Silicone tube micro extraction: Repeated sampling of benzoxazinoids in the root zone of winter cereals

TY - CONF

T1 - Silicone tube micro extraction

T2 - 8th World Congress of Allelopathy

AU - Reiss, Antje

AU - Fomsgaard, Inge S.

AU - Mathiassen, Solvejg Kopp

AU - Kudsk, Per

PY - 2017/7

Y1 - 2017/7

N2 - Benzoxazinoids are secondary plant metabolites highly abundant in the Poaceae, including the grain crops wheat, triticale and rye. Benzoxazinoids have been shown to be phytotoxic to a range of weed species and suppress the growth of soil fungi, such as Gaeumannomyces graminis, the cause of the take-all disease in cereals. Hence, an improved knowledge on the prevalence and temporal distribution of benzoxazinoids in the root zone is of major interest. In this trial, four cultivars of winter rye, winter triticale and winter wheat were sown at the end of September and mid of October 2015 in the presence and absence of weed. Plants were grown outdoor in boxes (50x34x29) in a roofed area. Silicone tube micro extraction (STME) was used for repeated sampling of compounds in the root zone of the cereals during early growth in spring 2016. In each box, seven meters of tube were placed uniformly in the root zone and compounds were sampled with 100 % MeOH at a speed of 0.1 ml/min and analysed in the multiple reaction mode with an Applied Biosystems 4500 Q Trap LC-MS/MS. Samples contained mostly lipophilic or neutral compounds and it was possible to quantify the content of benzoxazinoids benzoxazolin-2-one (BOA), 2-hydroxy-1,4-benzoxazin-3-one (HBOA), 2-hydroxy-7-methoxy-1,4-benzoxazin-3-one (HMBOA) and 6-methoxy-benzoxazolin-2-one (MBOA) and the phenozaxinones 2-amino-phenoxazin-3-one (APO) and 2-amino-7-methoxy-3H-phenoxazin-3-one (AMPO). Samples taken in April contained more of the microbial degradation products APO and AMPO and had generally higher benzoxazinoid concentrations, compared to samples taken in March. There was no difference between benzoxazinoid concentrations according to sowing date and presence or absence of weeds. In summary, STME is a promising method for repeated sampling of non- glycosylated benzoxazinoids in the root zone of winter cereals.

AB - Benzoxazinoids are secondary plant metabolites highly abundant in the Poaceae, including the grain crops wheat, triticale and rye. Benzoxazinoids have been shown to be phytotoxic to a range of weed species and suppress the growth of soil fungi, such as Gaeumannomyces graminis, the cause of the take-all disease in cereals. Hence, an improved knowledge on the prevalence and temporal distribution of benzoxazinoids in the root zone is of major interest. In this trial, four cultivars of winter rye, winter triticale and winter wheat were sown at the end of September and mid of October 2015 in the presence and absence of weed. Plants were grown outdoor in boxes (50x34x29) in a roofed area. Silicone tube micro extraction (STME) was used for repeated sampling of compounds in the root zone of the cereals during early growth in spring 2016. In each box, seven meters of tube were placed uniformly in the root zone and compounds were sampled with 100 % MeOH at a speed of 0.1 ml/min and analysed in the multiple reaction mode with an Applied Biosystems 4500 Q Trap LC-MS/MS. Samples contained mostly lipophilic or neutral compounds and it was possible to quantify the content of benzoxazinoids benzoxazolin-2-one (BOA), 2-hydroxy-1,4-benzoxazin-3-one (HBOA), 2-hydroxy-7-methoxy-1,4-benzoxazin-3-one (HMBOA) and 6-methoxy-benzoxazolin-2-one (MBOA) and the phenozaxinones 2-amino-phenoxazin-3-one (APO) and 2-amino-7-methoxy-3H-phenoxazin-3-one (AMPO). Samples taken in April contained more of the microbial degradation products APO and AMPO and had generally higher benzoxazinoid concentrations, compared to samples taken in March. There was no difference between benzoxazinoid concentrations according to sowing date and presence or absence of weeds. In summary, STME is a promising method for repeated sampling of non- glycosylated benzoxazinoids in the root zone of winter cereals.

KW - Silicone Tube Microextraction, LC-MS/MS, Triticum aestivum, Triticosecale, Secale cereale, cereals, benzoxazinoids

M3 - Poster

Y2 - 24 July 2017 through 28 July 2017

ER -