• The Plant Pathology Journal
• /
• 제24권4호
• /
• pp.375-383
• /
• 2008

It is well known that NtMEK2, a tobacco MAPK kinase, is the upstream kinase of both salicylic acid-induced protein kinase and wound-induced protein kinase. In addition, expression of $NtMEK2^{DD}$, a constitutively active mutant of NtMEK2, is known to induce multiple defense responses in tobacco. In this study, transgenic rice plants that contained an active or inactive mutant of NtMEK2 under the control of a steroid inducible promoter were generated and used to determine if a similar MAPK cascade is involved in disease resistance in rice. The expression of $NtMEK2^{DD}$ in transgenic rice plants resulted in HR-like cell death. The observed cell death was preceded by the activation of endogenous rice 48-kDa MBP kinase, which is also activated by Xanthomonas oryzae pv. oryzae, the bacterial blight pathogen of rice. In addition, prolonged activation of the MAPK induced the generation of hydrogen peroxide and up-regulated the expression of defense-related genes including the pathogenesis-related genes, peroxidases and glutathione S-transferases. These results demonstrate that NtMEK2 is functionally replaceable with rice MAPK kinase in inducing the activation of the downstream MAPK, which in turn induces multiple defense responses in rice.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권1호
• /
• pp.57-64
• /
• 2016

Background: Tobacco smoking is considered a risk factor for cervical cancer development due to the presence of tobacco based carcinogenic metabolites in cervical cells of female smokers. In this study, we investigated the role of the T3801C (MspI) polymorphism of CYP1A1, a gene encoding an enzyme necessary for the initiation of tobacco based carcinogen metabolism, on cervical cancer risk. The T to C substitution may alter CYP1A1 activities, potentially elevating cervical cancer risk. Since results of gene-disease association studies vary according to the study population, the multi-ethnic population of Malaysia provides an excellent representative cohort for identifying and comparing the cervical cancer risk among the 3 major ethnics in Southeast Asia in relation to CYP1A1 MspI polymorphism. Materials and Methods: A total of 195 Thin Prep Pap smear samples from HPV negative and cancer free females were randomly selected as controls while 106 formalin fixed paraffin embedded samples from females with invasive cervical cancer were randomly selected for the cases group. The polymorphisms were identified using restriction fragment length polymorphism (RFLP) PCR. Results: We found no significant associations between CYP1A1 MspI polymorphism and cervical cancer in the general Malaysian female population. However, upon ethnic stratification, the variant C/C genotype was significantly associated with a 4.66-fold increase in cervical cancer risk in Malay females (95% CI= 1.21-17.9; p=0.03). No significant association was observed in the Chinese and Indian females. Additionally, there were no significant associations in the dominant model and allele frequency model analysis in both the general and ethnically stratified female population of Malaysia. Conclusions: Our findings suggest that the C/C genotype of CYP1A1 MspI polymorphism is associated with the development of cervical carcinoma in the Malay females of Malaysia.

• The Plant Pathology Journal
• /
• 제31권2호
• /
• pp.195-201
• /
• 2015

Plant growth promoting rhizobacteria (PGPR) are known to confer disease resistance to plants. Bacillus sp. JS demonstrated antifungal activities against five fungal pathogens in in vitro assays. To verify whether the volatiles of Bacillus sp. JS confer disease resistance, tobacco leaves pre-treated with the volatiles were damaged by the fungal pathogen, Rhizoctonia solani and oomycete Phytophthora nicotianae. Pre-treated tobacco leaves had smaller lesion than the control plant leaves. In pathogenesis-related (PR) gene expression analysis, volatiles of Bacillus sp. JS caused the up-regulation of PR-2 encoding ${\beta}$-1,3-glucanase and acidic PR-3 encoding chitinase. Expression of acidic PR-4 encoding chitinase and acidic PR-9 encoding peroxidase increased gradually after exposure of the volatiles to Bacillus sp. JS. Basic PR-14 encoding lipid transfer protein was also increased. However, PR-1 genes, as markers of salicylic acid (SA) induced resistance, were not expressed. These results suggested that the volatiles of Bacillus sp. JS confer disease resistance against fungal and oomycete pathogens through PR genes expression.

• The Plant Pathology Journal
• /
• 제29권3호
• /
• pp.294-304
• /
• 2013

To improve the integrated pest management (IPM) of hot pepper, field study was conducted in Hwasung from 2010 to 2012 and an IPM system was developed to help growers decide when to apply pesticides to control anthracnose, tobacco budworm, Phytophthora blight, bacterial wilt, and bacterial leaf spot. The three field treatments consisted of IPM sprays following the forecast model advisory, a periodic spray at 7-to-10-day intervals, and no spray (control). The number of annual pesticide applications for the IPM treatment ranged from six to eight, whereas the plots subjected to the periodic treatment received pesticide 11 or 12 times annually for three years. Compared to the former strategy, our improved IPM strategy features more intense pest management, with frequent spraying for anthracnose and mixed spraying for tobacco budworm or Phytophthora blight. The incidences for no pesticide control in 2010, 2011, and 2012 were 91, 97.6, and 41.4%, respectively. Conversely, the incidences for the IPM treatment for those years were 7.6, 62.6, and 2%, and the yields from IPM-treated plots were 48.6 kg, 12.1 kg, and 48.8 kg. The incidence and yield in the IPM-treated plots were almost the same as those of the periodic treatment except in 2011, in which no unnecessary sprays were given, meaning that the IPM control was quite successful. From reviewing eight years of field work, sophisticated forecasts that optimize pesticide spray timing reveal that reliance on pesticides can be reduced without compromising yield. Eco-friendly strategies can be implemented in the pest management of hot pepper.

• 한국응용곤충학회지
• /
• 제15권2호
• /
• pp.61-68
• /
• 1976

광교, 동북태, 강림, 육우3호, 은대두등과 같은 대리장려품종이 바이러스에 의하여 심하게 이병되었다. 이 병은 주로 모자익병의 발생이 많은 강원, 경기지방에서 발병이 심하였으나 모자익병이 심하지 않은 전남 등 남부지방에서도 발병되고 있다. 병징으로 보아 tobacco ringspot virus에 의한 대두의 피해와 유사한 것으로 보였으나 지표식물검정과 혈청검정에 의하여 조사한 결과 모두 부정적이었으며 대두품종에 따른 이병정도의 상이, 품종과 접종원에 의한 병징의 변이가 많았다. 이병주에서 분리되는 병징형은 Mottling과 necrosis였으며 지금까지의 연구결과 이 대두병해는 모자익바이러스(SMV)의 계통 내지는 tobacco ringspot virus 이외의 두류바이러스의 복각감염에 의한 것으로 생각할 수 있으나 SMV의 계통에 의한 피해일 가능성이 더욱 유력시되고 있다.

• The Plant Pathology Journal
• /
• 제35권3호
• /
• pp.208-218
• /
• 2019

Here, we reported a novel secreted protein elicitor PeBL2 from Brevibacillus laterosporus A60, which can induce hypersensitive response in tobacco (Nicotiana benthamiana). The ion-exchange chromatography, high-performance liquid chromatography (HPLC) and mass spectrometry were performed for identification of protein elicitor. The 471 bp PeBL2 gene produces a 17.22 kDa protein with 156 amino acids containing an 84-residue signal peptide. Consistent with endogenous protein, the recombinant protein expressed in Escherichia coli induced the typical hypersensitive response (HR) and necrosis in tobacco leaves. Additionally, PeBL2 also triggered early defensive response of generation of reactive oxygen species ($H_2O_2$ and $O_2{^-}$) and systemic resistance against of B. cinerea. Our findings shed new light on a novel strategy for biocontrol using B. laterosporus A60.

• The Plant Pathology Journal
• /
• 제40권1호
• /
• pp.59-72
• /
• 2024

A comprehensive survey of mungbean-growing areas was conducted to observe leaf spot disease caused by Alternaria alternata. Alternaria leaf spot symptoms were observed on the leaves. Diversity of 50 genotypes of mungbean was assessed against A. alternata and data on pathological traits was subjected to cluster analysis. The results showed that genotypes of mungbean were grouped into four clusters based on resistance parameters under the influence of disease. The principal component biplot demonstrated that all the disease-related parameters (% disease incidence, % disease intensity, lesion area, and % of infection) were strongly correlated with each other. Alt a 1 gene that is precisely found in Alternaria species and is responsible for virulence and pathogenicity. Alt a 1 gene was amplified using gene specific primers. The isolated pathogen produced similar symptoms when inoculated on mungbean and tobacco. The sequence analysis of the internal transcribed spacer (ITS) region, a 600 bp fragment amplified using specific primers, ITS1 and ITS2 showed 100% identity with A. alternata. Potato virus X (PVX) -based silencing vector expressing Alt a 1 gene was constructed to control this pathogen through RNA interference in tobacco. Out of 50 inoculated plants, 9 showed delayed onset of disease. Furthermore, to confirm our findings at molecular level semi-quantitative reverse transcriptase polymerase chain reaction was used. Both phenotypic and molecular investigation indicated that RNAi induced through the VIGS vector was efficacious in resisting the pathogen in the model host, Tobacco (Nicotiana tabacum). To the best of our knowledge, this study has been reported for the first time.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권13호
• /
• pp.5439-5444
• /
• 2015

Background: One of the main causes of delay in diagnosis of oral cancer is lack of awareness about aetiology and symptoms among the general population. The aim of this study was to assess the knowledge and practice of patients regarding oral cancer and their attitude towards tobacco cessation. Materials and Methods: This study was carried out in Isfahan-Iran in 2014. A 29-item self-administrated questionnaire was designed and piloted and distributed to patients attending dental clinics. Questions were focused on awareness about oral cancer risk factors, signs and symptoms, places in the mouth which are more susceptible and attitude toward tobacco cessation. Chi-square, T-test, ANOVA and logistic regression tests were used for statistical analysis. Results: A total of 546 valid completed questionnaires were obtained. The mean knowledge score of patients was 4.1(${\pm}2.7$) out of 13. Some 80% of patients did not know about early manifestations of oral cancer. Only 18% knew the most likely sites of oral cancer. Only 43.1% and 65.2% of patients reported alcohol and tobacco consumption as the main risk factors but they had a fair knowledge about other risk factors. There was no significant difference in Knowledge level between patients regarding their sex, educational levels and age. Most patents (90%) expected their dentists to warn them about the harmful effects of smoking and showed willingness to quit if recommended. Conclusions: Knowledge about oral cancer was found to be quite low. It seems necessary to increase the level of public awareness using educational programs with cooperation of dentists in tobacco cessation programs.

• Journal of Microbiology and Biotechnology
• /
• 제18권6호
• /
• pp.1095-1100
• /
• 2008

The role of exopolysaccharides (EPSs) from a plant growth-promoting rhizobacterium, Burkholderia gladioli IN26, on elicitation of induced systemic resistance was investigated. A purified EPS induced expression of PR-1a::GUS on tobacco and elicited induced resistance against Colletotrichum orbiculare on cucumber. The maximum level of disease protection was noted when seeds were soaked in 200 ppm of the EPS. Our results indicate that EPS from specific rhizobacteria can elicit induced resistance and suggest that bacterial EPS might be a useful elicitor of resistance under field conditions.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권15호
• /
• pp.6439-6444
• /
• 2015

Background: In India smokeless tobacco users account for 25.9% of total tobacco use, Gutkha being the most common form. This study evaluated the association between serum lipid profile and Gutkha use as an early diagnostic and/or prognostic indicator for oral submucous fibrosis (OSMF) and oral cancer (Oral Ca) in non-smokers and non-alcohol consumers. Materials and Methods: A total of 163 participants were recruited from two sites in India. Participants were divided into four groups: individuals without any Gutkha chewing habit and without any oral lesions (control group), individuals with Gutkha chewing habit but without any oral lesions (GWL), patients with a confirmed clinical diagnosis of OSMF, and patients with a confirmed diagnosis of Oral Ca. Mixed linear modelling (MLM) was conducted to detect the change in mean serum lipid levels among four groups. Results: The sample consisted of 69% males and 31% females. Results of MLM show an inverse relationship between serum lipid levels in OSMF, and Oral Ca groups when compared to the control group. Conclusions: The results of our study demonstrated that GWL, OSMF and Oral Ca patients had lower serum lipid levels. Low serum lipid levels could be an indicator of initial neoplastic changes in oral cancer.