Absorción y eliminación de Aleloquímicos MBOA por Malezas Durante el Crecimiento de Plántulas

Abstract

6-Methoxy-2-benzoxazolinone (MBOA) is an allelochemical found in Poaceae, generally associated with monocotyledon species. This compound is formed from the glycosylated form of 2, 4-dihydroxy-2H-1, 4-benzoxazin-3 (4H)-one (Gly-DIMBOA) by a two-stage degradation process. The MBOA detoxification capacity of three weed species Echinochloa crus-galli, andLolium rigidum, including a resistant biotype of Lolium rigidum (SLR31) was studied bothqualitatively and quantitatively. For all three species, the product of metabolism is similar. This should indicate that all weeds metabolize xenobiotics through an identical route, since the product detected is the same. Kinetic studies of absorption and translocation to the shoot, show differences in these processes depending on the species. The analysis of treated plants, later transplanted to a growth medium without xenobiotic, showed that the weeds studied are capable of transmitting to the medium the previously absorbed compound, by root exudate. This evidence shows that this process is another route of defense of plants facing external stressors and is important to explain the differential behavior of weeds in field studies.