Institute of Tropical and Subtropical Ecology, South China Agricultural University, Guangzhou, 510642, China.
*Correspondence Author: E-mail: wangjw@scau.edu.cn
The allelopathic effects of aqueous extracts from leaves of maize (Zea mays L.) on barnyardgrass (Echinochloa crusgalli L.) were tested to induce effects of methyl jasmonate (MeJA) on the content of hydroxamic and phenolic acids and the expression of related genes. The results showed that maize treated with MeJA induced the accumulation of DIMBOA and its derivative, and phenolic acids in its leaves and roots. The expression patterns of several defence-related genes were analyzed in MeJA treated maize by using RT-PCR. The expression of AOC, PAL and BX9 genes, which help in the biosynthesis of jasmonates, phenolic acids and DIMBOA-glucoside, were induced in maize leaves and/or roots treated with MeJA for 48 h. The highest transcript level of BX1, which is the first gene for DIMBOA biosynthesis, was observed in leaves after 3 h of MeJA treatment. However, the expression of the BX1 was not detected either in shoot or in root even after 48 h of MeJA treatment. Further studies showed that aqueous extracts of MeJA-treated maize leaf were more inhibitory to the root length of barnyardgrass compared to untreated control.
Allelopathic activity, DIMBOA, Echinochloa crusgalli, maize, methyl jasmonate, phenolic acid
