在高等真菌中,赖氨酸是通过α-氨基己二酸(AAA)途径生物合成的,这不同于植物,细菌,和较低的真菌。这些差异为开发植物寄生线虫的生物防治的分子调控策略提供了独特的机会,基于线虫诱捕真菌。在这项研究中,在线虫诱捕真菌模型中,我们表征了AAA通路中的核心基因,编码α-氨基己二酸还原酶(Aoaar),通过序列分析和比较生长,野生型和Aoaar敲除菌株的生化和整体代谢谱。Aoaar不仅具有α-氨基己二酸还原酶活性,提供真菌L-赖氨酸生物合成,但它也是非核糖体肽生物合成基因簇的核心基因。与WT相比,增长率,分生孢子生产,形成的捕食环的数量,ΔAoaar菌株的线虫摄食率降低了40-60%,36%,32%,52%,分别。氨基酸代谢,肽和类似物的生物合成,苯丙素类和聚酮化合物的生物合成,在ΔAoaar菌株中,脂质代谢和碳代谢被代谢重编程。Aoaar的破坏扰乱了赖氨酸代谢途径中中间体的生物合成,然后重新编程氨基酸和氨基酸相关的次级代谢,最后,它阻碍了A的生长和杀线虫能力。本研究为揭示氨基酸相关的初级和次级代谢在线虫捕获中的作用提供了重要参考。并证实了Aoarr作为调控线虫诱捕真菌生物防治线虫的分子靶标的可行性。
In higher fungi, lysine is biosynthesized via the α-aminoadipate (AAA) pathway, which differs from plants, bacteria, and lower fungi. The differences offer a unique opportunity to develop a molecular regulatory strategy for the biological control of plant parasitic nematodes, based on nematode-trapping fungi. In this study, in the nematode-trapping fungus model Arthrobotrys oligospora, we characterized the core gene in the AAA pathway, encoding α-aminoadipate reductase (Aoaar), via sequence analyses and through comparing the growth, and biochemical and global metabolic profiles of the wild-type and Aoaar knockout strains. Aoaar not only has α-aminoadipic acid reductase activity, which serves fungal L-lysine biosynthesis, but it also is a core gene of the non-ribosomal peptides biosynthetic gene cluster. Compared with WT, the growth rate, conidial production, number of predation rings formed, and nematode feeding rate of the ΔAoaar strain were decreased by 40-60%, 36%, 32%, and 52%, respectively. Amino acid metabolism, the biosynthesis of peptides and analogues, phenylpropanoid and polyketide biosynthesis, and lipid metabolism and carbon metabolism were metabolically reprogrammed in the ΔAoaar strains. The disruption of Aoaar perturbed the biosynthesis of intermediates in the lysine metabolism pathway, then reprogrammed amino acid and amino acid-related secondary metabolism, and finally, it impeded the growth and nematocidal ability of A. oligospora. This study provides an important reference for uncovering the role of amino acid-related primary and secondary metabolism in nematode capture by nematode-trapping fungi, and confirms the feasibility of Aoarr as a molecular target to regulate nematode-trapping fungi to biocontrol nematodes.