You Xiao-Xu, Li Xiao-Gang, Zhang Xing-Kai, Gu Wen, Chen Di, He Sen, Cao Guan-Hua
School of Chinese Materia Medica and Chinese Pharmaceutical Research International Science and Technology Cooperation Base of Yunnan University of Chinese Medicine, Kunming 650500, China.
State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Beijing 100700, China.
J Fungi (Basel). 2025 May 14;11(5):374. doi: 10.3390/jof11050374.
This study aims to evaluate the tolerance of an endophytic fungus isolated from the fibrous roots of Franch. to arsenic (As) and elucidate the underlying physiological and molecular mechanisms. The filamentous fungus is identified as based on morphological characteristics and phylogenetic tree analysis, belonging to the family Moniliaceae and Phyla Hyphomycetes. The tolerance of to As(V) was assessed by measuring its biomass under varying concentrations of As(V). The fungus exhibited remarkable As(V) tolerance, with an EC value of 2051.94 mg/L, and accumulated high concentrations of As in its mycelium. Subcellular distribution analysis revealed that As was predominantly localized in the cell wall fraction, with levels 4.06 times higher than those in the non-cell wall fraction. Notably, the concentrations of total organic As and As(III) in the mycelium were 852.75 μg/g and 24.94 μg/g, respectively, with conversion ratios of 76.64% and 2.24%. The organic As levels significantly surpassed both As(V) and As(III) concentrations in all cellular fractions (cell wall and non-cell wall components), demonstrating particularly efficient As transformation in . Under As(V) stress, the membrane antioxidant system, including superoxide dismutase (SOD), metallothionein (MT), glutathione (GSH), and melanin, was activated and significantly enhanced to mitigate oxidative damage. Transcriptomic analysis identified 4771 differentially expressed genes (DEGs; 2527 upregulated), including highly expressed As-responsive genes (, , 3, , and _). Strong correlations emerged between As speciation (total/organic/As(V)/As(III)), antioxidant levels, and DEG expression patterns. Taken together, these findings demonstrate that employs a multi-faceted As detoxification strategy involving subcellular distribution and reductive transformation (As(V) to As(III)/organic As), antioxidant system enhancement, transcriptomic adaptations, and integrated defense strategy. This work highlights potential for As bioremediation and elucidates As accumulation mechanisms in .
本研究旨在评估从 Franch. 的须根中分离出的一种内生真菌对砷（As）的耐受性，并阐明其潜在的生理和分子机制。基于形态特征和系统发育树分析，该丝状真菌被鉴定为属于链格孢科和半知菌门。通过测量其在不同浓度五价砷（As(V)）下的生物量来评估其对 As(V) 的耐受性。该真菌表现出显著的 As(V) 耐受性，其半数效应浓度（EC）值为 2051.94 mg/L，并且在其菌丝体中积累了高浓度的 As。亚细胞分布分析表明，As 主要定位于细胞壁部分，其含量比非细胞壁部分高 4.06 倍。值得注意的是，菌丝体中总有机砷和三价砷（As(III)）的浓度分别为 852.75 μg/g 和 24.94 μg/g，转化率分别为 76.64% 和 2.24%。所有细胞组分（细胞壁和非细胞壁成分）中的有机砷水平均显著超过 As(V) 和 As(III) 的浓度，表明该真菌在砷转化方面特别高效。在 As(V) 胁迫下，包括超氧化物歧化酶（SOD）、金属硫蛋白（MT）、谷胱甘肽（GSH）和黑色素在内的膜抗氧化系统被激活并显著增强，以减轻氧化损伤。转录组分析鉴定出 4771 个差异表达基因（DEGs；2527 个上调），包括高表达的 As 响应基因（、、3、和_）。As 形态（总/有机/As(V)/As(III)）、抗氧化剂水平和 DEG 表达模式之间出现了强相关性。综上所述，这些发现表明该真菌采用了多方面的 As 解毒策略，包括亚细胞分布和还原转化（As(V) 转化为 As(III)/有机 As）、增强抗氧化系统、转录组适应以及综合防御策略。这项工作突出了该真菌在 As 生物修复方面的潜力，并阐明了其体内 As 的积累机制。
