<i>Coix</i> herbivory candidate genes primers.

<div><p><i>Coix lacryma-jobi</i> L. belongs to family Poaceae, is widely cultivated in tropical Asian countries for its nutritional and medicinal values. <i>Coix</i> is often threatened by lepidopteran such as <i>Mythimna separata</i> during its life cycle, resulting in severe yield reduction. Insect feeding can trigger defense signaling and increased defense responses in many other crops, yet little is known about whether simulated armyworm feeding on <i>Coix</i> leaves could induce anti-herbivory responses and whether armyworm feeding could activate priming in systemic leaves. In this study, <i>Mythimna separata</i> simulated herbivory elicited increased jasmonic acid (JA) level, JA-Ile (JA-isoleucine conjugate) and altered transcriptome in the <i>Coix</i> leaves. Meanwhile, <i>M</i>. <i>separata</i> simulated herbivory in local leaves primed the systemic leaves for increased accumulation of jasmonic acid and enhanced resistance to <i>M</i>. <i>separata</i>. Consistently, transcriptome analysis showed the systemic leaves were primed, which were up- or down-regulated comparing with the non-primed systemic leaves. In this study, we first reported <i>Mythimna separata</i> simulated herbivory induced increased defense response in leaves of <i>Coix</i>, <i>also Mythimna separata</i> herbivory primed <i>Coix</i> resistance in systemic leaves. This study provides new insight into the regulation of defense responses of <i>Coix</i> against <i>M</i>. <i>separata</i> and the ecological function of priming in <i>Coix</i>.</p></div>