• The Plant Pathology Journal
• /
• 제30권2호
• /
• pp.168-177
• /
• 2014

Plant has possessed diverse stress signals from outside and maintained its fitness. Out of such plant responses, it is well known that mitogen-activated protein kinase (MAPK) cascade plays important role in wounding and pathogen attack in most dicot plants. However, little is understood about its role in wounding response for the economically important monocot rice plant. In this study, therefore, the involvement of MAPK was investigated to understand the wounding signaling pathway in rice. The OsMPK1 was rapidly activated by wounding within 10 min, and OsMPK1 was also activated by challenge of rice blast fungus. Further analysis revealed that OsMKK4, the upstream kinase of OsMPK1, phosphorylated OsMPK1 by wounding in vivo. Furthermore, OsMPK1 directly interacted with a rice defense-related transcription factor OsWRKY53. To understand a functional link between MAPK and its target transcription factor, we showed that OsMPK1 activated by the constitutively active mutant $OsMKK4^{DD}$ phosphorylated OsWRKY53 in vitro. Taken together, components involving in the wounding signaling pathway, OsMKK4-OsMPK1-OsWRKY53, can be important players in regulating crosstalk between abiotic stress and biotic stress.

• Molecules and Cells
• /
• 제19권2호
• /
• pp.228-231
• /
• 2005

Recent characterization of several genes involved in plant defense responses suggested that ubiquitin-mediated protein degradation has a role in these responses. We isolated two cDNAs (NtUBA1 and NtUBA2) encoding ubiquitin-activating enzyme (E1) from Nicotiana tabacum cv. BY-2. The open reading frames of both encoded 1080 amino acids, corresponding to molecular masses of 120 kDa. The E1s and corresponding transcripts were upregulated by infection with tobacco mosaic virus (TMV) and tomato mosaic virus (ToMV), and to a lesser extent by cucumber mosaic virus (CMV). Furthermore, they were also upregulated by wounding stress, and the plant hormones salicylic acid, jasmonic acid and the ethylene precursor, aminocyclopropane-1-carboxylic acid (ACC). Our findings support the idea that the ubiquitin-proteasome system plays a role in plant disease defenses.

• The Plant Pathology Journal
• /
• 제25권2호
• /
• pp.172-178
• /
• 2009

To obtain global gene expression profiles of Arabidopsis thaliana by acid stress, seedlings were subjected to low pH stress. Using Affymetrix AH1 chips covering 24,000 genes, we analyzed gene expression patterns. Fifty-four genes were up-regulated, and 38 were down-regulated more than 3-fold after 2 h of acid stress (pH 3.0). Several defense and abiotic stress-related genes were recognized among the up-regulated genes and peroxidase and extensin genes were identified among the down-regulated genes. After 12 h treatment, relatively fewer genes showed changed expression, indicating that plants seem to adjust themselves to this abiotic stress. Most of the up-regulated genes are already known to be involved in abiotic stress responses and pathogen attacks, especially wounding. However, down-regulated genes for the members of extensins and peroxidases are specific to the acid treatment. These results suggest that acid treatment turns on genes involved in stress responses, especially in wounding and turns off genes very specific for the acid stress.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제19권2호
• /
• pp.229-235
• /
• 2009

We have cloned and characterized a lipocalin from the bumblebee Bombus ignitus (Bi-lipocalin). The Bi-lipocalin gene spans 2284 bp and consists of four exons coding for 270 amino acid residues. Sequence analysis revealed that Bi-lipocalin possesses three structurally conserved regions (SCTs) that characterize lipocalins. Recombinant Bi-lipocalin, expressed as a 37 kDa protein in baculovirus-infected insect cells, was N-glycosylated, indicating that the carbohydrate moieties are necessary for secretion. Tissue distribution analysis revealed ubiquitous expression of Bi-lipocalin in all tissues examined. Bi-lipocalin transcripts were upregulated by stress, such as wounding, $H_2O_2$ exposure, and external temperature shock. These results indicate that Bi-lipocalin is a stress-inducible protein that acts on wounding, $H_2O_2$ overexposure and temperature stimulation.

• 한국환경과학회지
• /
• 제8권6호
• /
• pp.669-676
• /
• 1999

The effects of wounding and jasmonic acid(JA) on polyphenol oxidase(PPO) in tomato(Lycopersicon esculentum Mill.) seedlings were investigated. PPO was strongly induced by wounding or JA, and the response was also shown to be systemically induced by wounding. Mechanical wounding in cotyledon or leaf produced a signal that caused the concentration of PPO to increase in the unwounded cotyledon, in the first leaves but not in the second leaves. Severity of wounding and light intensity also affected wound induced change in PPO activity, JA showed a stimulatory effect on the loss of chlorophyll and the rapid increase in PPO activity. The PPO was clearly more active in the wounded leaves than in controls. The potency and specificity of the JA indicate a close relationship between JA and wound-induced changes in PPO in tomato species. JA and abscisic acid(ABA) acted similarly on both unwounded and wounded leaves, but the amount of PPO in the wounded leaves was always more than the respective controls. The highest increase in PPO activity occurred in woundand JA-induced leaves of seedlings kept under bright lighting. Benzyladenine(BA) completely abolished JA- and ABA-induced PPO activity. The results suggest that JA-induced PPO activity is due to de novo PPO synthesis. Histochemical tests for PPO in stems of wound- and JA -treated tomato plants indicate that PPO was localized primarily, in the. outer .cortex . and xylem parenchyma. It is concluded that exogenously applied JA acts as stress agents and PPO may be a component of the inducible anti-hervivore defense response.

• Applied Microscopy
• /
• 제27권2호
• /
• pp.121-130
• /
• 1997

It has been demonstrated that majority of cells in the mammalian body such as myocytes and epithelial cells of skin and intestine respond to mechanical force or environmental factors and exhibit partial disruption of cell membrane, i. e., cell wounding, even in a physiological condition. Myocardial cells are rather apt to be wounded than other cells since they are definitely exposed to mechanical stress by contraction-relaxation and blood flow. However, the mechanism how myocardial cells protect themselves against cell wounding is not yet clarified. On this background, the present study was performed to elucidate whether albumin leakage is related to cell wounding and to assess whether diltiazem, a potent calcium channel blocker, is beneficial in isoproterenol-induced cell wounding in the heart. Hearts isolated from New Zealand White rabbits ($1.5\sim2.0kg$ body weight, n=20) were perfused with Tyrode solution by Langendorff technique. After stabilization of baseline hemodynamics, the hearts were subjected to bolus administration of isoproterenol and diltiazem as following order: $1.6{\mu}M$ isoproterenol at zero min (the beginning point): $16{\mu}M$ diltiazem at 20min; $1.6{\mu}M$ isoproterenol at 25min; $16{\mu}M$ isoproterenol at 45 min; $160{\mu}M$ diltiazem at 65 min; $16{\mu}M$ isoproterenol at 70 min. During all experiments, the left ventricular function was recorded, albumin leakage in the coronary effluents was analyzed by electrophoresis and Western blot, and myocardial cell membranes were examined by conventional transmission electron microscopy. Data were analyzed by t-test and linear regression test. Isoproterenol significantly increased the inotropic and chronotropic contractions, coronary flow, and frequency of arrhythmia, however, diltiazem did not influence on hemodynamics except decrease in the frequency of arrhythmia and a slight decrease in contractility. Isoproterenol also resulted partial disruption of myocardial cell membrane and inclose in albumin leakage, while diltiazem pretreatment showed number of electron-dense plaques in the cell membrane and a tendency of decrease in albumin leakage. These results indicate that albumin leakage may be an indirect index of cell wounding in the heart and diltiazem nay be beneficial to protect myocardial cells against isoproterenol-induced cell wounding. It is likely that diltiazem promotes resealing process of the cell membrane.

• BMB Reports
• /
• 제42권7호
• /
• pp.439-443
• /
• 2009

Dehydrins are group II, late embryogenesis abundant proteins that act putatively as chaperones in stressed plants. To elucidate the function of dehydrins in poplar, we isolated the $SK_2$-type dehydrin gene Podhn from Populus alba $\times$ P. tremula var. glandulosa suspension cells and analyzed its expression following treatments of abiotic stress, wounding and plant growth regulator. Sequence homology and phylogenetic analyses indicate Podhn encodes an acidic dehydrin (pI 5.14, 277 amino acids, predicted size 25.6 kDa) containing two lysine-rich "K-segments" and a 7-serine residue "S-segment", both characteristic of $SK_2$-type dehydrins. Southern blots show Podhn genes form a small gene family in poplar. Podhn was expressed in all tissues examined under unstressed conditions, but most strongly in cell suspensions (especially in the stationary phase). Drought, salt, cold and exogenous abscisic acid (ABA) treatments enhanced Podhn expression, while wounding and jasmonic acid caused its reduction. Therefore, Podhn might be involved in ABA or stress response.

• 생명과학회지
• /
• 제12권3호
• /
• pp.274-280
• /
• 2002

Phenylpropanoid pathway 생성물질은 식물의 self-defense에 관계하며 이러한 물질들은 UV뿐 아니라 wounding, pathogen과 같은 environmental stress에 의해 생성되는 것으로 알려져 있다. 벼에서 PAL mRNA 는 UV 조사 후 12시간에서 48시간까지는 증가하였으나 48시간부터 60시간까지는 점점 줄어드는 경향을 보였다. 한편 PAL의 활성은 UV조사 후 24시간에서 가장 높았지만 상처에 의해서는 PAL의 활성이 벼에서는 증가하지 않았다. 그러나 고추에서는 UV조사와 상처를 준 후 24시간과 10시간에서 각각 높은 활성을 나타내었다. 벼와 고추 모두 cinnamic acid 4-hydroxylase의 활성은 상처를 준 후 12시간에서 증가하였지만 UV 조사는 C4H 활성에 영향을 주지 않았다. 이러한 결과로 볼 때 벼와 고추에서는 UV 조사와 상처가 모두 PAL, C4H 효소활성에 영향을 주는 것으로 나타났다.

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
• /
• pp.206.1-206
• /
• 1999

No Abstract, See Full Text

• The Plant Pathology Journal
• /
• 제17권6호
• /
• pp.376.3-376
• /
• 2001