Paulmann Maria K, Wegner Linus, Gershenzon Jonathan, Furch Alexandra C U, Kunert Grit
Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Str. 8, D-07745 Jena, Germany.
Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Dornburger Straße 159, D-07743 Jena, Germany.
Plants (Basel). 2023 May 6;12(9):1888. doi: 10.3390/plants12091888.
Although phloem-feeding insects such as aphids can cause significant damage to plants, relatively little is known about early plant defenses against these insects. As a first line of defense, legumes can stop the phloem mass flow through a conformational change in phloem proteins known as forisomes in response to Ca influx. However, specialized phloem-feeding insects might be able to suppress the conformational change of forisomes and thereby prevent sieve element occlusion. To investigate this possibility, we triggered forisome dispersion through application of a local heat stimulus to the leaf tips of pea (), clover () and broad bean () plants infested with different pea aphid () host races and monitored forisome responses. Pea aphids were able to suppress forisome dispersion, but this depended on the infesting aphid host race, the plant species, and the age of the plant. Differences in the ability of aphids to suppress forisome dispersion may be explained by differences in the composition and quantity of the aphid saliva injected into the plant. Various mechanisms of how pea aphids might suppress forisome dispersion are discussed.
尽管诸如蚜虫等取食韧皮部的昆虫会对植物造成严重损害，但人们对植物早期抵御这些昆虫的防御机制了解相对较少。作为第一道防线，豆类植物能够通过韧皮部蛋白（称为“成束收缩蛋白”）响应钙离子内流时的构象变化来阻止韧皮部的物质流动。然而，专门取食韧皮部的昆虫或许能够抑制成束收缩蛋白的构象变化，从而防止筛管分子堵塞。为了探究这种可能性，我们通过对感染了不同豌豆蚜寄主种群的豌豆、三叶草和蚕豆植株的叶尖施加局部热刺激来引发成束收缩蛋白的分散，并监测成束收缩蛋白的反应。豌豆蚜能够抑制成束收缩蛋白的分散，但这取决于侵染的蚜虫寄主种群、植物种类以及植物的年龄。蚜虫抑制成束收缩蛋白分散能力的差异可能是由于注入植物体内的蚜虫唾液的成分和数量不同所致。文中讨论了豌豆蚜抑制成束收缩蛋白分散的各种机制。
