Asymmetric adaptation to indolic and aliphatic glucosinolates in the B and Q sibling species of Bemisia tabaci (Hemiptera: Aleyrodidae)
Asymmetric adaptation to indolic and aliphatic glucosinolates in the B and Q sibling species of Bemisia tabaci (Hemiptera: Aleyrodidae)
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DOI：
10.1111/j.1365-294x.2012.05713.x
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发表时间：
2012-09-01
影响因子：
4.9
通讯作者：
Morin, S.
中科院分区：
文献类型：
--
作者：
Elbaz, M.;Halon, E.;Morin, S.
硫代葡萄糖苷在保护植物免受韧皮部饲养者如蚜虫和粉虱的侵害中所起的作用目前尚不清楚，因为这些食草动物可能会避免将来自韧皮部汁液的硫代葡萄糖苷与黑芥子酶接触。在这里，我们调查了高水平的脂肪族和吲哚硫代葡萄糖苷的生活史性状和解毒基因表达的两个兄弟物种，B和Q，烟粉虱。高浓度的硫代葡萄糖甙降低了两种蛾的平均产卵率，并降低了Q蛾的存活率和发育率。高浓度吲哚硫代葡萄糖苷降低了B种的产卵率和若虫期的存活率以及两种的发育率。分子分析揭示了两个主要的不对称性之间的B和Q物种。首先，特异性GST基因（BtGST 1和BtGST 2）在吲哚芥子油苷暴露过程中仅在Q中显著诱导。这可能反映了假定参与吲哚芥子油苷解毒的基因，并解释了物种在积累吲哚芥子油苷的植物上的良好表现。第二，分析的10个解毒基因中的8个的组成型表达在Q物种中高于在B物种中。有趣的是，其中四个基因在B中响应于高水平的硫代葡萄糖甙而被诱导。因此，似乎B和Q物种在其最佳防御策略上有所不同。B利用诱导防御，如果经历压力的概率很小，其严重性很低，那么这种防御是有利可图的，而Q则投入大量资源，随时准备迎接挑战。
The role glucosinolates play in defending plants against phloem feeders such as aphids and whiteflies is currently not clear as these herbivores may avoid bringing glucosinolates from the phloem sap into contact with myrosinase enzymes. Here, we investigated the effects of high levels of aliphatic and indolic glucosinolates on life history traits and detoxification gene expression in two sibling species, B and Q, of the whitefly Bemisia tabaci. High levels of aliphatic glucosinolates decreased the average oviposition rate of both species and reduced the survival and developmental rate of Q nymphs. High levels of indolic glucosinolates decreased the oviposition rate and survival of nymphal stages of the B species and the developmental rate of both species. Molecular analyses revealed two major asymmetries between the B and Q species. First, specific GST genes (BtGST1 and BtGST2) were significantly induced during exposure to indolic glucosinolates only in Q. This may reflect the genes putative involvement in indolic glucosinolates detoxification and explain the species good performance on plants accumulating indolic glucosinolates. Second, the constitutive expression of eight of the 10 detoxification genes analysed was higher in the Q species than in the B species. Interestingly, four of these genes were induced in B in response to high levels of glucosinolates. It seems, therefore, that the B and Q species differ in their optimal defence strategy. B utilizes inducible defences that are profitable if the probability of experiencing the stress is small and its severity is low, while Q invests significant resources in being always ready for a challenge.