52 research outputs found

    Transcriptome analysis reveals new insight into appressorium formation and function in the rice blast fungus Magnaporthe oryzae

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    Analysis of genome-wide gene-expression changes during spore germination and appressorium formation in Magnaporthe oryzae revealed that protein degradation and amino-acid metabolism are essential for appressorium formation and subsequent infection

    Diverse and tissue-enriched small RNAs in the plant pathogenic fungus, Magnaporthe oryzae

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    <p>Abstract</p> <p>Background</p> <p>Emerging knowledge of the impact of small RNAs as important cellular regulators has prompted an explosion of small transcriptome sequencing projects. Although significant progress has been made towards small RNA discovery and biogenesis in higher eukaryotes and other model organisms, knowledge in simple eukaryotes such as filamentous fungi remains limited.</p> <p>Results</p> <p>Here, we used 454 pyrosequencing to present a detailed analysis of the small RNA transcriptome (~ 15 - 40 nucleotides in length) from mycelia and appressoria tissues of the rice blast fungal pathogen, <it>Magnaporthe oryzae</it>. Small RNAs mapped to numerous nuclear and mitochondrial genomic features including repetitive elements, tRNA loci, rRNAs, protein coding genes, snRNAs and intergenic regions. For most elements, small RNAs mapped primarily to the sense strand with the exception of repetitive elements to which small RNAs mapped in the sense and antisense orientation in near equal proportions. Inspection of the small RNAs revealed a preference for U and suppression of C at position 1, particularly for antisense mapping small RNAs. In the mycelia library, small RNAs of the size 18 - 23 nt were enriched for intergenic regions and repetitive elements. Small RNAs mapping to LTR retrotransposons were classified as LTR retrotransposon-siRNAs (LTR-siRNAs). Conversely, the appressoria library had a greater proportion of 28 - 35 nt small RNAs mapping to tRNA loci, and were classified as tRNA-derived RNA fragments (tRFs). LTR-siRNAs and tRFs were independently validated by 3' RACE PCR and northern blots, respectively.</p> <p>Conclusions</p> <p>Our findings suggest <it>M. oryzae </it>small RNAs differentially accumulate in vegetative and specialized-infection tissues and may play an active role in genome integrity and regulating growth and development.</p

    Sistem Kontrol Kekeruhan dan Temperatur Air Laut Menggunakan Microcontroller Arduino Mega

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    Sistem kontrol merupakan bagian yang tidak dapat dipisahkan dalam kehidupan sehari-hari.. Saat ini penerapan sistem kontrol telah menjamah bidang perkebunan, perikanan ataupun pertanian. Dalam penelitian ini, sistem kontrol akan diterapkan pada proses budidaya perikanan seperti budidaya ikan kerapu. Dimana ikan kerapu memiliki habitat dengan kondisi air laut dengan kadar garam 30 - 33 ppt, kadar oksigen ± 4 ppm, temperatur air laut 240 - 310C dan kadar keasaman (pH) air laut 7,6 - 7,8. Kecepatan arus air ideal sekitar 20 hingga 40 cm/detik dimana diperlukan untuk pergantian air dan oksigen serta untuk mengalirkan sisa metabolisme ikan serta pakan ikan keluar. Kondisi habitat ikan ini harus dpat dikontrol dengan baik. Di beberapa tempat budidaya ikan kerapu sistem penjagaan kondisi habitat ini dilakukan secara manual. Dengan adanya sistem kontrol, kondisi habitat ini akan sangat mudah dijaga. Dimana dalam penelitian ini difokuskan pada kemampuan sistem kontrol kekeruhan dan temperatur air laut meliputi fungsi sensor, waktu kerja pengontrol dan kinerja peralatan kontrol. Perangkat pengontrol menggunakan microcontroller Arduino Mega dengan beberapa sensor temperatur dan kekeruhan. Sensor temperatur menggunakan tipe DS18S20 dan untuk kontrol kekeruhan menggunakan sensor turbidity. Dari hasil pengujian didapatkan bahwa sistem kontrol ini dapat mengatur dan menjaga kadar kekeruhan dan temperatur air laut dengan arus 0.215 A untuk satu relay dan 0.33 A untuk 3 relay. Untuk kekeruhan dibutuhkan waktu yang dibutuhkan untuk kontrol aktif yaitu 15 detik dengan indikator kekeruhan dari pakan ikan sebanyak 50 gram dan 10 liter air. Untuk kapasitas yang lain 15 liter air didapatkan waktu kontrol aktif pada 40 detik dengan jumlah pakan 50 gram. Hal ini menunjukkan kontrol kekeruhan bekerja dengan baik dengan semakin keruh air laut semakin cepat bekerja sistem kontrol menggantikan air laut untuk tetap menjaga habitatnya. Waktu yang dibutuhkan untuk menurukan temperatur 1.270C adalah 6 menit 37 detik dengan kapasitas 10 lite

    Predictors of paravalvular aortic regurgitation after surgery for Behcets disease-related severe aortic regurgitation

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    Background Behcets disease (BD)-related aortic regurgitation (AR) is known to be associated with paravalvular leakage (PVL) after successful aortic valve (AV) surgery. This study aimed to determine predictors of PVL after successful AV surgery in BD patients. We retrospectively collected data of 35 patients (42.1 ± 9.1 years, 27 men) who underwent surgery for severe BD-related AR at two tertiary centers. The diagnosis was established based on echocardiographic, surgical, and/or pathological findings in conjunction with the International Study Group criteria for BD. A total of 76 cases of AV surgery in 35 patients were analyzed. Results A median follow-up duration was 8.0 years (interquartile range, 5.4–14.3 years). PVL developed in 18 patients (51.4%) within 2 years after the first surgery. Six patients who met the diagnostic criteria for BD did not develop PVL, in whom 5 patients took immunosuppressive therapy (IST). However, 4 of 9 patients (44.4%) who did not meet the diagnostic criteria developed PVL, in whom four (44.4%) patients took IST. On multivariable analysis, postoperative IST and concomitant aortic root replacement (ARR) were two independent predictors for less PVL development (HR 0.38, 95% CI 0.17–0.89, p = 0.025 for postoperative IST; HR 0.17, 95% CI 0.08–0.36, p < 0.001 for concomitant ARR). Preoperative IST use did not determine PVL development (p = 0.75). Conclusions Postoperative, but not preoperative, IST and concomitant ARR were independent predictors of less development of PVL. Special attention is required for early diagnosis BD-related AR, especially in patients not satisfying the current diagnostic criteria

    Combining ChIP-chip and Expression Profiling to Model the MoCRZ1 Mediated Circuit for Ca2+/Calcineurin Signaling in the Rice Blast Fungus

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    Significant progress has been made in defining the central signaling networks in many organisms, but collectively we know little about the downstream targets of these networks and the genes they regulate. To reconstruct the regulatory circuit of calcineurin signal transduction via MoCRZ1, a Magnaporthe oryzae C2H2 transcription factor activated by calcineurin dephosphorylation, we used a combined approach of chromatin immunoprecipitation - chip (ChIP-chip), coupled with microarray expression studies. One hundred forty genes were identified as being both a direct target of MoCRZ1 and having expression concurrently differentially regulated in a calcium/calcineurin/MoCRZ1 dependent manner. Highly represented were genes involved in calcium signaling, small molecule transport, ion homeostasis, cell wall synthesis/maintenance, and fungal virulence. Of particular note, genes involved in vesicle mediated secretion necessary for establishing host associations, were also found. MoCRZ1 itself was a target, suggesting a previously unreported autoregulation control point. The data also implicated a previously unreported feedback regulation mechanism of calcineurin activity. We propose that calcium/calcineurin regulated signal transduction circuits controlling development and pathogenicity manifest through multiple layers of regulation. We present results from the ChIP-chip and expression analysis along with a refined model of calcium/calcineurin signaling in this important plant pathogen

    Current Status of Early Blight Resistance in Tomato: An Update

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    Early blight (EB) is one of the dreadful diseases of tomato caused by several species of Alternaria including Alternaria linariae (which includes A. solani and A. tomatophila), as well as A. alternata. In some instances, annual economic yield losses due to EB have been estimated at 79%. Alternaria are known only to reproduce asexually, but a highly-virulent isolate has the potential to overcome existing resistance genes. Currently, cultural practices and fungicide applications are employed for the management of EB due to the lack of strong resistant cultivars. Resistance sources have been identified in wild species of tomato; some breeding lines and cultivars with moderate resistance have been developed through conventional breeding methods. Polygenic inheritance of EB resistance, insufficient resistance in cultivated species and the association of EB resistance with undesirable horticultural traits have thwarted the effective breeding of EB resistance in tomato. Several quantitative trait loci (QTL) conferring EB resistance have been detected in the populations derived from different wild species including Solanum habrochaites, Solanum arcanum and S. pimpinellifolium, but none of them could be used in EB resistance breeding due to low individual QTL effects. Pyramiding of those QTLs would provide strong resistance. More research is needed to identify additional sources of useful resistance, to incorporate resistant QTLs into breeding lines through marker-assisted selection (MAS) and to develop resistant cultivars with desirable horticultural traits including high yielding potential and early maturity. This paper will review the current understanding of causal agents of EB of tomato, resistance genetics and breeding, problems associated with breeding and future prospects

    Comparative proteomic analysis between nitrogen supplemented and starved conditions in Magnaporthe oryzae

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    Abstract Background Fungi are constantly exposed to nitrogen limiting environments, and thus the efficient regulation of nitrogen metabolism is essential for their survival, growth, development and pathogenicity. To understand how the rice blast pathogen Magnaporthe oryzae copes with limited nitrogen availability, a global proteome analysis under nitrogen supplemented and nitrogen starved conditions was completed. Methods M. oryzae strain 70–15 was cultivated in liquid minimal media and transferred to media with nitrate or without a nitrogen source. Proteins were isolated and subjected to unfractionated gel-free based liquid chromatography-tandem mass spectrometry (LC-MS/MS). The subcellular localization and function of the identified proteins were predicted using bioinformatics tools. Results A total of 5498 M. oryzae proteins were identified. Comparative analysis of protein expression showed 363 proteins and 266 proteins significantly induced or uniquely expressed under nitrogen starved or nitrogen supplemented conditions, respectively. A functional analysis of differentially expressed proteins revealed that during nitrogen starvation nitrogen catabolite repression, melanin biosynthesis, protein degradation and protein translation pathways underwent extensive alterations. In addition, nitrogen starvation induced accumulation of various extracellular proteins including small extracellular proteins consistent with observations of a link between nitrogen starvation and the development of pathogenicity in M. oryzae. Conclusion The results from this study provide a comprehensive understanding of fungal responses to nitrogen availability
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