Alors David, Amses Kevin R, James Timothy Y, Boussiba Sammy, Zarka Aliza
Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, The Jacob Blaustein Institutes for Desert Research, Sede-Boker Campus Ben Gurion University of the Negev, Beersheba 8499000, Israel.
Departamento de Biología y Químicas, Facultad de Recursos Naturales, Campus San Juan Pablo II, Universidad Católica de Temuco, Temuco 478 0694, Chile.
J Fungi (Basel). 2022 May 25;8(6):561. doi: 10.3390/jof8060561.
Glutamine synthetase (GlnS) is a key enzyme in nitrogen metabolism. We investigated the effect of the GlnS inhibitor glufosinate on the infection of by the blastocladialean fungus , assuming that interfering with the host nitrogen metabolism will affect the success of the parasite. Complete inhibition of infection, which could be bypassed by the GlnS product glutamine, was observed at millimolar concentrations of glufosinate. However, this effect of glufosinate was attributed to its direct interaction with the blastoclad and not the host, which results in development and growth inhibition of the blastoclad. In our draft genome, we found that the sequence of GlnS is related to another fungal GlnS, type III, found in many poor known phyla of fungi, including Blastocladiomycota and Chytridiomycota, and absent in the main subkingdom of fungi, the Dikarya. We further tested the ability of the blastoclad to utilize nitrate and ammonia as inorganic nitrogen sources and glutamine for growth. We found that equally use ammonia and glutamine and use also nitrate, but with less efficiency. Altogether, our results show that GlnS type III is mandatory for the development and growth of and could be an efficient target to develop strategies for the control of the fungal parasite of .
谷氨酰胺合成酶（GlnS）是氮代谢中的关键酶。我们研究了谷氨酰胺合成酶抑制剂草铵膦对芽枝霉属真菌感染的影响，假定干扰宿主氮代谢会影响寄生虫的感染成功率。在毫摩尔浓度的草铵膦下观察到感染完全受到抑制，而谷氨酰胺合成酶的产物谷氨酰胺可以绕过这种抑制作用。然而，草铵膦的这种作用归因于它与芽枝霉的直接相互作用，而非与宿主的相互作用，这导致芽枝霉的发育和生长受到抑制。在我们的[未提及的物种]基因组草图中，我们发现谷氨酰胺合成酶的序列与另一种真菌谷氨酰胺合成酶（III型）相关，这种III型谷氨酰胺合成酶存在于许多鲜为人知的真菌门类中，包括芽枝霉门和壶菌门，而在真菌的主要亚界双核菌亚界中不存在。我们进一步测试了芽枝霉利用硝酸盐和氨作为无机氮源以及谷氨酰胺进行生长的能力。我们发现[未提及的物种]同样能利用氨和谷氨酰胺，也能利用硝酸盐，但效率较低。总之，我们的结果表明III型谷氨酰胺合成酶对[未提及的物种]的发育和生长是必不可少的，并且可能是开发控制[未提及的物种]真菌寄生虫策略的有效靶点。
