Near-isogenic lines for measuring phenotypic effects of DIMBOA-Glc methyltransferase activity in maize.
Three O-methyltransferases (BX10a, b, c) catalyze the conversion of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIM BOA-Glc) to 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside (HDMBOA -Glc) in maize (Zea mays). Variation in benzoxazinoid accumulation and resistance to Rhopalosiphum maidis (corn leaf aphid) was attributed to a natural CACTA family transposon insertion that inactivates Bx10c. Whereas maize inbred line B73 has this transposon insertion, line CM L277 does not. To characterize the phenotypic effects of DIM BOA-Glc methyltransferase activity, we created near-isogenic lines derived from B73 and CM L277 that do or do not contain the transposon insertion. Bx10c inactivation causes high DIM BOA -Glc, low HDMBOA-Glc, and decreased aphid reproduction relative to near-isogenic lines that have a functional Bx10c gene. These results confirm the importance of this locus in maize aphid resistance. The availability of Bx10c near-isogenic lines will facilitate further research on the function of different benzoxazinoids and DIM BOA-Glc methyltransferase activity in maize defense against herbivores and pathogens.
Valeria
V
Mijares
Lisa N
LN
Meihls
Georg
G
Jander
Vered
V
Tzin
D000818:Animals; D001042:Aphids / Q000472:pathogenicity*; D008780:Methyltransferases / Q000378:metabolism*; D012098:Reproduction / Q000502:physiology*; D003313:Zea mays / Q000201:enzymology* / Q000469:parasitology*
D008780:Methyltransferases