Characterization and expression analysis of TNF-related apoptosis inducing ligand (TRAIL) in grass carp Ctenopharyngodon idella

TRAIL (Apo2 ligand) described as a type II transmembrame protein belonging to the TNF superfamily can induce apoptotic cell death in a variety of cell types. In the present study, a putative cDNA sequence encoding the 299 amino acids of TRAIL (GC-TRAIL) and its genomic organization were identified in grass carp Ctenopharyngodon idella. The predicted GC-TRAIL sequence showed 44 and 41% identities to chicken and human TRAILs, respectively. In a domain search, a tumor necrosis factor homology domain (THD) was identified in the C-terminal portion of TRAILs. The GC-TRAIL gene consists of five exons, with four intervening introns, spaced over approximately 4 kb of genomic sequence. Analysis of GC-TRAlL promoter region revealed the presence of a number of putative transcription factor binding sites, such as Sp1, NF-kappaB, AP-1, GATA, NFAT, HNF, STAT, P53 and IRFI sequences which are important for the expression of other TNF family members. Phylogenetic analysis placed GC-TRAIL and the putative zebrafish (Danio rerio) TRAIL obtained from searching the zebrafish database into one separate cluster near mammalian TRAIL genes, but apart from the reported zebrafish TRAIL-like protein, indicating that the GC-TRAIL is an authentic fish TRAIL. Expression analysis revealed that GC-TRAIL is expressed in many tissues, such as in gills, liver, trunk kidney, head kidney, intestine and spleen. (c) 2005 Elsevier B.V. All rights reserved.

Characterization of development-related genes for the cestode Bothriocephalus acheilognathi

Differential gene expression of mature and immature Bothriocephalus acheilognathi cestodes was analyzed using the suppression subtractive hybridization technique. Five mature-associated cDNAs were isolated and characterized. Virtual Northern blot and RT-PCR analyses confirmed that four of the five genes were up-regulated in mature parasites. The sequence analysis revealed that one gene encoded the structural protein chorion precursor, and that three encoded functional proteins homologous to yolk ferritin, sodium/hydrogen exchanger and muscin-like protein. Another gene appeared to be specific to B. acheilognathi, encoding a putative metal-bound protein. Although results obtained in the present study are preliminary, the information about the five genes may provide clues for further investigation on the decline in parasite numbers during the maturation of B. acheilognathi.

固斑蝰蛇毒C-型凝集素样蛋白Dabocetin及L-氨基酸氧化酶DRS-LAO的研究

本论文研究了从圆斑蛙蛇泰国亚种（Daboia russellii siamensis）蛇毒中纯化的C一型凝集素样蛋白Dabocetin和L一氨基酸氧化酶DRS一AO的理化性质、生物学活性和分子克隆。Dabocetin是分子量约为28扔。的异二聚体蛋白，它由分子量约为15.0kDa和14．5kDa的两个同源亚基以和p共价结合形成。N－末端氨基酸序列比较显示，Dabocetin与目前已知的蛇毒c一型凝集素样蛋白有很高的同源性。即使在终浓度达50．0。叫而时，Dabocetin也不能直接诱导血小板聚集。此外，在终浓度为40.00μg/ml时，Dabocetin几乎不能抑制由AdP，TMVA和stejnulxin诱导的血小板聚集。但是，Dabocetin呈剂量依赖地抑制瑞斯托霉素诱导的血小板凝集，其半数抑制率ICS。值为10.80ug/ml。流式细胞仪分析表明，Dabocetin显著抑制单克隆抗体522与GPIba的结合，提示Dabocetin很可能是一个GPIb结合蛋白。从圆斑蛙蛇的毒腺中克隆到了7个编码不同蛇毒C一型凝集素样蛋白亚基的七DNA（命名为DRs一1至DRs一7）。其中，DRsLS编码Dabocetin的a亚基，DRS一6编码Dabocetin的p亚基。DRs一1和DRS一2很可能是圆斑蛙蛇毒腺中表达的X因子激活剂的两条轻链LCZ和LCI的山NA。DRS一3，DRS毛4和DRSL7可能是圆斑蛙蛇毒腺中表达的C一型凝集素样蛋白p亚基的。NA。DRsLAO是一个新的L一氨基酸氧化酶，比活力为1．98U加噶。十二烷基磺酸钠一聚丙烯酞氨凝胶电泳（SDs-PAGE）分析显示，该酶在还原和非还原条件下均呈现一条蛋白带，表观分子量约为58kDa。N-末端氨基酸序列比较显示，DRS一AO与目前已知的蛇毒L一氨基酸氧化酶有很高的同源性。该酶的最适底物为L一亮氨酸，最适pH为8．8。DRs一Ao呈剂量依赖地抑制扔P和仆IvA诱导的血小板聚集，其半数抑制率ICS。值分别为32.8μg/ml和32.3μg/ml。DRS-LAO对金黄色葡萄球菌（灯Cc25923）和耐甲氧西林金黄色葡萄球菌有较强的抗菌作用。DRs一AO对金黄色葡萄球菌必Tcc25923）的最低抑菌浓度卿C）和最低杀菌浓度耐甲氧西林金黄色葡萄球菌的孤CS。和呱Cg。值分别为18．。林留时和36.0μg/ml；DRSLAo对耐甲氧西林金黄色葡萄球菌的MBC50和MBCg。值分别为36.0μg/ml和72.0μg/ml。通过对DRS一AO的分子克隆，得到了编码DRS-AO的部分cDNA序列。

烙铁头蛇毒C-型凝集素样蛋白的生物活性及其作用机制研究

蛇毒C一型凝集素样蛋白一般是由两个相似亚基组成的异构二聚体或由多个异构二聚体组成的多聚体。烙铁头蛇毒血小板活化素TMVA是一个高分子量的C一型凝集素样蛋白。本文研究了烙铁头蛇毒C一型凝聚素样蛋白的生物活性及其作用机制。同时还从烙铁头蛇毒中分离到一个抗凝蛋白（mucroqucetin）。TMVA呈量效关系地诱导P好和洗涤血小板聚集，提示其活化血小板并不调节v从下或不依赖于vWF。抗人血小板糖蛋白（GP）Ib单克隆抗体HIPI呈剂量依赖性特异性抑制TMVA诱导的血小板聚集。抗人GPllb单克隆抗体PZ也抑制血小板聚集。单克隆抗体和流式细胞术分析显示，FITC一TMVA特异性地、剂量依赖性地结合到福尔马林固定的人血小板上，在FIIC-TMVA4O砚浓度时达到饱和性结合状态，这种结合被HIPI特异性地抑制，并呈剂量依赖性。TMVA不结合血小板GPIX、GPllb、GPllla、GPIa、GPlla和GPIV。Mocarhagin仅能部分阻断TMVA诱导的血小板聚集，然而TMVA却能诱导mocarhagin阻断的血小板聚集。以上结果显示TMVA在GPIbQ上的主要受体位于富含亮氨酸第二次重复区氨基酸残基59一81，除此之外，TMVA可能还有其他结合位点。小鼠体内首次给予TMVA后，在短时间内（15min-30min）引起循环血小板数及网织血小板百分率暂时性减低、血小板膜表面P-seleetin的表达暂时性增加，但循环血液中血小板一白细胞复合物未增加；抗鼠血小板单克隆抗体P一selectin、GPllb、GPlll。免疫组化染色显示脾和肺的组织巨噬细胞呈阴性反应，提示TMVA导致循环血小板减少不是巨噬细胞系统对血小板的清除所致。可能是由于TMVA．通过GPIb活化血小板后使P-selectin暴露于胞浆膜表面，这些脱颗粒的血小板在补体的参与下自身溶破，而导致快速的暂时性血小板减少。给予TMVA．后组织病理学显示，肝、脾、肺、肾、胰、大肠及小肠血管未血栓形成；TMVA不影响内源性和外源性凝血系统；TMVA呈剂量依赖性延长小鼠的出血时间，但在TMvA25p眺g时小鼠的出血时间未延长、仍小于5分钟，是一个安全的剂量。以上结果充分证明TMVA具有体内抗血栓作用，血小板自身溶破导致血小板减少在体内抗血栓中可能也起到重要的作用。体内外实验显示TMVA在动物体内外都具有抗补体活性作用。TMVA上调血小板上DAF和CD59的表达，不同程度地上调白细胞上D胚和CDS夕的表达。TMVA在补体系统中的作用可能与其在异种器宫移植中抗IIAR的发生相关。Mucroqucetin是一个由Q链和p链组成的异二聚体蛋白质，其分子量为25KD。。N一末端氨基酸序列与其它该类蛇毒C一型凝集素样蛋白有很高的同源性。Mucroqucetin呈量效关系延长部分凝血活酶时间（APTT），几乎不影响凝血酶原时间（PT）。因子IX和X的抑制试验显示，该纯化蛋白呈量效关系抑制工X因子的凝血活性，不影响X因子，提示mucroqucetin的抗凝活性主要通过结合FIX而实现，是一个血液凝固IX因子结合蛋白。

Identification and analysis of a Sciaenops ocellatus ISG15 homologue that is involved in host immune defense against bacterial infection

ISG15 is an interferon-stimulated gene that encodes a ubiquitin-like protein. ISG15 homologues have been identified in a number of fish species, some of which are known to be regulated at expression level by virus infection and lipopolysacchande (LPS) treatment However, the relationship between ISG15 and live bacterial infection has not been investigated in piscine models. In this study, an ISG15 homologue, SoISG15, was identified from red drum Scraeriops ocellaws and analyzed at expression and functional levels The open reading frame ofSolSG15 is 477 base pairs (bp) and mtronless, with a 5'-untranslated region (UTR) of 91 bp and a 3'-UTR of 415 bp The deduced amino acid sequence of S0ISG15 shares 60-67% overall identities with the ISG15 of several fish species. S0ISG15 possesses two conserved ubiquinn-like domains and the canonical ubiquitin conjugation motif, LRGG, at the C-terminus. Expressional analysis showed that constitutive expression of SolSG15 was highest in blood and lowest in kidney Experimental challenges with LPS and bacterial pathogens induced significant S0ISG15 expression in the kidney but not in the liver Similar differential induction was also observed at cellular level with primary hepatocytes and head kidney (HK) lymphocytes. Poly(' C), however, effected drastic induction of S0ISG15 expression in kidney and liver at both tissue and cellular levels. Immunoblot analysis showed that S0ISG15 was secreted by cultured HK lymphocytes into the extracellular milieu. Recombinant S0ISG15 expressed in and purified from Eschenclua colt was able to enhance the respiratory burst activity, acid phosphatase activity, and bactericidal activity of HK macrophages. Taken together, the results of this study indicated that SoISG 15 possesses apparent immunological property and is likely to be involved in host immune defense against bacterial infection. (C)2010 Elsevier Ltd All rights reserved.

Cytokinesis proteins Tum and Pav have a nuclear role in Wnt regulation.

Wg/Wnt signals specify cell fates in both invertebrate and vertebrate embryos and maintain stem-cell populations in many adult tissues. Deregulation of the Wnt pathway can transform cells to a proliferative fate, leading to cancer. We have discovered that two Drosophila proteins that are crucial for cytokinesis have a second, largely independent, role in restricting activity of the Wnt pathway. The fly homolog of RacGAP1, Tumbleweed (Tum)/RacGAP50C, and its binding partner, the kinesin-like protein Pavarotti (Pav), negatively regulate Wnt activity in fly embryos and in cultured mammalian cells. Unlike many known regulators of the Wnt pathway, these molecules do not affect stabilization of Arm/beta-catenin (betacat), the principal effector molecule in Wnt signal transduction. Rather, they appear to act downstream of betacat stabilization to control target-gene transcription. Both Tum and Pav accumulate in the nuclei of interphase cells, a location that is spatially distinct from their cleavage-furrow localization during cytokinesis. We show that this nuclear localization is essential for their role in Wnt regulation. Thus, we have identified two modulators of the Wnt pathway that have shared functions in cell division, which hints at a possible link between cytokinesis and Wnt activity during tumorigenesis.

Innate immunogenicity and in vitro protective potential of Schistosoma mansoni lung schistosomula excretory-secretory candidate vaccine antigens

Excretory secretory products (ESP) of Schistosoma mansoni developing larvae are ideal potential vaccines as such molecules may readily induce host primary immune responses, and local memory immune response effectors that would target, surround, and pursue the larvae while negotiating the lung blood capillaries. We herein characterized the cytokines response ESP, e.g., SG3PDH, 14-3-3-like protein, TPX, and calpain induce in the natural context of infection, and defined the global cytokine profile conducive to effective schistosome larvae killing. Accordingly, spleen cells (SC) taken from naive, and 7-, or 9-day S. mansoni-infected mice were stimulated in vitro with the selected ESP, in a recombinant or multiple antigen peptide (MAP) form, and examined for production of T helper type (Th) 1, Th2, and Th17 cytokines, and the ability to mediate in vitro attrition of lung-stage schistosomula. The study indicated that larval ESP principally elicit Th1 and Th17 type cytokines. Recombinant SG3PDH was the only test ESP to additionally activate SC from S. mansoni-infected BALB/c mice to release higher IL-4 levels than unstimulated SC and mediate significant (P

A novel sensor kinase-response regulator hybrid controls biofilm formation and type VI secretion system activity in Burkholderia cenocepacia

Burkholderia cenocepacia is an important opportunistic pathogen causing serious chronic infections in patients with cystic fibrosis (CF). Adaptation of B. cenocepacia to the CF airways may play an important role in the persistence of the infection. We have identified a sensor kinase-response regulator (BCAM0379) named AtsR in B. cenocepacia K56-2 that shares 19% amino acid identity with RetS from Pseudomonas aeruginosa. atsR inactivation led to increased biofilm production and a hyperadherent phenotype in both abiotic surfaces and lung epithelial cells. Also, the atsR mutant overexpressed and hypersecreted an Hcp-like protein known to be specifically secreted by the type VI secretion system (T6SS) in other gram-negative bacteria. Amoeba plaque assays demonstrated that the atsR mutant was more resistant to Dictyostelium predation than the wild-type strain and that this phenomenon was T6SS dependent. Macrophage infection assays also demonstrated that the atsR mutant induces the formation of actin-mediated protrusions from macrophages that require a functional Hcp-like protein, suggesting that the T6SS is involved in actin rearrangements. Three B. cenocepacia transposon mutants that were found in a previous study to be impaired for survival in chronic lung infection model were mapped to the T6SS gene cluster, indicating that the T6SS is required for infection in vivo. Together, our data show that AtsR is involved in the regulation of genes required for virulence in B. cenocepacia K56-2, including genes encoding a T6SS.

A plasma membrane Ca2+-ATPase (PMCA) from the liver fluke, Fasciola hepatica

Fasciolosis is a parasitic infection by the liver fluke Fasciola hepatica, which costs the global agricultural community over US $2 billion per year. Its prevalence is rising due to factors such as climate change and drug resistance. ATP-dependent membrane transporters are considered good potential drug targets as they are essential for cellular processes and are in an exposed, accessible position in the cell. Immunolocalisation studies demonstrated that a plasma membrane calcium ATPase (PMCA) was localised to the parenchymal tissue in F. hepatica. The coding sequence for a F. hepatica PMCA (FhPMCA) has been obtained. This sequence encodes a 1,163 amino acid protein which contains motifs which are commonly conserved in PMCAs. Molecular modelling predicted that the protein has 10 transmembrane segments which include a potential calcium ion binding site and phosphorylation motif. FhPMCA interacts with the calmodulin-like protein FhCaM1, but not the related proteins FhCaM2 or FhCaM3, in a calcium-ion dependent manner. This interaction occurs through a region in the C-terminal region of FhPMCA which most likely adopts an a-helical conformation. When FhPMCA was heterologously expressed in a budding yeast strain deleted for its PMCA (Pmc1p), it restored viability. Microsomes prepared from these yeast cells had calcium ion stimulated ATPase activity which was inhibited by the known PMCA inhibitors, bisphenol and eosin. The potential of FhPMCA as a new drug target is discussed.

The IQGAP-myosin light chain interaction: what is its function?

The first members of the IQGAP family of proteins were
characterised over 15 years ago. It is now known that these molecules act
at the interface between cellular signalling pathways and the actin
cytoskeleton. They bind to a diverse range of signalling molecules –
including those involved in calcium, GTPase, kinase and growth factor
signalling. One intriguing interaction is that between mammalian
IQGAP1 and the myosin essential light chain isoform, Mlc1sa. Although
this has been demonstrated in vitro, its in vivo role is not known. Indeed,
it would be tempting to dismiss it as an experimental artefact, except for
the existence of a parallel interaction in the budding yeast,
Saccharomyces cerevisae. In this organism, the IQGAP-like protein
(Iqg1p) interacts with a myosin essential light chain (Mlc1p). This interaction is critical for the correct execution of cytokinesis. IQGAP-like
proteins also play key roles in cytokinesis in other fungi. Recent work
implicating mammalian IQGAP1 in cytokinesis may help explain the role
of the interaction in higher eukarytotes.

Identification of two focal adhesion targeting sequences in the adapter molecule p130(Cas)

The adapter molecule CAS is localized primarily within focal adhesions in fibroblasts. Because many of the cellular functions attributed to CAS are likely to be dependent on its presence in focal adhesions, this study was undertaken to identify regions of the protein that are involved in its localization. The SH3 domain of CAS, when expressed in isolation from the rest of the protein, was able to target to focal adhesions, whereas a variant containing a point mutation that rendered the SH3 domain unable to associate with FAK remained cytoplasmic. However, in the context of full-length CAS, this mutation did not prevent CAS localization to focal adhesions. Two other variants of CAS that contained deletions of either the SH3 domain alone, or the SH3 domain together with an adjoining proline-rich region, also retained the capacity to localize to focal adhesions. A second focal adhesion targeting region was mapped to the extreme carboxy terminus of CAS. The identification of this second focal adhesion targeting domain in CAS ascribes a previously unknown function to the highly conserved C terminus of CAS. The regulated targeting of CAS to focal adhesions by two independent domains may reflect the important role of CAS within this subcellular compartment.

p130Cas, a substrate associated with v-Src and v-Crk, localizes to focal adhesions and binds to focal adhesion kinase

p130(Cas) (crk associated substrate) has the structural characteristics of an adapter protein, containing multiple consensus SH2 binding sites, an SH3 domain, and a proline-rich domain. The structure of p130(Cas) suggests that it may act to provide a framework for protein-protein interactions; however, as yet, its functional role in cells is unknown. In this report we show that p130(Cas) is localized to focal adhesions. We demonstrate that p130(Cas) associates both in vitro and in vivo with pp125(FAK) (focal adhesion kinase), a kinase implicated in signaling by the integrin family of cell adhesion receptors. p130(Cas) also associates with pp41/43(FRNK) (pp125(FAK)-related, non-kinase), an autonomously expressed form of pp125(FAK) composed of only the C-terminal noncatalytic domain. We show that the association of p130(Cas) with pp125(Fak) and pp41/43(FRNK) is direct, and is mediated by the binding of the SH3 domain of p130(Cas) to a proline-rich sequence present in both the C terminus of pp125(FAK) and in pp41/43(FRNK). In agreement with recent studies we show that p130(Cas) is tyrosine-phosphorylated upon integrin mediated cell adhesion. The association of p130(Cas) with pp125(FAK), a kinase which is activated upon cell adhesion, is likely to be functionally important in integrin mediated signal transduction.

The identification of p130cas-binding proteins and their role in cellular transformation

Adaptor proteins play an important role in signal transduction by regulating the establishment and maintenance of functionally important protein complexes. A recently described member of this group of proteins is p130cas (CAS), which contains numerous sequence motifs predicted to be involved in mediating protein-protein interactions. We propose that adaptor molecules like CAS may help determine the response of a cell to a particular signal by interacting with specific subsets of cellular proteins. To test this hypothesis, we have identified potential binding partners of CAS that may play a rote in cellular transformation by the oncoproteins v-SRC and/or v-CRK. We show that individual domains of CAS associate with specific subsets of proteins in vitro, and that many of these interactions are dependent on the state of tyrosine-phosphorylation of CAS. Sequences necessary for interacting with the focal adhesion kinase pp125FAK (FAK), v-SRC and v-CRK have been mapped to distinct regions of CAS. In addition, the identification of a number of putative CAS-binding partners that are present in crk-transformed cell extracts but undetectable in normal and src-transformed cell extracts supports a model in which unique protein complexes are formed in response to different signals.

BMP signalling: agony and antagony in the family

Bone morphogenetic proteins (BMPs) are secreted extracellular matrix (ECM)-associated proteins that regulate a wide range of developmental processes, including limb and kidney formation. A critical element of BMP regulation is the presence of secreted antagonists that bind and inhibit BMP binding to their cognate Ser/Thr kinase receptors at the plasma membrane. Antagonists such as Noggin, Chordin, Gremlin (Grem1), and twisted gastrulation-1 (Twsg1) have been shown to inhibit BMP action in a range of different cell types and developmental stage-specific contexts. Here we review new developments in the field of BMP and BMP antagonist biology during mammalian development and suggest strategies for targeting these proteins in human disease.

Study of transcripts and reactive oxygen species involved in the defence responses of Quercus suber against Phytophthora cinnamomi

The present work has the merit of exploring an insight into the activation of defence genes of Quercus suber during response to infection by Phytophthora cinnamomi. Thus, cDNA-AFLP methodology was used to identify gene fragments differentially present in the mRNA profiles of host cells of micropropagated Q. suber plantlets roots infected with zoospores of P. cinnamomi at different post challenge time points. Six candidate genes were selected based on their interesting cDNA-AFLP expression patterns and homology to genes known to play a role in defence. These six genes encode a cinnamyl alcohol dehydrogenase 2 (QsCAD2), a protein disulphide isomerase (QsPDI), a CC-NBS-LRR resistance protein (QsRPc), thaumatin-like protein (QsTLP), chitinase (QsCHI) and a 1,3-beta glucanase (QsGLU). The current work has been successful in evaluation of the expression of these genes by qRT-PCR. Data analysis revealed that transcript levels of QsRPc, QsCHI, QsCAD2 and QsPDI increased during the early hours of inoculation, while transcript profiles of thaumatin-like protein showed decreasing. No expression was detected for 1,3-beta-glucanase (QsGLU). Furthermore, the choice of suitable reference genes in any new experimental system is absolutely crucial in qRT-PCR; for this reason in this study and for the first time a set of potential reference genes were analyzed and validated for qRT-PCR normalization in the patho-system Phytophthora-Q. suber. Four candidate reference genes polimerase II (QsRPII), eukaryotic translation initiation factor 5A(QsEIF-5A), b-tubulin (QsTUB) and a medium subunit family protein of Clathrin adaptor complexes (QsCACs) were evaluated to determine the most stable internal references in Q. suber. Analysis of stability of genes was carried out using Genex software. Results indicated all these four potential reference genes assumed stable expression. Data analysis revealed that QsRPII and QsCACs were the two most stable genes, while genes QsTUB and QsEIF-5A were the third and the fourth most stable gene, respectively. In this study, a plasmid-based quantitative PCR method was developed to measure P. cinnamomi colonization during infection process of Q. suber. Plasmid-based detection of P. cinnamomi showed a gradual accumulation of the pathogen DNA in cork oak root tips up to 24 h post infection. The higher increase in P. cinnamomi/plasmid DNA ratio occurred between 18 and 24 h. One of the primary objectives of this research was to study the effect of cinnamomins (elicitins secreted by P. cinnamomin) on inducing defence mechanism against the pathogen, as recent histological and ultra-structural studies showed that P. cinnamomi was restricted to the outer cortex root fragments pre-treated with capsicien and cryptogein, suggesting that elicitins can stimulate plant defence reactions against P. cinnamomi. To complement these studies and to have a clear view of the nature of the interaction, the role of cinnamomins in the production of the oxidative burst [ROS and ROS scavenging enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD)] and in the defence responses was evaluated. Cork oak seedlings were pretreated with alpha-cinnamomin and then inoculated with P. cinnamomi mycelia. Results showed a significant higher production of reactive oxygen species (ROS) (H2O2 and O2•-) in elicitin and non-elicitin treated roots in interaction with P. cinnamomi in comparison to the corresponding control. The plant group inoculated with the pathogen after cinnamomin treatment showed an earlier increase in H2O2 production but this was lower as compared with that group inoculated with P. cinnamomi alone. Also, in elicitin pre-treated group generally, a lower level of O2•− production during infection was observed as compared with inoculated roots with P. cinnamomi alone without elicitin treatment. Furthermore, in this study, we evaluated activities of antioxidant enzymes upon challenge with P. cinnamomi, with and without pretreatment with alpha cinnamomin. Results indicated that the activities of defense enzymes POD, SOD and CAT increased after P. cinnamomi inoculation when compared with those in the control group. Also, in the group treated with alpha-cinnamomin followed by P. cinnamomi inoculation, a higher level of enzymatic activities was detected as compared with elicitin non-treated group, which suggest the protective effect of alpha-cinnamomin against the pathogen due to higher elevated levels of defense enzymes POD, SOD and CAT during the infection period. Furthermore, a sensitive qPCR method was applied to measure the pathogen biomass in elicited and non-elicited Q. suber roots challenged with P. cinnamomi to elucidate the effect of cinnamomins on the colonization of P. cinnamomi. Plasmid-based quantification of P. cinnamomi showed a significant decrease in accumulation of the pathogen DNA in cork oak roots after treatment with alpha and beta-cinnamomins which attest the role of cinnamomins in promoting defense responses in cork oak against P. cinnamomi invasion.