Journal: Frontiers in Plant Science

Article Title: One Pathway Is Not Enough: The Cabbage Stem Flea Beetle Psylliodes chrysocephala Uses Multiple Strategies to Overcome the Glucosinolate-Myrosinase Defense in Its Host Plants

doi: 10.3389/fpls.2018.01754

Figure Lengend Snippet: Metabolic fate of ingested 4MSOB GLS in P. chrysocephala adults.

Article Snippet: 4MSOB-amine, 4MSOB-ITC-glutathione (GSH), 4MSOB-ITC-cysteine (Cys), and 4MSOB-ITC- N -acetylcysteine were purchased from Santa Cruz Biotechnology (Dallas, USA).

Techniques:

Journal: Frontiers in Plant Science

Article Title: One Pathway Is Not Enough: The Cabbage Stem Flea Beetle Psylliodes chrysocephala Uses Multiple Strategies to Overcome the Glucosinolate-Myrosinase Defense in Its Host Plants

doi: 10.3389/fpls.2018.01754

Figure Lengend Snippet: Amount of intact 4-methylsulfinylbutyl (4MSOB) GLS in P. chrysocephala adults after feeding on the myrosinase-deficient mutant ( tgg1 × tgg2 ) or wild-type A. thaliana Col-0. Two newly emerged adults were allowed to feed on a detached leaf from a five-week old mutant or wild-type plant for 24 h, and subsequently on a detached leaf of the A. thaliana myb28 × myb29 mutant devoid of aliphatic GLS for 20 h. Extracted GLS from leaves and adults were analyzed by HPLC-UV. The 4MSOB GLS concentration per mg fresh weight in adults was determined and expressed relative to the 4MSOB GLS concentration in the corresponding leaf which was set to 100% ( N = 24). *** P < 0.001.

Article Snippet: 4MSOB-amine, 4MSOB-ITC-glutathione (GSH), 4MSOB-ITC-cysteine (Cys), and 4MSOB-ITC- N -acetylcysteine were purchased from Santa Cruz Biotechnology (Dallas, USA).

Techniques: Mutagenesis, Concentration Assay

Journal: Frontiers in Plant Science

Article Title: One Pathway Is Not Enough: The Cabbage Stem Flea Beetle Psylliodes chrysocephala Uses Multiple Strategies to Overcome the Glucosinolate-Myrosinase Defense in Its Host Plants

doi: 10.3389/fpls.2018.01754

Figure Lengend Snippet: Metabolic fate of ingested 4MSOB GLS in P. chrysocephala adults. Ingested 4MSOB GLS is partially sequestered and additionally detoxified by desulfation. A fraction of ingested 4MSOB GLS is activated by the plant myrosinase to 4MSOB isothiocyanate (ITC) and the corresponding nitrile (4MSOB-cyanide). 4MSOB-ITC is detoxified by conjugation with glutathione (GSH). The ITC-GSH conjugate is metabolized via the mercapturic acid pathway to several cyclic ITC-Cys conjugates, i.e., 2-(4-(methylsulfinyl)butylamino)-4,5-dihydrothiazole-carboxylic acid (4MSOB-ITC-Cyclic-Cys conjugate A), 4-amino-3- (4-(methylsulfinyl)butyl)-2- thioxothiazolidine-4-carboxylic acid (4MSOB-ITC-Cyclic-Cys conjugate B, compound 2), and 4-hydroxy-3-(4-(methylsulfinyl)butyl)-2-thioxothiazolidine-4-carboxylic acid (4MSOB-ITC-Cyclic-Cys conjugate C, compound 3). Additionally, 4MSOB-amine and 4MSOB-acetamide (compound 1) were detected. Proposed metabolic steps are indicated with dashed arrows.

Article Snippet: 4MSOB-amine, 4MSOB-ITC-glutathione (GSH), 4MSOB-ITC-cysteine (Cys), and 4MSOB-ITC- N -acetylcysteine were purchased from Santa Cruz Biotechnology (Dallas, USA).

Techniques: Conjugation Assay

Journal: Frontiers in Plant Science

Article Title: One Pathway Is Not Enough: The Cabbage Stem Flea Beetle Psylliodes chrysocephala Uses Multiple Strategies to Overcome the Glucosinolate-Myrosinase Defense in Its Host Plants

doi: 10.3389/fpls.2018.01754

Figure Lengend Snippet: Metabolism of 4MSOB-amine in P. chrysocephala . Feces of adults which ingested 4MSOB-amine and subsequently fed on a detached leaf of the A. thaliana myb28 × myb29 mutant devoid of aliphatic GLS for 20 h were extracted with 0.1% (v/v) formic acid (pH 3). Feces extracts were analyzed by HPLC-MS (ion trap) in comparison to the 4MSOB-amine reference. Extracted ion chromatograms of 4MSOB-amine ( m/z 136; A,C ) and 4MSOB-acetamide ( m/z 178; B , D ) in positive ionization mode [M+H] + are shown. A low amount of 4MSOB-acetamide was detected in the 4MSOB-amine reference (peak labeled with an asterisk).

Article Snippet: 4MSOB-amine, 4MSOB-ITC-glutathione (GSH), 4MSOB-ITC-cysteine (Cys), and 4MSOB-ITC- N -acetylcysteine were purchased from Santa Cruz Biotechnology (Dallas, USA).

Techniques: Mutagenesis, Comparison, Labeling

Journal: Frontiers in Plant Science

Article Title: One Pathway Is Not Enough: The Cabbage Stem Flea Beetle Psylliodes chrysocephala Uses Multiple Strategies to Overcome the Glucosinolate-Myrosinase Defense in Its Host Plants

doi: 10.3389/fpls.2018.01754

Figure Lengend Snippet: Metabolism of 4MSOB-ITC- 13 C 3 15 N-Cys in P. chrysocephala . Feces of adults which ingested 4MSOB-ITC- 13 C 3 15 N-Cys conjugate and subsequently fed on a detached leaf of the A. thaliana myb28 × myb29 mutant devoid of aliphatic GLS for 20 h were extracted with 0.1% (v/v) formic acid (pH 3). Feces extracts were analyzed by HPLC-MS (ion trap) in comparison to the 4MSOB-ITC- 13 C 3 15 N-Cys conjugate reference. Extracted ion chromatograms of 4MSOB-ITC- 13 C 15 N-Cys conjugate ( m/z 301; A,C ) and the labeled 4-amino-3-(4-(methylsulfinyl)butyl)-2-thioxothiazolidine-4-carboxylic acid (4MSOB-ITC-Cyclic-Cys conjugate B), and 4-hydroxy-3-(4-(methylsulfinyl)butyl)-2-thioxothiazolidine-4-carboxylic acid (4MSOB-ITC-Cyclic-Cys conjugate C) ( m/z 299; B,D ) in negative ionization mode [M–H] − are shown. 4MSOB-ITC- 13 C 3 15 N-Cys conjugate and 4MSOB-ITC-Cyclic-Cys conjugate B have the same retention time under the applied HPLC conditions. The peaks marked with “+” correspond to the 34 S-isotopologues of the labeled 4MSOB-ITC-Cyclic-Cys conjugates B and C.

Article Snippet: 4MSOB-amine, 4MSOB-ITC-glutathione (GSH), 4MSOB-ITC-cysteine (Cys), and 4MSOB-ITC- N -acetylcysteine were purchased from Santa Cruz Biotechnology (Dallas, USA).

Techniques: Mutagenesis, Comparison, Labeling