Reciprocal oxylipin-mediated cross-talk in the Aspergillus-seed pathosystem
Reciprocal oxylipin-mediated cross-talk in the Aspergillus-seed pathosystem
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DOI：
10.1111/j.1365-2958.2007.06045.x
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发表时间：
2008-01-01
影响因子：
3.6
通讯作者：
Keller, Nancy P.
中科院分区：
文献类型：
--
作者：
Brodhagen, Marion;Tsitsigiannis, Dimitrios I.;Keller, Nancy P.
在曲霉中，霉菌毒素的产生和孢子形成部分受内源性氧脂素（含氧的多不饱和脂肪酸及其衍生的代谢物）调控。在构巢曲霉中，氧脂素由双加氧酶PpoA、PpoB和PpoC合成。结构相似的氧脂素通过脂氧合酶（LOX）在种子中合成。先前的报道表明，向曲霉培养物中外源施加种子氧脂素会改变孢子形成和霉菌毒素的产生。在此，我们探究了一种植物氧脂素生物合成基因（ZmLOX3）是否能在功能上替代构巢曲霉的ppo基因。我们将ZmLOX3导入野生型构巢曲霉以及一个氧脂素、分生孢子和霉菌毒素柄曲霉素产量降低的ΔppoAC菌株中。ZmLOX3的表达在两种背景下都增加了分生孢子和柄曲霉素的产量。我们还探究了构巢曲霉的氧脂素在曲霉侵染过程中是否影响种子LOX基因的表达。我们观察到，与野生型感染相比，花生种子pnlox2 - 3的表达在被构巢曲霉Δppo突变体感染时降低。这一结果提供了遗传证据，表明真菌氧脂素参与植物LOX基因表达的变化，从而可能导致真菌/宿主相互作用的改变。本报告为曲霉 - 种子病理系统中氧脂素的相互作用提供了首个遗传学证据。
In Aspergilli, mycotoxin production and sporulation are governed, in part, by endogenous oxylipins (oxygenated, polyunsaturated fatty acids and metabolites derived therefrom). In Aspergillus nidulans, oxylipins are synthesized by the dioxygenase enzymes PpoA, PpoB and PpoC. Structurally similar oxylipins are synthesized in seeds via the action of lipoxygenase (LOX) enzymes. Previous reports have shown that exogenous application of seed oxylipins to Aspergillus cultures alters sporulation and mycotoxin production. Herein, we explored whether a plant oxylipin biosynthetic gene (ZmLOX3) could substitute functionally for A. nidulans ppo genes. We engineered ZmLOX3 into wild-type A. nidulans, and into a Delta ppoAC strain that was reduced in production of oxylipins, conidia and the mycotoxin sterigmatocystin. ZmLOX3 expression increased production of conidia and sterigmatocystin in both backgrounds. We additionally explored whether A. nidulans oxylipins affect seed LOX gene expression during Aspergillus colonization. We observed that peanut seed pnlox2-3 expression was decreased when infected by A. nidulans Delta ppo mutants compared with infection by wild type. This result provides genetic evidence that fungal oxylipins are involved in plant LOX gene expression changes, leading to possible alterations in the fungal/host interaction. This report provides the first genetic evidence for reciprocal oxylipin cross-talk in the Aspergillus-seed pathosystem.