Mapping the sirodesmin PL biosynthetic pathway — A remarkable intrinsic steric deuterium isotope effect on a 1H NMR chemical shift determines β-proton exchange in tyrosine

2009 ◽  
Vol 87 (4) ◽  
pp. 556-562 ◽  
Author(s):  
M. Soledade C. Pedras ◽  
Yang Yu
Keyword(s):  
Biosynthetic Pathway ◽  
Leptosphaeria Maculans ◽  
Proton Exchange ◽  
Blackleg Disease ◽  
Deuterium Isotope Effect ◽  
Phoma Lingam ◽  
Spectroscopic Analyses ◽  
Fungal Plant Pathogen ◽  
C Nmr ◽  
1H Nmr Chemical Shift

Sirodesmin PL is both an antibiotic and a phytotoxin produced by a fungal plant pathogen ( Leptosphaeria maculans, asexual stage Phoma lingam ) that causes blackleg disease on crucifers. To determine potential biosynthetic precursors of sirodesmin PL, deuterated compounds were synthesized and incubated with cultures of L. maculans. Incorporations of deuterium into sirodesmin PL (7) and its precursor phomamide (4) were determined using 1H and 13C NMR spectroscopy, LC-HRMS-ESI and HRMS-EI spectrometry. Spectroscopic analyses established that [3,3-2H2]l-tyrosine (1a), [3,3-2H2]O-prenyl-l-tyrosine (9a), [3,3,5′,5′,5′-2H5]O-prenyl-l-tyrosine (9b), and [5,5-2H2]phomamide (4a) were incorporated efficiently into sirodesmin PL (7). Interestingly, an unexpected “twist” revealed that one of the β-deuteria (pro-R) of [3,3-2H2]l-tyrosine (1a) was exchanged stereospecifically before incorporation into sirodesmin PL (7). As well, our studies revealed that O-prenyl-l-tyrosine is likely to be the first committed precursor en route to sirodesmin PL (7).

scholarly journals Absence of isolation by distance patterns at the regional scale in the fungal plant pathogen Leptosphaeria maculans

2011 ◽  
Vol 115 (7) ◽  
pp. 649-659 ◽  
Author(s):  
Renaud Travadon ◽  
Ivan Sache ◽  
Cyril Dutech ◽  
Anna Stachowiak ◽  
Bruno Marquer ◽  
...  
Keyword(s):  
Plant Pathogen ◽  
Isolation By Distance ◽  
Regional Scale ◽  
Leptosphaeria Maculans ◽  
Fungal Plant Pathogen

Mapping genes for resistance to Leptosphaeria maculans in Brassica juncea

Genome ◽  
2006 ◽  
Vol 49 (1) ◽  
pp. 30-41 ◽  
Author(s):  
J A Christianson ◽  
S R Rimmer ◽  
A G Good ◽  
D J Lydiate
Keyword(s):  
Linkage Group ◽  
Brassica Juncea ◽  
Fragment Length Polymorphism ◽  
Leptosphaeria Maculans ◽  
Recessive Gene ◽  
Brassica Species ◽  
Blackleg Disease ◽  
Recessive Resistance ◽  
B Genome ◽  
Restriction Fragment Length

Blackleg disease of crucifers, caused by the fungus Leptosphaeria maculans, is a major concern to oilseed rape producers worldwide. Brassica species containing the B genome have high levels of resistance to blackleg. Brassica juncea F2 and first-backcross (B1) populations segregating for resistance to a PG2 isolate of L. maculans were created. Segregation for resistance to L. maculans in these populations suggested that resistance was controlled by two independent genes, one dominant and one recessive in nature. A map of the B. juncea genome was constructed using segregation in the F2 population of a combination of restriction fragment length polymorphism (RFLP) and microsatel lite markers. The B. juncea map consisted of 325 loci and was aligned with previous maps of the Brassica A and B genomes. The gene controlling dominant resistance to L. maculans was positioned on linkage group J13 based on segregation for resistance in the F2 population. This position was confirmed in the B1 population in which the resistance gene was definitively mapped in the interval flanked by pN199RV and sB31143F. The provisional location of the recessive gene controlling resistance to L. maculans on linkage group J18 was identified using a subset of informative F2 individuals.Key words: blackleg, B genome, phoma, recessive resistance.

scholarly journals Limitations of transcriptome-based prediction of pathogenicity genes in the plant pathogen Leptosphaeria maculans

2019 ◽  
Vol 366 (7) ◽  
Author(s):  
Andrew S Urquhart ◽  
Alexander Idnurm
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Leptosphaeria Maculans ◽  
Simple Expression ◽  
Gene Transcript ◽  
Blackleg Disease ◽  
Fungal Pathogenicity ◽  
Transcript Levels ◽  
Oilseed Crops ◽  
High Gene

ABSTRACT Identification of pathogenicity determinants in Leptosphaeria maculans, a major cause of disease of oilseed crops, has been a focus of research for many years. A wealth of gene expression information from RNA sequencing promises to illuminate the mechanisms by which the fungus is able to cause blackleg disease. However, to date, no studies have tested the hypothesis that high gene transcript levels during infection correlate with importance to disease progression. In this study, we use CRISPR-Cas9 to disrupt 11 genes that are highly expressed during the early stages of disease and show that none of these genes are crucial for fungal pathogenicity on Brassica napus. This finding suggests that in order to understand the pathogenicity of this fungus more sophisticated techniques than simple expression analysis will need to be employed.

scholarly journals Inheritance Pattern and Molecular Markers for Resistance to Blackleg Disease in Cabbage

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 583
Author(s):  
Mostari Jahan Ferdous ◽  
Mohammad Rashed Hossain ◽  
Jong-In Park ◽  
Arif Hasan Khan Robin ◽  
Denison Michael Immanuel Jesse ◽  
...  
Keyword(s):  
Molecular Markers ◽  
High Resolution Melting ◽  
Leptosphaeria Maculans ◽  
Inbred Lines ◽  
Indel Marker ◽  
Detection Accuracy ◽  
Nucleotide Polymorphisms ◽  
Blackleg Disease ◽  
Marker Assisted Breeding ◽  
Single Nucleotide

The inheritance and causal loci for resistance to blackleg, a devastating disease of Brassicaceous crops, are yet to be known in cabbage (Brassica oleracea L.). Here, we report the pattern of inheritance and linked molecular marker for this trait. A segregating BC1 population consisting of 253 plants was raised from resistant and susceptible parents, L29 (♀) and L16 (♂), respectively. Cotyledon resistance bioassay of BC1 population, measured based on a scale of 0–9 at 12 days after inoculation with Leptosphaeria maculans isolate 03–02 s, revealed the segregation of resistance and ratio, indicative of dominant monogenic control of the trait. Investigation of potential polymorphism in the previously identified differentially expressed genes within the collinear region of ‘B. napus blackleg resistant loci Rlm1′ in B. oleracea identified two insertion/deletion (InDel) mutations in the intron and numerous single nucleotide polymorphisms (SNPs) throughout the LRR-RLK gene Bol040029, of which six SNPs in the first exon caused the loss of two LRR domains in the susceptible line. An InDel marker, BLR-C-InDel based on the InDel mutations, and a high resolution melting (HRM) marker, BLR-C-2808 based on the SNP C2808T in the second exon were developed, which predicated the resistance status of the BC1 population with 80.24%, and of 24 commercial inbred lines with 100% detection accuracy. This is the first report of inheritance and molecular markers linked with blackleg resistance in cabbage. This study will enhance our understanding of the trait, and will be helpful in marker assisted breeding aiming at developing resistant cabbage varieties.

scholarly journals Flavonoids from Curcuma longa Leaves and their NMR Assignments

2015 ◽  
Vol 10 (1) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Chia-Ling Jiang ◽  
Sheng-Fa Tsai ◽  
Shoei-Sheng Lee
Keyword(s):  
Nmr Assignments ◽  
Soluble Fraction ◽  
Curcuma Longa ◽  
2D Nmr ◽  
Etoh Extract ◽  
Spectroscopic Analyses ◽  
Nmr Data ◽  
The Common ◽  
Reported Data ◽  
C Nmr

Chemical investigation of the n-BuOH-soluble fraction of the EtOH extract of the aerial part of Curcuma longa led to the isolation of 11 flavonol glycosides and one dihydroflavonol glucoside (1) via chromatography over Sephadex LH-20 and Lobar RP-18 columns. Although they are known, the 1H and 13C NMR data recorded in CD3OD rather than the common DMSO- d6 are doubly checked via extensive 2D NMR spectroscopic analyses, leading to some revisions of the reported data, especially for the glycon part.

Prevalence of blackleg (Leptosphaeria maculans) on canola (Brassica napus) in Western Australia

2001 ◽  
Vol 41 (1) ◽  
pp. 71 ◽  
Author(s):  
R. K. Khangura ◽  
M. J. Barbetti
Keyword(s):  
Western Australia ◽  
Disease Incidence ◽  
Leptosphaeria Maculans ◽  
Sowing Date ◽  
Blackleg Disease ◽  
The Mean ◽  
Seed Yields ◽  
Blackleg Fungus ◽  
Western Australian

Canola crops were monitored throughout the Western Australian wheatbelt during 1996–99 to determine the incidence and severity of crown cankers caused by the blackleg fungus (Leptosphaeria maculans). All crops surveyed had blackleg. The incidence of crown canker was 48–100%, 15–100%, 9–94% and 48–100% during 1996, 1997, 1998 and 1999, respectively. The mean incidence of crown cankers statewide was 85, 63, 55 and 85% in 1996, 1997, 1998 and 1999, respectively. The severity of crown canker (expressed as percentage disease index) ranged between 30 and 96%, 3 and 94%, 5 and 78% and 21 and 96% during 1996, 1997, 1998 and 1999, respectively. These high levels of blackleg can possibly be attributed to the accumulation of large amounts of infested canola residues. In 1999, there were effects of variety, application of the fungicide Impact, distance to last year’s canola residues and rainfall on the incidence and severity of blackleg. However, there were no effects of sowing date or region on the disease incidence or severity once the other factor effects listed above had been considered. In 1995, an additional survey of 19 sites in the central wheatbelt of Western Australia assessed the survival of the blackleg fungus on residues from crops grown in 1992–94. The residues at all sites carried blackleg. However, the extent of infection at any particular site varied from 12 to 100% of stems with the percentage of stems carrying pseudothecia containing ascospores varying between 7 and 96%. The high levels of blackleg disease found in commercial crops are indicative of significant losses in seed yields, making it imperative that management of blackleg be improved if canola is to remain a viable long-term cropping option in Western Australia.

scholarly journals Genome-Wide Identification and Analysis of VQ Motif-containing Gene Family in Brassica napus and Functional Characterization of BnMKS1 in Response to Leptosphaeria maculans

2020 ◽  
Author(s):  
Zhongwei Zou ◽  
Fei Liu ◽  
Shuanglong Huang ◽  
DILANTHA GERARD FERNANDO
Keyword(s):  
Brassica Napus ◽  
Gene Family ◽  
Functional Characterization ◽  
Leptosphaeria Maculans ◽  
Defense Responses ◽  
Marker Genes ◽  
Blackleg Disease ◽  
Genome Wide ◽  
A Genome

Proteins containing Valine-glutamine (VQ) motifs play important roles in plant growth and development, as well as in defense responses to both abiotic and biotic stresses. Blackleg disease, which is caused by Leptosphaeria maculans, is the most important disease in canola (Brassica napus L.) worldwide. H; however, the identification of B. napus VQs and their functions in response to blackleg disease have not yet been reported. In this study, we conducted a genome genome-wide identification and characterization of the VQ gene family in B. napus, including chromosome location, phylogenetic relations, gene structure, motif domain, synteny analysis, and cis-elements categorization of their promoter regions. To understand B. napus VQ gene function in response to blackleg disease, we overexpressed BnVQ7 (BnaA01g36880D, also known as the mitogen-activated protein kinase4 substrate1 (MKS1) gene) in a blackleg-susceptible canola variety Westar. Overexpression The overexpression of BnMKS1 in canola did not improve its resistance to blackleg disease at the seedling stage. H; however, transgenic canola plants overexpressing BnMKS1 displayed an enhanced resistance to L. maculans infection at the adult plant stage. Expression levels of downstream and defense marker genes in cotyledons increased significantly at the necrotrophic stage of L. maculans infection in the overexpression line of BnMKS1, suggesting that the SA salicylic acid (SA)- and jasmonic acid (JA )-mediated signaling pathways were both involved in the defense responses. Together, these results suggest that BnMKS1 might play an important role in the defense against L. maculans.

scholarly journals The Study of the Reaction of Pectin-Ag(0) Nanocomposites Formation

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Nadezhda Viktorovna Ivanova ◽  
Natalya Nikolaevna Trofimova ◽  
Lydmila Alexandrovna Es'kova ◽  
Vasilyi Anatolievich Babkin
Keyword(s):  
Aqueous Solutions ◽  
Larix Sibirica ◽  
Side Chains ◽  
Chemical Transformations ◽  
Reaction Conditions ◽  
Rhamnogalacturonan I ◽  
Spectroscopic Analyses ◽  
Furanose Form ◽  
Branched Structure ◽  
C Nmr

Pectin polysaccharides (PSs) were isolated from a bark of Larix sibirica Ledeb. Structure of PS fragments determined by chemical transformations, chromatography, and spectroscopic analyses was found to be a linear galacturonane comprising 1,4-linked α-D-GalpA residues and a rhamnogalacturonan I (RG-I). The fifth part of galacturonane residues was methyl esterified at at C-2 and/or C-3 and C-6 atoms. Some of RG-I side chains were identified as arabinogalactan subunits with highly branched structure consisting of linear backbone with3,6)-β-D-Galp-(1residues, substituted at C-6 by neutral side chains. This side chains contained2,5)-α-L-Araf-(1and3,5)-α-L-Araf-(1residues and terminal arabinose in the pyranose and furanose form. It was found that “pectin-Ag(0)” nanobiocomposites were formed via the interaction between PS aqueous solutions and silver nitrate, with PS playing both reducing and stabilizing functions. It was shown that the content of Ag(0) particles in “pectin-Ag(0)” depended on the reaction conditions and can range from 0.1 to 72 %, the size of Ag(0) particles being 3–27 nm. Using 13C NMR technique, it was revealed that PS underwent destructive changes and they they were more considerable, more than the lot of Ag(I) that was inputed into the reactionary medium.

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