| Description |
Biotic and abiotic cues can trigger priming in plants, which enables plants to respond to subsequent challenge with stronger and/or faster responses. It is well known that herbivory activates defense-related responses in systemic leaves. However, little is known about whether insect feeding activates priming in systemic leaves. Quantification of phytohormone jasmonic acid (JA) and defense metabolites benzoxazinoids (Bxs), insect bioassay, genetic and transcriptome analysis were performed to study whether and how herbivory induces priming in maize systemic leaves. Actual and simulated Mythimna separata herbivory in maize local leaves primed the systemic leaves for enhanced accumulation of JA and Bxs and increased resistance to M. separata. Activation of priming in maize systemic leaves depends on both the duration of simulated herbivory and perception of M. separata OS in the local leaves, and genetic analysis indicated that JA and Bxs are required for the primed defenses in the systemic leaves. Consistently, in response to simulated herbivory, compared with non-primed systemic leaves, the primed systemic leaves exhibited a large number of genes that were uniquely regulated or showed further up- or downregulation. This study provides new insight into the regulation and ecological function of priming in maize. |
