Glycogen catabolism, but not its biosynthesis, affects virulence of Fusarium oxysporum on the plant host
Glycogen catabolism, but not its biosynthesis, affects virulence of Fusarium oxysporum on the plant host
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DOI：
10.1016/j.fgb.2015.03.014
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发表时间：
2015-04-01
影响因子：
3
通讯作者：
Roncero, M. Isabel G.
中科院分区：
文献类型：
--
作者：
Corral-Ramos, Cristina;Roncero, M. Isabel G.
研究了真菌病原体尖镰孢中糖原代谢的作用。对负责糖原生物合成的基因进行靶向失活：编码糖原蛋白的 gnn1、编码糖原合成酶的 gls1 和编码糖原分支酶的 gbe1。此外，参与糖原分解代谢的基因也被删除：编码糖原磷酸化酶的gph1和编码糖原脱支酶的gdb1。野生型菌株在无菌培养物中生长期间，糖原储备稳步增加，14天后达到1500μg葡萄糖当量mg(-1)蛋白质。在缺乏生物合成基因的突变体中，糖原积累被消除，而糖原积累则分别增加了 20-40% 或 80%；在受分解代谢基因影响的单突变体和双突变体中。番茄植株感染期间糖原代谢基因的转录水平在接种后四天达到峰值，与无菌培养期间观察到的结果相似。在gdb突变体和野生型菌株之间观察到营养菌丝融合能力的显着差异。糖原代谢缺陷的单一突变体在无脊椎动物模型大蜡螟中表现出相似的毒力水平。有趣的是，在单突变体和双突变体背景下，与野生型相比，gdb1 的缺失使植物宿主的毒力降低了 40%，而其他突变体则显示出野生型水平的毒力。 (C) 2015 Elsevier Inc. 保留所有权利。
The role of glycogen metabolism was investigated in the fungal pathogen Fusarium oxysporum. Targeted inactivation was performed of genes responsible for glycogen biosynthesis: gnn1 encoding glycogenin, gls1 encoding glycogen synthase, and gbe1 encoding glycogen branching enzyme. Moreover genes involved in glycogen catabolism were deleted: gph1 encoding glycogen phosphorylase and gdb1 encoding glycogen de-branching enzyme. Glycogen reserves increased steadily during growth of the wild type strain in axenic cultures, to reach up to 1500 mu g glucose equivalents mg(-1) protein after 14 days. Glycogen accumulation was abolished in mutants lacking biosynthesis genes, whereas it increased by 20-40% or 80%, respectively; in the single and double mutants affected in catabolic genes. Transcript levels of glycogen metabolism genes during tomato plant infection peaked at four days post inoculation, similar to the results observed during axenic culture. Significant differences were observed between gdb mutants and the wild type strain for vegetative hyphal fusion ability. The single mutants defective in glycogen metabolism showed similar levels of virulence in the invertebrate animal model Galleria mellonella. Interestingly, the deletion of gdb1 reduced virulence on the plant host up to 40% compared to the wild type in single and in double mutant backgrounds, whereas the other mutants showed the virulence at the wild-type level. (C) 2015 Elsevier Inc. All rights reserved.