Department of Agriculture, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, 1983969411 Tehran, Iran.
Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, 1983969411 Tehran, Iran.
J Appl Microbiol. 2024 Aug 5;135(8). doi: 10.1093/jambio/lxae199.
To identify promising fungal endophytes that are able to produce glycyrrhizin and enhance it in licorice and the mechanisms involved.
Fifteen fungal endophytes were isolated from Glycyrrhiza glabra L. rhizomes among which SGGF14 and SGGF21 isolates were found to produce glycyrrhizin by 4.29 and 2.58 µg g-1 dry weight in the first generation of their culture. These isolates were identified as Fusarium solani and Alternaria tenuissima, respectively, based on morphological characteristics and sequence analysis of internal transcribed spacer, TEF1, ATPase, and CAL regions. Subsequently, G. glabra plants were inoculated with these fungal isolates to examine their effect on glycyrrhizin production, plant growth parameters and the expression of key genes involved in glycyrrhizin pathway: SQS1, SQS2, bAS, CAS, LUS, CYP88D6, and CYP72A154. Endophytes were able to enhance glycyrrhizin content by 133%-171% in the plants. Natural control (NC) plants, harboring all natural endophytes, had better growth compared to SGGF14- and SGGF21-inoculated and endophyte-free (EF) plants. Expression of SQS1, SQS2, CYP88D6, and CYP72A154 was upregulated by inoculation with endophytes. LUS and CAS were downregulated after endophyte inoculation. Expression of bAS was higher in SGGF21-inoculated plants when compared with NC, EF, and SGGF14-inoculated plants.
Two selected fungal endophytes of G. glabra can produce glycyrrhizin and enhance glycyrrhizin content in planta by modulating the expression of key genes in glycyrrhizin biosynthetic pathway.
鉴定能够产生甘草酸并在甘草中增强其含量的有前途的真菌内生菌，以及涉及的机制。
从甘草根茎中分离出 15 种真菌内生菌，其中 SGGF14 和 SGGF21 分离株在其第一代培养物中分别产生 4.29 和 2.58μg g-1 干重的甘草酸。根据形态特征和内部转录间隔区、TEF1、ATPase 和 CAL 区域的序列分析，这两个分离株分别被鉴定为尖孢镰刀菌和细极链格孢。随后，将这些真菌分离物接种到甘草植物中，以检查它们对甘草酸产生、植物生长参数和参与甘草酸途径的关键基因表达的影响：SQS1、SQS2、bAS、CAS、LUS、CYP88D6 和 CYP72A154。内生菌能够使植物中的甘草酸含量提高 133%-171%。与 SGGF14 和 SGGF21 接种和无内生菌（EF）植物相比，含有所有天然内生菌的天然对照（NC）植物生长更好。接种内生菌后 SQS1、SQS2、CYP88D6 和 CYP72A154 的表达上调。接种内生菌后 LUS 和 CAS 的表达下调。与 NC、EF 和 SGGF14 接种植物相比，SGGF21 接种植物的 bAS 表达更高。
从甘草中选择的两种真菌内生菌能够产生甘草酸，并通过调节甘草酸生物合成途径中的关键基因表达来增强植物中的甘草酸含量。
