Gembloux Agro-Bio Tech (GxABT)
Gembloux Agro-Bio Tech (GxABT)

Contribution on the study of allelopathic interactions between Amaranthus retroflexus L. and Secale cereale L.

Berdy, Jeremy ULiège
Promotor(s) : Fauconnier, Marie-Laure ULiège ; Lheureux, Laura ULiège
Date of defense : 6-Apr-2023 • Permalink :
Title : Contribution on the study of allelopathic interactions between Amaranthus retroflexus L. and Secale cereale L.
Translated title : [fr] Contribution à l'étude des interactions allélopathique entre Amaranthus retroflexus L et Secale cereale L.
Author : Berdy, Jeremy ULiège
Date of defense  : 6-Apr-2023
Advisor(s) : Fauconnier, Marie-Laure ULiège
Lheureux, Laura ULiège
Committee's member(s) : Purcaro, Giorgia ULiège
Gfeller, Aurélie 
mustaq, wasseem 
De Clerck, Caroline ULiège
Delaplace, Pierre ULiège
Language : English
Number of pages : 76
Keywords : [en] Redroot pigweed, Rye, Allelopathy, Root volatile organic compounds, Phenomics
Discipline(s) : Life sciences > Multidisciplinary, general & others
Research unit : Laboratoire de chimie des molécules naturels, Gembloux Agro-Biotech
Institution(s) : Université de Liège, Liège, Belgique
Degree: Master en bioingénieur : chimie et bioindustries, à finalité spécialisée
Faculty: Master thesis of the Gembloux Agro-Bio Tech (GxABT)


[en] Amaranthus retroflexus L., commonly known as redroot pigweed, is a well-known summer weed that
poses significant challenges to multiple cropping ecosystems. Historically, intensive use of herbicides
has been the primary method of weed control since the Green Revolution. However, this approach is
becoming less effective due to the increasing adaptation and resistance of weed species to herbicides.
Additionally, the negative side effects associated with herbicide use emphasize the need for the
implementation of sustainable weed management practices. Considering the above considerations, the
adoption of rye (Secale cereale L.), which is one of the most potent allelopathic crops, holds significant
importance. The problem addressed in this study is the lack of knowledge concerning the causes and
effects of the interactions between those two plant species.
The focal plant in this case was rye. Two populations were grown in controlled conditions and in
hydroponics. One group serving as a control, and the other group being subjected to an aqueous extract
of redroot pigweed. Different potential effects of this extract were monitored during 9-day long
development of the rye seedlings.
Below ground interaction between the focal plant and other organisms is suspected to be strongly
modulated by volatile organic compounds (VOCs). To elucidate this mystery, the volatilome inside the
hydroponic system was determined using a custom-made growth apparatus that would allow the direct
pumping of root volatiles using dynamic headspace sampling and followed by GC-MS analysis of the
captured compounds.
The investigation of phenotypical variables in the study included gravimetric analysis of biomass
allocation and root scanning to assess root architecture. These variables served as indicators of potential
inhibition, stimulation, or alteration of rye's developmental pattern.
Lastly, rye is specialized in the production of allelochemicals called benzoxazinoids. Their production,
accumulation and release are strongly dependent on environmental stimuli. The inducible production of
the root treatment using metabolites belonging to redroot pigweed was investigated.
Results of the present experimentations show that the aqueous extract of redroot pigweed is affecting
the growth pattern of rye roots. The promotion of lateral root elongation was already observed after six
days of treatment. Perturbation of the auxin-ethylene growth regulation system is suspected. The overall
allocation of biomass from root to shoot does not show significant variations when comparing the two
Regarding the analysis of the volatilome, potential constitutive signals were identified in rye roots, both
in control and treated groups. Furthermore, treatment appeared to stimulate the emission of certain
volatile organic compounds (VOCs) while suppressing others. Some of the detected VOCs were
attributed to emission by plant growth-promoting rhizobacteria rather than the roots themselves.
Additionally, some of these compounds have been found to possess toxic activity, thereby inhibiting
potential pathogenic organisms within the rhizosphere. This underscores the fact that rye employs not
only benzoxazinoids or exudates, but also VOCs, to mediate subterranean interactions.
In the context of treatment with an extract, no discernible variation in the benzoxazinoid content of rye
shoot was detected. Despite its susceptibility to external stimuli, the priming of the defense mechanisms
of rye shoots were not observed.



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  • Berdy, Jeremy ULiège Université de Liège > Gembloux Agro-Bio Tech


Committee's member(s)

  • Purcaro, Giorgia ULiège Université de Liège - ULiège > Département GxABT > Chimie des agro-biosystèmes
    ORBi View his publications on ORBi
  • Gfeller, Aurélie Agroscope > Malherbologie
  • mustaq, wasseem Uliege > Gxabt > LCMN
  • De Clerck, Caroline ULiège Université de Liège - ULiège > Département GxABT > Plant Sciences
    ORBi View his publications on ORBi
  • Delaplace, Pierre ULiège Université de Liège - ULiège > Département GxABT > Plant Sciences
    ORBi View his publications on ORBi
  • Total number of views 17
  • Total number of downloads 84

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