Dynamic analysis on weeds inhibition and phenolic acids of allelopathic rice in field test

Abstract

ABSTRACT Weed suppression of allelopathic rice PI312777 (PI) and non-allelopathic rice Lemont (LE) at 3-, 5-, and 7-leaf stages were studied in field test. The results showed that inhibitory effect of rice rhizosphere soil (IR1), the soil aqueous extracts (IR2), and the mixture of phenolic acids of the soil extracts (IR3) were IR1 > IR2 > IR3. The same trend was observed in the content of total phenols (Ctp) and the phenolic acids (Cpa) in the soil aqueous extract. The qRT-PCR results showed that six genes related to biosynthesis of phenolic acids in rice leaves and roots of PI were up-regulated and the up-regulated multiplies were increased as leaf stage increased. However, four genes were up-regulated and two genes were down-regulated in rice leaves and roots of LE. The regulated multiplies were smaller in LE than that in PI. The correlation analysis showed that IR1, IR2, IR3, Ctp, and Cpa were positively correlated. There results indicated that rice allelopathic potential was enhanced in response of paddy weeds, which accompanied by up-regulation of genes in rice leaves and roots related to metabolism pathway of phenolic compounds and increase of phenolic allelochemicals in rice rhizosphere soil.