본 연구는 딸기에서 발생하는 흰가루병 방제에 사용되는 살균제의 잔류시험을 수행하고 회귀방정 식 및 생물학적 반감기를 산출하여 한국과 일본, Codex의 잔류허용기준에 근거한 농약의 사용 및 안전한 농산물 생산에 기여하고자 수행되었다. 딸기재배 중 흰가루병 방제용 주요 살균제 boscalid, kresoxim-methyl, pyraclostrobin, pyrimethanil을 각 농약의 안전사용기준에 따라 기준량 1회 살포 후 1, 3, 5, 7, 9, 11, 13일에 딸기 시료를 채취하여 QuEChERS법을 이용하여 추출하고, NH2 SPE 카 트리지로 정제하여 HPLC/DAD로 분석하였다. 시험농약의 검출한계 및 정량한계는 4성분의 농약에서 모두 0.01과 0.03mg/kg이었으며, 평균회수율은 92.9~99.2%, 상대표준편차는≤5%로 산출되었다. 딸기 중 boscalid, kresoxim-methyl, pyraclostrobin, pyrimethanil의 생물학적 반감기는 기준량처리 시 각각 6.2, 4.0, 6.1, 6.6일로 나타났다. 이러한 결과로, 시설재배지 딸기 흰가루병 방제를 위해 사용되는 살균제의 안전 사용을 통해 국내 및 주요 수출국가의 MRL을 초과하지 않는 안전한 딸기를 생산하는데 기여할 것으로 기대된다.

When the rice blast fungus attacks rice, fungal proteins are secreted into the plant apoplast to facilitate infection. The rice plant recognizes such secreted proteins, which result in the induction of defense responses. However, the molecular mechanisms of how rice plant recognizes secreted proteins remain elusive. Here, we report that a small, secreted protein, Magnaporthe oryzae snodprot1 homolog (MSP1), is recognized by rice plants and triggers host cell death and defense responses. Furthermore, pre-treatment of rice with Domain II, elicitor-active epitope of MSP1, induces resistance to the pathogen KJ301. We demonstrated that secretion of MSP1 into the apoplast is prerequisite for triggering cell death and activating defense-related gene expression, suggesting that it is recognized by a receptor in the host plasma membrane. Through comprehensively analysis of transcriptional profile in rice leaves and suspension cultured cells (SCCs) in response to exogenous MSP1 and Domain II treatment using 60K Agilent microarray chip, we found that 27 signaling genes, such as F-box(6), MAPK(4), protein kinase(11), transcription factor(6), were up-regulated in leaves and SCCs and six protein kinases were targeted into plasma membrane. Thus, we suggest that some of these genes may act as receptor of MSP1 in response to exogenous MSP1 treatment. Expression pattern of candidate genes was further checked in response to different environment cues using open rice data. These results demonstrate that these genes may be also involved in the signaling in response to cold stress, root-JA treatment and brown plant hopper (BPH) attack.

Understanding the host defense mechanisms in response to brown leaf spot disease caused by Cochliobolus miyabeanus is very important for production of resistant plant. In this study, two-dimensional gel electrophoresis (2-DGE) in conjunction with mass spectrometry was utilized to unravel changes of stress inducible proteins in rice leaves infected with C. miyabeanus. For this purpose, we firstly observed disease developmental process of C. miyabeanus in rice using trypan blue, anilin blue, acid fuchsin staining, and DAB staining for ROS detection and expressional abundance of ROS related proteins in rice leaves inoculated was confirmed by Western blotting. Proteins were extracted by PEG fractionation and their expression patterns were analyzed by 2-DGE and subjected to image analysis using the ImageMaster 6.0 2D Platinum software, resulting in the identification of 86 differentially expressed protein spots with significantly changes (p<0.05) compared with control. MALDI-TOFTOF-MS analysis revealed that 69 proteins including 42 and 27 significantly up- and down-regulated proteins, respectively, were identified. Based on gene ontology analysis, identified proteins were classified according to their functional groups: metabolism (20%), oxygen-detoxifying (13%), protein stress/defense (24%). Thus, these results for the first time suggest that differentially induced proteins may play a key role for understanding host defense mechanisms during rice -C. miyabeanus interaction.

The rice blast disease caused by Magnaporthe oryzae (M. oryzae) is one of the most serious diseases of cultivated rice (Oryza sativa L.) in most rice-growing regions of the world. In order to investigate early responsible genes in rice in response to M. oryzae, we analyzed transcriptomics analysis using 300 K tilling microarray chip. The quality of RNA samples was initially validated by 4 defense related genes and phytoalexins measurement using RT-PCR and HPLC, respectively, which are well known defense markers. We determined that accumulation of 608 genes showed statistically significant changes in the level of transcription (>2 fold change, P<0.05). Among them, 261 genes were more up-regulated in incompatible interaction than that of compatible one. We further analyzed GO enrichment analysis of the 41 and 231 which were 2 fold up-regulated genes at 12h and 48h in incompatible interaction, respectively, using Rice Oligo nucleotide Array Database (http://ricearray.org). Furthermore, MapMan analysis (http://mapman.gabipd.org/) revealed that 21 and 85 genes including 18 receptor-like genes which were more induced in incompatible interaction compared to compatible interaction were found to be involved in biotic stress. Thus, this study suggests that early inducible genes including receptor-like protein kinases in incompatible interaction may play a key role in disease resistance against M. oryzae attacks.

Here, we first demonstrate that identification of rice brown spot disease fungus (Cochliobolus miyabeanus, C. miyabeanus) proteins is possible in infected tissues using in planta apoplastic proteome with non-destructive tissues. In planta apoplastic proteins from rice leaves inoculated with C. miyabeanus, CM2 (compatible race), were isolated by vacuum infiltration with CaCl2/Na-acetateextractionbuffer, separated by SDS-PAGE, and identified by MudPIT. Of the 529 proteins that were identified by MudPIT, a large proportion (490) was from the rice. Numerous carbohydrate metabolic process (48), oxidation and reduction (44), response to oxidative stress (20%) were identified and confirmed their expression at RNA levels using microarray. Bioinformatic analysis showed that 176 and 39 of these proteins have a signal peptide in rice and rice brown spot fungus, respectively, using Signal P. The large proportion of proteins interestingly identified from the in planta apoplast were involved inprotease, hydrophobin, and host cell wall hydrolysis (Xylanase, beta-glucosidase) derived from pathogen. Thus, we suggest that in planta rice apoplastic secretome will be an important clue to understand the rice-rice brown spot fungus interactions.

A population ofrecombinant inbred lines derived from a cross between Ilpumbyeo, a blast-susceptibleyopowca cultivarofhigh eating-quality and high yield potential, and GL33, a blast-resistance/apowca weedy rice was used to identifv QTLs affect-ing importan

Four different rice varieties, Sindongjinbyeo, Dongjin #1, Saegyehwabyeo, and Iksan 467, were transplanted under three different nitrogen levels and two different seedling numbers per hill to obtain basic information on panicle traits under different cultural conditions and to propose the ideal panicle structure in Japonica rice. Sindongjinbyeo and Iksan 467 were characterized by more primary rachis branches (PRBs) per panicle and more grains on PRB than other cultivars. The two varieties also had fewer secondary rachis branches (SRBs) per PRB and fewer grains on SRB per PRB. These characteristics, consequently, resulted in higher ripened grain rate, contrary to that of Dongjin #1 and Saegyehwabyeo. In the correlation coefficient analysis, PRB number per panicle and grain number on PRB per panicle were positively correlated with ripened grain rate, while SRB number per panicle, number of grains on SRB per panicle, SRB number per PRB, number of grains on SRB per PRB and grain number per panicle were negatively correlated with ripened grain rate. Therefore, the number of grains on PRB per panicle, SRB number per PRB and the number of grains on SRB per PRB were the appropriate criteria for determining and achieving higher ripened grain rate in rice. High ripened grain rate over 90% was obtainable with over 12.5 PRBs per panicle and 63 grains on PRB per panicle, and with under 1.7 SRBs per PRB, 5 grains on SRB per PRB, 130 grains per panicle, and 14 panicles per hill. The study recommended that for over 90% high ripened grain rate, the critical limiting factors should be under 2 SRBs per PRB, 6 grains per PRB, and 130 grains per panicle, irrespective of the PRB number per panicle and the number of grains on PRB.