ManR,a Transcriptional Regulator of the β-Mannan Utilization System,Controls the Cellulose Utilization System in Aspergillus oryzae

The author modified a respiratory gas analyzer to analyze the respiratory ¹³CO₂ of 12 small laboratory animals all at once. To investigate the practical use of this system, mice were orally (OR) or intravenously (IV) given glucose solutions containing three different amounts of ¹³C-labeled glucose. Expired ¹³CO₂ derived from exogenous glucose was detected within 10 minutes after administration in OR mice, but about 30 minutes in IV mice. The height of the peak of ¹³CO₂ expiration was correlated with the administered ¹³C-glucose mass.     

SOBIR1 and AGB1 independently contribute to nonhost resistance to Pyricularia oryzae (syn. Magnaporthe oryzae) in Arabidopsis thaliana

ABSTRACT

Rice blast caused by Pyricularia oryzae (syn. Magnaporthe oryzae) is a disease devastating to rice. We have studied the Arabidopsis-P. oryzae pathosystem as a model system for nonhost resistance (NHR) and found that SOBIR1, but not BAK1, is a positive regulator of NHR to P. oryzae in Arabidopsis. AGB1 is also involved in NHR. However, the genetic interactions between SOBIR1, BAK1, and AGB1 are uncharacterized. In this study, we delineated the genetic interactions between SOBIR1, BAK1, and AGB1 in NHR to P. oryzae in Arabidopsis and found SOBIR1 and AGB1 independently control NHR to P. oryzae in Arabidopsis pen2-1 mutant plants. Furthermore, XLG2, but not TMM, has a positive role in penetration resistance to P. oryzae in Arabidopsis pen2-1 mutant plants. Our study characterized genetic interactions in Arabidopsis NHR.

Abbreviations: PRR: pattern recognition receptor, RLK: receptor-like kinase, RLP: receptor-like protein, BAK1: BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1, BIR1: BAK1-INTERACTING RECEPTOR-LIKE KINASE 1, SOBIR1: SUPPRESSOR OF BIR1-1-1, AGB1: ARABIDOPSIS G PROTEIN ß-SUBUNIT 1, XLG2: EXTRA-LARGE G PROTEIN 2     

Synthesis of Sphingosine Analogs with Acyclic Terpenoidal Carbon Skeleton

A simple and general synthetic method is described for erythro- and threo-forms of 2-amino-1,3-diols with an acyclic terpenoid-type side chain. ¹³C-NMR data are given for the triacetyl and N-acetyl derivatives of the synthetic erythro- and threo-2-amino-1,3-diols.     

Studies on a Quantitative Analysis of Oryzalides and Oryzalic Acids in Rice Plants by GC-SIM

A procedure for the quantitative analysis of oryzalides and oryzalic acids in leaves of rice cultivars was established by using GC-MS-selective ion monitoring (GC-SIM), 17-deuterated oryzalide B being used as an internal reference. The total contents of four compounds of oryzalides and oryzalic acids in the leaves at three different growth stages of Norin-27, i.e., seedling, tillering, and ripening, showed values of 5.3, 17.9, and 37.9 μg/g, respectively. The contents of oryzalides and oryzalic acids in each organ, i.e., leaf, stem, ear, and root, showed values of 35.0 and 1.7 μg/g for the former two, respectively, and were not detectable for the latter two. A preliminary analysis of Norin-27 and Rantai emas leaves inoculated with an incompatible and compatible strain of Xanthomonas campestris pv. oryzae showed a greater accumulation of oryzalides and oryzalic acids, especially in the lesion area, than the figures for healthy leaves. Mechanical injury by a needle-bundle also increased the total amounts.     

Evaluation of modified chitosan as matrix for hydrophobic interaction chromatography

Chitosan beads were modified with glutaraldehyde and modified chitosan was investigated as matrix for hydrophobic interaction chromatography. The influence of temperature, type of salt and its ionic strength on the adsorption of -galactosidase was studied. -Galactosidase was found to bind in presence of high concentration of ammonium sulphate (3 M, w/v) and 90% of the bound enzyme was eluted with decreasing salt concentration in presence of 10% ethylene glycol. Attempt was made to purify -galactosidase from modified chitosan, -galactosidase showed 1.7-fold purification with 43.96% recovery of enzyme activity. The SDS–PAGE analysis of enzyme showed considerable purification and its molecular weight was found to be 63–64 kDa. Unlike other chromatographic matrices, the prepared chitosan beads were used five times. The results showed that purification and recovery of the enzyme did not change even when column size was increased.     

水稻白叶枯病抗性基因Xa23鉴别菌株突变体库的构建及无毒基因突变体的筛选

利用in vivo转座技术构建了白叶枯病抗性基因Xa23鉴别菌株的突变体库,特异性引物PCR扩增和转座子插入位点旁侧序列分析结果表明转座子插入到白叶枯病菌的基因组中。经人工接种鉴定,筛选到4个毒力发生变化的突变体。为进一步克隆Xa23无毒基因提供了条件。     

9F系列海洋真菌代谢产物分离纯化及稻瘟霉活性研究

自帕劳群岛的3株9F系列海洋真菌中分离得到4个化合物,采用MS,NMR等光谱技术,确定结构分别为trans-dehydrocurvularin（1）,terrein（2）,paxilline（3）和citreopyrone（4）,其对稻瘟霉P-2b菌株的最小抑制浓度分别为：10,100,1．56,3．12μg/mL。其中化合物1是首次从海洋真菌中分离得到。