Trehalose 6-phosphate phosphatase is required for development, virulence and mycotoxin biosynthesis apart from trehalose biosynthesis in Fusarium graminearum
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- 作者：Xiu-Shi Song ; He-Ping Li ; Jing-Bo Zhang ; Bo Song ; Tao Huang ; Xiao-Min Du ; An-Dong Gong ; Yi-Ke Liu ; Yan-Ni Feng ; Rebecca S. Agboola ; Yu-Cai Liao
- 关键词：Cell polarity ; Development ; Fusarium graminearum ; Mycotoxin ; Trehalose 6-phosphate phosphatase ; Virulence
- 刊名：Fungal Genetics and Biology
- 出版年：February, 2014
- 年：2014
- 卷：63
- 期：Complete
- 页码：24-41
- 全文大小：2737 K
文摘
Trehalose 6-phosphate synthase (TPS1) and trehalose 6-phosphate phosphatase (TPS2) are required for trehalose biosynthesis in yeast and filamentous fungi, including Fusarium graminearum. Three null mutants 螖tps1, 螖tps2 and 螖tps1-螖tps2, each carrying either a single deletion of TPS1 or TPS2 or a double deletion of TPS1-TPS2, were generated from a toxigenic F. graminearum strain and were not able to synthesize trehalose. In contrast to its reported function in yeasts and filamentous fungi, TPS1 appeared dispensable for development and virulence. However, deletion of TPS2 abolished sporulation and sexual reproduction; it also altered cell polarity and ultrastructure of the cell wall in association with reduced chitin biosynthesis. The cell polarity alteration was exhibited as reduced apical growth and increased lateral growth and branching with increased hyphal and cell wall widths. Moreover, the TPS2-deficient strain displayed abnormal septum development and nucleus distribution in its conidia and vegetative hyphae. The 螖tps2 mutant also had 62% lower mycelial growth on potato dextrose agar and 99% lower virulence on wheat compared with the wild-type. The 螖tps1, 螖tps2 and 螖tps1-螖tps2 mutants synthesized over 3.08-, 7.09- and 2.47-fold less mycotoxins, respectively, on rice culture compared with the wild-type. Comparative transcriptome analysis revealed that the 螖tps1, 螖tps2 and 螖tps1-螖tps2 mutants had 486, 1885 and 146 genotype-specific genes, respectively, with significantly changed expression profiles compared with the wild-type. Further dissection of this pathway will provide new insights into regulation of fungal development, virulence and trichothecene biosynthesis.