Data_Sheet_2_Contrasting effects of NADPH oxidases on the fungal hyphae growth and immune responses in Pleurotus ostreatus.DOCX

Pleurotus ostreatus is one of the most consumed mushroom species, as it serves as a high-quality food, favors a rich secondary metabolism, and has remarkable adaptability to the environment and predators. In this study, we investigated the function of two key reactive oxygen species producing enzyme NADPH oxidase (PoNoxA and PoNoxB) in P. ostreatus hyphae growth, metabolite production, signaling pathway activation, and immune responses to different stresses. Characterization of the Nox mutants showed that PoNoxB played an important role in the hyphal formation of the multicellular structure, while PoNoxA regulated apical dominance. The ability of P. ostreatus to tolerate a series of abiotic stress conditions (e.g., osmotic, oxidative, membrane, and cell-wall stresses) and mechanical damage repair was enhanced with PoNoxA over-expression. PoNoxB had a greater responsibility in regulating the polysaccharide composition of the cell wall and methyl jasmonate and gibberellin GA1 biosynthesis, and improved mushroom resistance against Tyrophagus putrescentiae. Moreover, mutants were involved in the jasmonate and GA signaling pathway, and toxic protein defense metabolite production. Our findings shed light on how the oyster mushroom senses stress signals and responds to adverse environments by the complex regulators of Noxs.

平菇（Pleurotus ostreatus）是全球消费量最高的食用菌物种之一，因其可作为优质食材、具备丰富的次级代谢产物合成能力，且对环境与天敌具有出色的适应性。本研究以平菇为材料，解析了两种产活性氧关键酶——烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NADPH oxidase，PoNoxA与PoNoxB）在平菇菌丝生长、代谢产物合成、信号通路激活以及应对不同胁迫的免疫响应中的功能。对Nox突变体的表型分析显示，PoNoxB在平菇多细胞结构的菌丝形成过程中发挥关键作用，而PoNoxA则调控菌丝的顶端优势。过表达PoNoxA可显著提升平菇对一系列非生物胁迫（如渗透胁迫、氧化胁迫、膜损伤胁迫与细胞壁胁迫）的耐受能力，同时增强其机械损伤修复能力。PoNoxB则主要参与调控细胞壁多糖组成、茉莉酸甲酯与赤霉素GA1的生物合成，同时可增强平菇对腐食酪螨（Tyrophagus putrescentiae）的抗性。此外，相关Nox突变体实验表明，Nox酶参与茉莉酸与赤霉素信号通路，并介导防御性毒性蛋白类代谢产物的合成。本研究结果揭示了平菇如何通过Nox酶的复杂调控网络感知胁迫信号并响应不良环境。