Issue |
Agron. Sustain. Dev.
Volume 29, Number 2, April-June 2009
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Page(s) | 313 - 319 | |
DOI | https://doi.org/10.1051/agro:2008048 | |
Published online | 18 October 2008 |
DOI: 10.1051/agro:2008048
Festuca arundinacea grass and herbicide safeners to prevent herbicide pollution
Luciano Scarponi, Daniele Del Buono, Elisa Quagliarini and Roberto D'AmatoDipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Perugia, Borgo XX Giugno 72, 06121 Perugia, Italy
Accepted 30 July 2008; published online 18 October 2008
Abstract - Buffer strips are uncultivated zones left along the boundaries of crops.
Buffer strips are used to eliminate or reduce the environmental impact of
herbicides. As the efficiency of buffer strips is improved by the presence
of non-crop vegetation, we studied the possible role of growing the
perennial grass Festuca arundinacea. We investigated the activity in festuca
of glutathione S-transferase (GST), which is an enzyme very active in metabolising
herbicides. Our results evidence GST activity, which is enhanced by the
following compounds: benoxacor, cloquintocet-mexyl, fenchlorazol-ethyl,
fenclorim, fluxofenim and oxabetrinil. These synthetic compounds are named
herbicide safeners because they protect crop plants against injury from some
herbicides without reducing the action of herbicides against the target
weeds. The increases in GST activity were found to be concomitant with
changes in V and K
, that are kinetic constants related
directly to the enzyme concentration in the protein “pull” and inversely
to the substrate–enzyme affinity, respectively. In particular, V
increase with
K
decrease was observed in response to benoxacor, V
increases
were found in response to fenchlorazol-ethyl, fenclorim, fluxofenim and
oxabetrinil, and K
decrease was observed in response to
cloquintocet-mexyl. The GST activity was also found to be enhanced by the
safeners when it was tested toward the herbicides terbuthylazine and
butachlor as substrates. In particular, the increases in GST toward
terbuthylazine ranged in the following decreasing order: 154.6%,
91.7%, 89.2%, 88.3%, 82.5% and 30.8% in response to
fluxofenim, fenchlorazol-ethyl, fenclorim, oxabetrinil, benoxacor and
cloquintocet-mexyl, respectively. The increases in GST toward butachlor
ranged in the following decreasing order: 77.0%, 71.2% 59.0%,
41.0% and 33.1% in response to oxabetrinil, benoxacor, fenclorim,
fluxofenim and fenchlorazol-ethyl, respectively. A further test, performed
to evaluate the relevance of the above effects on a macro-scale level,
evidenced 10.1% and 32.7% increased amounts of metabolised
terbuthylazine and butachlor, respectively, in response to the addition of
benoxacor safener to the herbicide treatments. These results indicate that
herbicide diffusion following the runoff of surface waters can be prevented
or significantly reduced by vegetating buffer strips with festuca and by the
combination of herbicide and a suitable safener.
Key words: Festuca arundinacea / glutathione S-transferase / terbuthylazine / butachlor / safeners / detoxification / buffer strips
Corresponding author: scarponi@unipg.it
© INRA, EDP Sciences 2008