Absorption and Elimination of the Allelochemical MBOA by Weeds during Seedling Growth

Alberto Oliveros-Bastidas,José M G Molinillo,Francisco A Macias,Nuria Chinchilla

doi:10.3390/agronomy11030471

Alberto Oliveros-Bastidas, José M G Molinillo + Show 2 more

Open Access

https://doi.org/10.3390/agronomy11030471

Copy DOI

Abstract

6-Methoxy-2-benzoxazolinone (MBOA) is an allelochemical that is found in Poaceae and is 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 two weed species, namely Echinochloa crus-galli and Lolium rigidum, and a resistant biotype of Lolium rigidum (SLR31) was studied both qualitatively and quantitatively. The product of metabolism is similar for both weed species. This finding indicates that these weeds probably metabolize xenobiotics by an identical route, since the product detected was the same in both cases. Kinetic studies on the absorption and translocation to the shoot showed differences in these processes depending on the species. The analysis of treated plants, which were subsequently transplanted to a growth medium without xenobiotic compound, showed that the weeds studied are capable of transmitting the previously absorbed compound to the medium by root exudation. The results show that this process is another defense mechanism of plants facing external threats.

Highlights

The MBOA quantities detected in target seedlings can be attributed solely to MBOA absorption
The results indicate that the seedlings show signs of recovery if they are transplanted into a growth medium without a test compound
The results show that two species can absorb and translocate to the shoot MBOA occurring in the growth medium

Summary

Introduction

Cyclic hydroxamic acids and related benzoxazolinone compounds are an important group of allelochemicals in Gramineous plants They are specialized metabolites and an important element of the defense mechanism against biotic and abiotic stresses in plant species predominantly belonging to the Poaceae [1,2]. These compounds are found in corn, rye and wheat but not in rice, barley or oats [3]. The maximum recorded level of hydroxamic acids in cultivated wheat is 11 mmol/kg fresh weight [4] Root exudation of these compounds has been observed [5]. Very few studies have concerned the quantification of the interactions between allelochemicals and plants at the molecular level

Objectives

Results

Discussion

Conclusion