Benzoxazinoids - protective secondary metabolites in cereals: Biochemistry and genetic control

Abstract

Benzoxazinoids (1,4-benzoxazin-3(4H)-one derivatives, BXs) are plant secondary metabolites that play a crucial role in plant resistance to insects, fungi, bacteria and nematodes, and in weed suppression during early plant life. These biochemicals are constitutive compounds found in some members of the family Poaceae and have been studied in detail in maize (Zea mays L.), wheat (Triticum aestivum L.) and rye (Secale cereale L.). The most effective allelopathic benzoxazinoids are 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA), classified as hydroxamic acids. Aiming to draw attention to the importance of BXs in plant defence and their potential application in cereal protection, this review summarises the recent findings in genetic control, biochemical pathways, and the mode of action of these secondary metabolites and addresses unresolved questions related to BXs.

Benzoksazinoidi (1,4­benzoksazin­3(4H)­on derivati) su sekundarni metaboliti biljaka koji, u njihovim ranim fazama rasta, igraju važnu ulogu u otpornosti prema štetnim insektima, gljivama, bakterijama i nematodama, i u suzbijanju korova (alelopatiji). Ova biohemijska jedinjenja prisutna su kod nekih članova porodice Poaceae i detaljnije su proučena kod kukuruza (Zea mays L.), pšenice (Triticum aestivum L.) i raži (Secale cereale L.). Najdelotvorniji alelopatski benzoksaziniodi su 2,4-dihidroksi-7-metoksi-2H-1,4-benzoksazin-3(4H)-on (DIMBOA) i 2,4-dihidroksi-1,4-benzoksazin-3-on (DIBOA), koji se klasifikuju kao hidroksamske kiseline. Sa ciljem da ukaže na značaj benzoksazinoida u odbrambenim mehanizmima biljaka i njihovu moguću primenu u zaštiti žitarica, ovaj pregledni rad sažima dosadašnja otrića o genetičkog kontroli, biohemijskim putevima, i načinu delovanja ovih sekundarnih metabolita i ukazuje na nerazjašnjena pitanja koja se odnose na benzoksazinoide.