagonistic Bacillus amyloliquefaciens effectively reduced disease severity, without adverse effects on French marigold in both in vitro and in vivo bioassays.
關鍵字:Alternaria patula, Bacillus amyloliquefaciens, pectate lyases, pectin lyases, pyrifenox, zinniol
著作名稱:Pectin Methylesterases: Cell Wall Remodeling Proteins Are Required for Plant Response to Heat Stress
年度:2018
類別:期刊論文
摘要:Heat stress (HS) is expected to be of increasing worldwide concern in the near future, especially with regard to crop yield and quality as a consequence of rising or varying temperatures as a result of global climate change. HS response (HSR) is a highly conserved mechanism among different organisms but shows remarkable complexity and unique features in plants. The transcriptional regulation of HSR is controlled by HS transcription factors (HSFs) which allow the activation of HS-responsive genes, among which HS proteins (HSPs) are best characterized. Cell wall remodeling constitutes an important component of plant responses to HS to maintain overall function and growth; however, little is known about the connection between cell wall remodeling and HSR. Pectin controls cell wall porosity and has been shown to exhibit structural variation during plant growth and in response to HS. Pectin methylesterases (PMEs) are present in multigene families and encode isoforms with different action patterns by removal of methyl esters to influencing the properties of cell wall. We aimed to elucidate how plant cell walls respond to certain environmental cues through cell wall-modifying proteins in connection with modifications in cell wall machinery. An overview of recent findings shed light on PMEs contribute to a change in cell-wall composition/structure. The fine-scale modulation of apoplastic calcium ions (Ca2+) content could be mediated by PMEs in response to abiotic stress for both the assembly and disassembly of the pectic network. In particular, this modulation is prevalent in guard cell walls for regulating cell wall plasticity as well as stromal aperture size, which comprise critical determinants of plant adaptation to HS. These insights provide a foundation for further research to reveal details of the cell wall machinery and stress-responsive factors to provide targets and strategies to facilitate plant adaptation.
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著作名稱: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
著作名稱: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
著作名稱: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
著作名稱: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.
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著作名稱: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.
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著作名稱: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
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
著作名稱: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.
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著作名稱: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
著作名稱: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
著作名稱:Transcriptome Analysis of Arabidopsis PDAT1 Acyltransferase Reveals Key Candidate Genes-Mediated Triacylglycerol Biosynthesis
年度:2017
類別:研討會
摘要:Plant oils, in the form of triacylglycerols (TAGs), are one of interesting, and sustainable alternatives that are potential substitute for petroleum in many industrial applications. In Arabidopsis thaliana, phospholipid: diacylglycerol acyltransferase 1 (PDAT1), is one of key enzyme involved in TAG synthesis. By multiple sequence alignment and phylogenetic analysis, we found that of the Arabidopsis PDAT1, is more closely related to Camelina sativa, Eutrema salsugineum, Brassica rapa, and Citrus sinensis, sharing 99 % amino acid sequences identity. The promoter region of PDAT1 contains a large number of putative cis-elements, to date, not functionally defined and need for further characterized. We are looking for the promoter region of PDAT1 in bioinformatics areas to identify the elements involved in the regulation of PDAT1 expression. We Isolated and characterized the new candidate regulators of PDAT1 for TAG synthesis to enhance seed oil contents. We are expected that PDAT1 and its regulators may as a new strategy to enhance oil accumulation in non-food crops for biofuel production.
關鍵字:Arabidopsis thaliana, Candidate regulators, PDAT1, Triacylglycerol
著作名稱:Characterization of key Regulators for Arabidopsis DGAT1 Acyltransferase Regulation Potentially Involved in Triacylglycerol Biosynthesis
年度:2017
類別:研討會
摘要:Plant oils are the most abundant energy storage compounds in the form of triacylglycerols (TAGs), and have become one of the most widely used as feedstocks for biodiesel. A barrier to increasing oil yields in seed crops has been the lack of knowledge concerning the regulation of genes that control TAG synthesis in oilseeds. Acyl-CoA: diacylglycerol acyltransferase 1 (DGAT1), is a key enzyme involved in the final step of TAG synthesis in Arabidopsis thaliana. By multiple sequence alignment and phylogenetic analysis, we found that of DGAT1 has high relationship with Camelina sativa which has a potential for biofuel feedstocks, sharing 92% amino acid sequences identity. The promoter region of DGAT1 contains a large number of putative cis-elements, to date, not functionally defined and need for further characterized. We isolated and characterized the new candidate regulators of DGAT1 for TAG synthesis to enhance seed oil contents. We are expected that DGAT1 and its regulators may as a new strategy to enhance oil accumulation in non-food crops for biofuel production.
關鍵字:Acyl-CoA: diacylglycerol acyltransferase 1, Arabidopsis thaliana, Biofuel, Candidate regulators, Triacylglycerols
著作名稱:Functional Characterization of Arabidopsis KASI Redirected to Medium-Chain Fatty Acids in Transgenic Oilseed Plants
年度:2017
類別:研討會
摘要:In seeds, lipids accumulate as triacylglycerols (TAGs) which contain medium-chain fatty acids (MCFAs) whose fatty acids having an aliphatic tail of 6–14 carbon atoms are of outstanding interest for the use as biofuel. In Arabidopsis thaliana, β-ketoacyl-acyl carrier protein synthase I (KASI, At5g46290), which is indispensable for fatty acid chain elongation from C4 to C16, but the KASI regulatory mechanism of MCFAs synthesis remains unknown. By multiple sequence alignment and phylogenetic analysis, Arabidopsis KASI shares 83 % amino acid sequences identity with KASI in Sesame (Sesamum indicum L.) which would enable production of MCFA oil. KASI promoter contains a large number of putative cis-elements, to date, not functionally defined and need for further characterized. Thus, we identify and characterize novel regulators of seed oil synthesis, and assess their ability to determine chain lengths of the fatty acid in TAGs. We are expected to develop new lines with ‘Medium’ chain fatty acid compositions for plant oil production.
關鍵字:Arabidopsis thaliana, Medium chain fatty acid, β-ketoacyl-acyl carrier protein synthase I
著作名稱:Redirecting Carbon to Triacylglycerol Synthesis in Developing Oilseeds
年度:2016
類別:研討會
摘要:By isolating new genes for improving the yield of oilseed crops we address the increasing demand for vegetable oils for nutritional, industrial and biodiesel use. A major barrier to increasing oil yields has been the lack of knowledge concerning the regulation of assimilate partitioning among seed components. Our goal is to identify novel factors that control the synthesis of triacylglycerol and to assess the extent to which carbon can be re-directed from structural (carbohydrate) and reserve (protein) components to enhance oil yield. FUSCA3 is prominent in controlling lipid synthesis such that a defect in this gene (fus3) leads to a severe reduction in seed oil. We mutagenised a population of fus3 seeds that contained selection markers to identify plants with near-normal seed lipid and protein contents in order to isolate the genes (SOF1 and SOF2) responsible for the suppression of low oil in fus3. Genome re-sequencing of candidate lines identified genes encoding sugar and redox sensors as putative fus3 suppressors which we are currently validating. In a complementary screen, four distinct DNA binding proteins were isolated as putative regulators of genes encoding acyltransferase enzymes essential for oil synthesis and were transformed into Camelina sativa to assess their effect on seed oil accumulation. The candidate regulators isolated in Arabidopsis allow us to refine models of the control of carbon partitioning in seeds and also constitute novel genes to engineer carbon partitioning to oil. We anticipate that foreground obtained within SYNERGY will also impact on the potential for the production of high value products in seeds and energy densification of biomass. It is axiomatic that an understanding of carbon partitioning would also permit enhancement of protein reserves or starch in seeds of diverse species.
關鍵字:Camelina sativa, FUSCA3, SYNERGY, Triacylglycerol
著作名稱: Nfu2 and Nfu3 act with HCF101 to transfer 4Fe- 4S clusters to PSI
年度:2016
類別:研討會
摘要:Nfu proteins are hypothesized to be scaffold proteins in vivo for iron-sulphur cluster biogenesis actors downstream of the SUFBCD carrier complex. Three Nfu proteins (Nfu1 to 3) are located into the chloroplast. We explored the scaffold function of the three chloroplastic Nfu proteins by combining interactomic approaches (yeast two hybrid) and phenotypical characterization of loss-of-function mutants in the corresponding genes. Both nfu2 and nfu3 mutants exhibited a dwarf phenotype due to photosynthetic limitation. Photosynthesis study of these mutants revealed an altered photosystem I (PSI) activity together with a decrease in PSI amount. Molecular and biochemical analysis showed that these two proteins, acting together with the P loop ATPase HCF101, are essential to bring 4Fe- 4S clusters to PSI. Beyond this photosystem, more than 40 chloroplastic proteins contain Fe-S clusters. The involvement of Nfu2 and Nfu3 in the biogenesis of other plastidial apo-proteins is unclear. Position of Nfu proteins with respect to other components of the chloroplastic iron-sulphur machinery (SUF, NFS) will be presented, and hypotheses regarding the scaffold proteins involved in other cluster biogenesis than PSI will be discussed.
關鍵字:Fe-S cluster, NFU, Scaffold proteins, Photosystem I, Arabidopsis
著作名稱:Insight into the Developmental and Transcriptional Regulation of Triacylglycerol Synthesis in Oilseeds
年度:2015
類別:研討會
摘要:One approach to enhance vegetable oil yield would be to alter the partitioning of carbon in seeds to favour the synthesis of triacylglycerol. Such an approach requires knowledge of the genetic determinants governing seed development and carbon partitioning in seeds. Despite the importance of ABSCISIC ACID INSENSITIVE3 (ABI3), FUSCA3 (FUS3), and LEAFY COTYLEDON2 (LEC2), collectively the AFL factors, in the control of seed development and maturation processes, the extent and specificity to which these master regulators exert control over reserve accumulation is unclear. Furthermore, the mechanism of regulation of genes encoding triacylglycerol assembly and storage remains obscure. We have shown that AFL factors exert spatial and quantitative control over fatty acid modification, oil and protein accumulation but not starch, acting in a partially redundant manner. Among the AFL, FUS3 is prominent in the level of control exerted over fatty acid desaturation and triacylglycerol accumulation. By analysing the ability of an individual ectopically expressed AFL to genetically suppress afl mutations we have shown that the conserved B3 DNA binding domain is necessary and sufficient for the synthesis and accumulation of triacylglycerol and for the initiation, but not maintenance of seed storage protein synthesis nor for the acquisition of dormancy and desiccation tolerance. Thus the manipulation of AFL expression in afl mutants permits the uncoupling of mid and late maturation programmes to allow the identification of genes specific to each developmental phase. In rapeseed we have shown that FUS3 binds directly to the promoter of Bn-FAE1 and a FAE1 allele co-localised with a QTL for oil yield and that over expression of Bn-FUS3 enhances seed oil content.
關鍵字:AFL factors, triacylglycerol, QTL
著作名稱: Thiol- based Redox Regulation in Plant Tolerance to Abiotic Stress.
年度:2016
類別:研討會
摘要:Plants imperatively have to cope with many environmental imbalances (climate changes) and fine adjustment of the cellular redox status by detoxified excessive production of reactive oxygen species (ROS), avoiding progressive oxidative damage and cell death. Indeed, plants possess a large number of defensive genes coding for antioxidant proteins, including thioredoxins (Trxs) and glutaredoxins (Grxs) protein families responsible for dithiol/disulfide exchange reactions. In plants, Grxs can be classified into four classes. Some Grx members of class II (monothiol Grxs) with a strictly conserved CGFS active site are able to bind and to transfer their iron-sulfur (Fe-S) cluster. In addition, in yeast and human, Grxs were shown to form Fe-S cluster-bridged heterodimers with BolA proteins. Whereas the physical interaction between CGFS Grx and BolA from several model organisms seems clear, the function of such complexes in plant is totally unknown. By combining biochemical, structural and functional approaches, we confirmed that the interactions between Grxs and BolA proteins are conserved in plants. The functional interpretation might be that the DNA-binding activity or any other function of BolA is redox-regulated, in particular in response to oxidative conditions. For clarity, the hypothesis that BolA converts monothiol Grxs from carrier proteins to Fe or Fe–S sensors by forming Fe–S cluster-bridged heterodimers instead of Fe–S cluster-bridged homodimers has not been illustrated.
關鍵字:BolA, Environmental imbalances, Iron-sulfur (Fe-S) cluster, Monothiol glutaredoxins, redox regulation