摘要 : Oxylipins function as signaling molecules in plant growth and development and contribute to defense against stress. Here, we show that oxylipins also facilitate infestation of <i>Arabidopsis thaliana</i> shoots by the phloem sap-c... 展开 Oxylipins function as signaling molecules in plant growth and development and contribute to defense against stress. Here, we show that oxylipins also facilitate infestation of <i>Arabidopsis thaliana</i> shoots by the phloem sap-consuming green peach aphid (GPA; <i>Myzus persicae</i>), an agronomically important insect pest. GPAs had difficulty feeding from sieve elements and tapping into the xylem of <i>lipoxygenase5</i> (<i>lox5</i>) mutant plants defective in LOX activity. These defects in GPA performance in the <i>lox5</i> mutant were accompanied by reduced water content of GPAs and a smaller population size of GPAs in the mutant compared with the wild-type plant. <i>LOX5</i> expression was rapidly induced in roots in response to infestation of shoots by GPAs. In parallel, levels of <i>LOX5</i>-derived oxylipins increased in roots and in petiole exudates of GPA-colonized plants. Application of 9-hydroxyoctadecadienoic acid (an oxylipin produced by the LOX5 enzyme) to roots restored water content and GPA population size in <i>lox5</i> plants, thus confirming that a <i>LOX5</i>-derived oxylipin promotes infestation of the foliage by GPAs. Micrografting experiments demonstrated that GPA performance on foliage is influenced by the <i>LOX5</i> genotype in roots, thus demonstrating the importance of root-derived oxylipins in colonization of aboveground organs by an insect. 收起