title: Benzoxazinoids in rye allelopathy - from discovery to application in sustainable weed control and organic farming.
abstract: The allelopathic potency of rye (Secale cereale L.) is due mainly to the presence of phytotoxic benzoxazinones-compounds whose biosynthesis is developmentally regulated, with the highest accumulation in young tissue and a dependency on cultivar and environmental influences. Benzoxazinones can be released from residues of greenhouse-grown rye at levels between 12 and 20 kg/ha, with lower amounts exuded by living plants. In soil, benzoxazinones are subject to a cascade of transformation reactions, and levels in the range 0.5-5 kg/ha have been reported. Starting with the accumulation of less toxic benzoxazolinones, the transformation reactions in soil primarily lead to the production of phenoxazinones, acetamides, and malonamic acids. These reactions are associated with microbial activity in the soil. In addition to benzoxazinones, benzoxazolin-2(3H)-one (BOA) has been investigated for phytotoxic effects in weeds and crops. Exposure to BOA affects transcriptome, proteome, and metabolome patterns of the seedlings, inhibits germination and growth, and can induce death of sensitive species. Differences in the sensitivity of cultivars and ecotypes are due to different species-dependent strategies that have evolved to cope with BOA. These strategies include the rapid activation of detoxification reactions and extrusion of detoxified compounds. In contrast to sensitive ecotypes, tolerant ecotypes are less affected by exposure to BOA. Like the original compounds BOA and MBOA, all exuded detoxification products are converted to phenoxazinones, which can be degraded by several specialized fungi via the Fenton reaction. Because of their selectivity, specific activity, and presumably limited persistence in the soil, benzoxazinoids or rye residues are suitable means for weed control. In fact, rye is one of the best cool season cover crops and widely used because of its excellent weed suppressive potential. Breeding of benzoxazinoid resistant crops and of rye with high benzoxazinoid contents, as well as a better understanding of the soil persistence of phenoxazinones, of the weed resistance against benzoxazinoids, and of how allelopathic interactions are influenced by cultural practices, would provide the means to include allelopathic rye varieties in organic cropping systems for weed control.
authors: IMBIO Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Karlrobert-Kreiten Str. 13, 53115 Bonn, Germany. ulp509@uni-bonn.de
authors: Margot
authors: M
authors: Schulz
authors: Adriano
authors: A
authors: Marocco
authors: Vincenzo
authors: V
authors: Tabaglio
authors: Francisco A
authors: FA
authors: Macias
authors: Jose M G
authors: JM
authors: Molinillo
mesh_terms: D048588:Benzoxazines / Q000737:chemistry / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D058871:Organic Agriculture / Q000379:methods*; D010675:Pheromones / Q000737:chemistry / Q000378:metabolism*; D012434:Secale / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D058728:Weed Control / Q000379:methods*
chemical_list: D048588:Benzoxazines; D010675:Pheromones; D012987:Soil
references: Phytochemistry. 1999 Mar;50(6):925-30
references: 10385992
references: Phytochemistry. 2008 Nov;69(15):2668-77
references: 18929374
references: Z Naturforsch C J Biosci. 2006 Sep-Oct;61(9-10):670-6
references: 17137112
references: J Chem Ecol. 2005 Aug;31(8):1887-905
references: 16222814
references: J Chem Ecol. 1991 Jan;17(1):9-19
references: 24258430
references: J Chem Ecol. 1987 Apr;13(4):889-906
references: 24302054
references: J Plant Physiol. 2010 Oct 15;167(15):1221-5
references: 20605653
references: J Exp Bot. 2004 Jul;55(402):1587-92
references: 15181106
references: Appl Environ Microbiol. 2003 Oct;69(10):6025-31
references: 14532058
references: J Chem Ecol. 2005 May;31(5):1205-22
references: 16124242
references: Plant Sci. 2011 Feb;180(2):196-203
references: 21421361
references: J Chem Ecol. 2005 Jan;31(1):179-93
references: 15839489
references: J Agric Food Chem. 2006 Feb 22;54(4):1105-10
references: 16478223
references: J Biol Chem. 2005 Jun 10;280(23):21867-81
references: 15824099
references: BMC Evol Biol. 2012 May 11;12:64
references: 22577841
references: Z Naturforsch C J Biosci. 2002 Jul-Aug;57(7-8):660-5
references: 12240993
references: J Agric Food Chem. 2006 Feb 22;54(4):1040-8
references: 16478215
references: J Chem Ecol. 1983 Aug;9(8):1045-57
references: 24407799
references: Appl Environ Microbiol. 2001 Jul;67(7):2973-81
references: 11425710
references: Plant Cell. 2012 Mar;24(3):915-28
references: 22415274
references: Appl Environ Microbiol. 2008 Jan;74(1):136-42
references: 17993551
references: J Plant Physiol. 2011 Jun 15;168(9):863-70
references: 21237530
references: Metabolites. 2011 Dec 15;1(1):64-78
references: 24957244
references: Plant Physiol. 2011 Nov;157(3):985-97
references: 21875895
references: Plant Physiol. 1981 Oct;68(4):941-3
references: 16662030
references: J Appl Microbiol. 2010 May;108(5):1839-49
references: 19912433
references: Plant Cell. 2000 Nov;12(11):2191-200
references: 11090218
references: Plant Signal Behav. 2009 Jul;4(7):580-3
references: 19820349
references: Pest Manag Sci. 2007 Apr;63(4):327-48
references: 17348068
references: Phytochemistry. 2009 Oct-Nov;70(15-16):1645-51
references: 19577780
references: J Chem Ecol. 2013 Feb;39(2):175-85
references: 23385366
references: J Chem Ecol. 2007 Feb;33(2):225-37
references: 17200890
references: Ecotoxicol Environ Saf. 2006 Sep;65(1):1-13
references: 16406583
references: PLoS One. 2012;7(4):e33731
references: 22493673
references: J Biol Chem. 2000 Jun 30;275(26):20002-11
references: 10748038
references: J Agric Food Chem. 2005 Jun 1;53(11):4373-80
references: 15913298
references: Plant J. 2001 Dec;28(6):633-42
references: 11851909
references: Plant Physiol Biochem. 2006 Nov-Dec;44(11-12):819-27
references: 17107811
references: J Agric Food Chem. 2005 Feb 9;53(3):538-48
references: 15686399
references: Phytochemistry. 2004 Apr;65(8):1047-55
references: 15110684
references: Appl Microbiol Biotechnol. 2011 Mar;89(5):1653-63
references: 20972783
references: Pest Manag Sci. 2007 Apr;63(4):308-26
references: 17195966
references: Proc Natl Acad Sci U S A. 2005 Nov 8;102(45):16490-5
references: 16260753
references: PLoS One. 2011;6(11):e26321
references: 22125596
references: Genome. 2005 Oct;48(5):792-801
references: 16391685
references: J Agric Food Chem. 2010 Dec 22;58(24):12710-6
references: 21087039
references: J Chem Ecol. 1990 Feb;16(2):353-64
references: 24263495
references: Plant J. 2011 Dec;68(5):901-11
references: 21838747
references: J Chem Ecol. 2005 Nov;31(11):2689-703
references: 16273435
references: J Chem Ecol. 2013 Feb;39(2):213-31
references: 23385368
references: J Agric Food Chem. 2009 Mar 11;57(5):1677-96
references: 19199602
references: Eur J Biochem. 1969 Mar;8(1):109-12
references: 5781265
references: J Chem Ecol. 1991 Jun;17(6):1037-43
references: 24259166
references: J Chem Ecol. 2010 Feb;36(2):205-9
references: 20143137
references: Proc Natl Acad Sci U S A. 2009 Aug 11;106(32):13213-8
references: 19666594
references: Appl Environ Microbiol. 1998 Jul 1;64(7):2386-91
references: 9647804
references: J Agric Food Chem. 2004 Oct 20;52(21):6402-13
references: 15478999
references: J Chem Ecol. 2012 Jul;38(7):933-46
references: 22614450
references: J Chem Ecol. 2007 Oct;33(10):1885-97
references: 17896139
references: Proc Natl Acad Sci U S A. 2000 Dec 19;97(26):14801-6
references: 11106389
references: Theor Appl Genet. 2003 Nov;107(8):1477-81
references: 12904863
references: J Exp Bot. 2011 Aug;62(13):4533-45
references: 21659663
references: Plant Physiol. 1978 May;61(5):796-802
references: 16660388
references: Appl Environ Microbiol. 2002 Oct;68(10):4863-70
references: 12324332
references: Phytochemistry. 1996 Oct;43(3):551-9
references: 8987579
references: Ecotoxicology. 2006 Feb;15(1):61-72
references: 16344919
references: J Agric Food Chem. 2000 Jul;48(7):2837-42
references: 11032481
references: Phytochemistry. 2001 Nov;58(5):819-25
references: 11672748
references: Planta. 2003 Sep;217(5):776-82
references: 12734755
references: J Agric Food Chem. 2008 Jul 9;56(13):5043-9
references: 18540621
references: J Chem Ecol. 2013 Feb;39(2):142-53
references: 23393005
references: J Nat Prod. 2006 Jan;69(1):34-7
references: 16441064
references: Plant Physiol. 2011 Sep;157(1):317-27
references: 21730199
references: Nat Prod Rep. 2009 Apr;26(4):478-89
references: 19642418
references: Chemosphere. 2005 Sep;61(1):74-84
references: 15876449
references: Phytochemistry. 2003 Feb;62(3):371-6
references: 12620350
references: J Agric Food Chem. 2006 Feb 22;54(4):991-1000
references: 16478208
references: Plant Physiol. 2008 Mar;146(3):1053-63
references: 18192444
references: J Agric Food Chem. 2006 Feb 22;54(4):1064-74
references: 16478218
references: J Chromatogr A. 2005 Feb 25;1066(1-2):249-53
references: 15794579
references: Science. 1997 Aug 1;277(5326):696-9
references: 9235894
references: Int Rev Cytol. 2000;198:319-46
references: 10804466
references: J Chem Ecol. 2004 Mar;30(3):671-89
references: 15139316
references: J Chem Ecol. 1995 Jan;21(1):81-96
references: 24233569
references: Proc Natl Acad Sci U S A. 1998 Oct 27;95(22):12787-92
references: 9788992
references: J Chem Ecol. 1992 Oct;18(10):1683-91
references: 24254712
references: PLoS One. 2012;7(4):e35498
references: 22545111
references: J Chem Ecol. 2012 Jun;38(6):714-27
references: 22585095
references: J Chem Ecol. 1987 Jun;13(6):1481-91
references: 24302247
references: J Agric Food Chem. 2005 Feb 9;53(3):554-61
references: 15686401
references: J Agric Food Chem. 2012 May 9;60(18):4471-9
references: 22500621