Zhu Hong, Zhang Jian, Gao Qi, Pang Guan, Sun Tingting, Li Rong, Yu Zhenzhong, Shen Qirong
Jiangsu Provincial Key Laboratory for Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
National Engineering Research Center for Organic-Based Fertilizers, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
Environ Microbiol. 2021 Oct;23(10):5784-5801. doi: 10.1111/1462-2920.15493. Epub 2021 Jul 14.
Hypocrealean Trichoderma are the most extensively studied facultative mycoparasites against phytopathogenic fungi. Aerial hyphae of Trichoderma guizhouense can rapidly proliferate over Fusarium oxysporum hyphae, cause sporadic cell death and arrest the growth of the host. The results of the present study demonstrated that a unique short-chain dehydrogenase/reductase (SDR), designated as TgSDR1, was expressed at a high level in T. guizhouense challenged by the hosts. Similar to other SDRs family members, the TgSDR1 protein contains a cofactor-binding motif and a catalytic site. The subcellular localization assay revealed that the TgSDR1::GFP fusion protein translocated to lipid droplets in mycelia and conidia. The data obtained using reverse genetic approach indicated that TgSDR1 is associated with antifungal ability, plays an important role in providing reducing equivalents in the form of NADPH and regulates the amino sugar and nucleotide sugar metabolism in T. guizhouense upon encountering a host. Moreover, the TgSDR1 deletion mutant was defective in conidiation. Thus, TgSDR1 functions as a key metabolic enzyme in T. guizhouense to regulate mycotrophic interactions, defence against other fungi, such as F. oxysporum, and conidiation.
肉座菌属木霉是针对植物病原真菌研究最广泛的兼性真菌寄生菌。贵州木霉的气生菌丝能够在尖孢镰刀菌的菌丝上快速增殖，导致散在的细胞死亡并抑制宿主生长。本研究结果表明，一种独特的短链脱氢酶/还原酶（SDR），命名为TgSDR1，在受宿主挑战的贵州木霉中高水平表达。与其他SDR家族成员相似，TgSDR1蛋白包含一个辅因子结合基序和一个催化位点。亚细胞定位分析表明，TgSDR1::GFP融合蛋白转运至菌丝体和分生孢子中的脂滴。采用反向遗传学方法获得的数据表明，TgSDR1与抗真菌能力相关，在以NADPH形式提供还原当量方面发挥重要作用，并在贵州木霉遇到宿主时调节氨基糖和核苷酸糖代谢。此外，TgSDR1缺失突变体在产孢方面存在缺陷。因此，TgSDR1作为贵州木霉中的一种关键代谢酶，可调节菌根营养相互作用、抵御其他真菌（如尖孢镰刀菌）以及产孢。
