Cao He-He, Liu Hui-Ru, Zhang Zhan-Feng, Liu Tong-Xian
State Key Laboratory for Crop Stress Biology in Arid Areas, Yangling, Shaanxi, 712100, China.
Key Laboratory of Crop Pest Management on the Northwest Loess Plateau, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
Sci Rep. 2016 Feb 24;6:21954. doi: 10.1038/srep21954.
The green peach aphid, Myzus persicae Sulzer, is a notorious pest on vegetables, which often aggregates in high densities on crop leaves. In this study, we investigated whether M. persicae could suppress the resistance level of Chinese cabbage Brassica pekinensis. M. persicae performed better in terms of weight gain (33% increase) and population growth (110% increase) when feeding on previously infested (pre-infested) Chinese cabbage compared with those on non-infested plants. However, when given a choice, 64% of the aphids preferred to settle on non-infested leaves, while 29% of aphids chose pre-infested leaves that had a 2.9 times higher concentration of glucosinolates. Aphid feeding significantly enhanced the amino acid:sugar ratio of phloem sap and the absolute amino acid concentration in plant leaves. Aphid infestation significantly increased the expression levels of salicylic acid (SA) marker genes, while it had marginal effects on the expression of jasmonate marker genes. Exogenously applied SA or methyl jasmonate had no significant effects on M. persicae performance, although these chemicals increased glucosinolates concentration in plant leaves. M. persicae infestation increase amino acid:sugar ratio and activate plant defenses, but aphid performed better on pre-infested plants, suggesting that both nutrition and toxics should be considered in insect-plant interaction.
桃蚜（Myzus persicae Sulzer）是一种臭名昭著的蔬菜害虫，常以高密度聚集在作物叶片上。在本研究中，我们调查了桃蚜是否会抑制大白菜（Brassica pekinensis）的抗性水平。与取食未受侵染的大白菜相比，桃蚜取食先前已受侵染（预侵染）的大白菜时，在体重增加（约增加33%）和种群增长（约增加110%）方面表现更佳。然而，在有选择的情况下，64%的蚜虫更喜欢在未受侵染的叶片上定居，而29%的蚜虫选择了硫代葡萄糖苷浓度高出2.9倍的预侵染叶片。蚜虫取食显著提高了韧皮部汁液的氨基酸:糖比率以及植物叶片中的绝对氨基酸浓度。蚜虫侵染显著提高了水杨酸（SA）标记基因的表达水平，而对茉莉酸标记基因的表达影响较小。外源施用SA或茉莉酸甲酯对桃蚜的表现没有显著影响，尽管这些化学物质增加了植物叶片中硫代葡萄糖苷的浓度。桃蚜侵染增加了氨基酸:糖比率并激活了植物防御，但蚜虫在预侵染的植物上表现更好，这表明在昆虫与植物的相互作用中应同时考虑营养和毒性因素。
