The transmembrane protein AaSho1 is essential for appressorium formation and secondary metabolism but dispensable for vegetative growth in pear fungal Alternaria alternata
The transmembrane protein AaSho1 is essential for appressorium formation and secondary metabolism but dispensable for vegetative growth in pear fungal Alternaria alternata
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DOI：
10.1016/j.funbio.2021.11.006
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发表时间：
2022-01-22
期刊：
影响因子：
2.5
通讯作者：
Prusky, Dov B.
中科院分区：
文献类型：
--
作者：
Liu, Yongxiang;Li, Yongcai;Prusky, Dov B.
高渗甘油反应（HOG）途径在链格孢菌的环境胁迫反应、分化和毒力中起着关键作用。已假定合成的高渗透压敏感传感器Sho 1调节HOG途径。为了研究Sho 1跨膜蛋白对植物营养生长、次生代谢和侵染结构形成的调控作用，本研究从拟南芥中克隆了Sho 1基因（AaSho 1）。alternata（JT-03）。序列分析表明，AaSho 1具有所有四个特征性的跨膜结构域和SH 3结构域存在于另一个Sho 1基因从几个丝状真菌。定量RT-PCR分析表明，果蜡提取物在体外显著上调了AaSho 1基因的表达。药理实验表明，A. AaSho 1特异性抑制剂制霉菌素处理对A. alternata的形态无明显影响。alternata和梨果实的入侵生长。但制霉菌素处理显著降低了孢子在不同涂蜡疏水表面上的萌发率，其中果蜡、蜂蜡和石蜡涂蜡处理的孢子萌发率分别降低了58.00%、46.70%和83.72%。同时，制霉菌素处理还影响了次级代谢产物谷丙转氨酶（ALT）、藤毒素（TEN）和黑色素含量。这些结果表明，AaSho 1基因在A. alternata响应宿主表面的生理化学信号。
The high-osmolarity glycerol response (HOG) pathway is pivotal in environmental stress response, differentiation and virulence of Alternaria alternata. The synthetic high osmolarity sensitive sensor Sho1 has been postulated to regulate the HOG pathway. To determine the regulatory role of transmembrane protein Sho1 on vegetative growth, secondary metabolism and infection structure formation, a gene (AaSho1) encoding Sho1 was cloned and characterized from A. alternata (JT-03). Sequence analysis showed that AaSho1 has all four characteristic transmembrane domains and the SH3 domain present in another Sho1 gene from several filamentous fungal. The quantitative RT-PCR analysis showed that fruit wax extract significantly up-regulated AaSho1 gene expression in vitro. Pharmacological experiments showed that A. alternata treated with nystatin, a specific AaSho1 inhibitor, had no significant effect on the morphology of A. alternata and the invasive growth in pear fruit. However, nystatin treatment signifi-cantly reduced spore germination rates on different wax-coated hydrophobic surfaces, with 58.00, 46.70 and 83.72% reduced for fruit wax, beeswax and paraffin coated. Meanwhile, the secondary metabolism altenuene (ALT), tentoxin (TEN) toxin, and melanin content were also affected by nystatin treatment. These findings suggest that AaSho1 is required for the infection structure differentiation and secondary metabolism of A. alternata in response to physiochemical signals on the host surfaces.