College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, People's Republic of China.
Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, 150040, People's Republic of China.
Appl Microbiol Biotechnol. 2023 Mar;107(5-6):1931-1946. doi: 10.1007/s00253-023-12437-z. Epub 2023 Feb 17.
Pigeon pea hairy root cultures (PPHRCs) have been proven to be a promising alternative for the production of health-beneficial phenolic compounds, such as the most important health-promoting compound, i.e., cajaninstilbene acid (CSA). In this study, PPHRCs were cocultured with live Aspergillus fungi for further improving phenolic productivity via biological elicitation. Aspergillus oryzae CGMCC 3.951 (AO 3.951) was found to be the optimal fungus that could achieve the maximum increment of CSA (10.73-fold increase) in 42-day-old PPHRCs under the inoculum size of mycelia 0.50% and cocultivation time 36 h. More precisely, the contents of CSA in hairy roots and culture media after fungal elicitation increased by 9.87- and 62.18-fold over control, respectively. Meanwhile, the contents of flavonoid glycosides decreased, while aglycone yields increased upon AO 3.951 elicitation. Moreover, AO 3.951 could trigger the oxidative stress and pathogen defense response thus activating the expression of biosynthesis- and ABC transporter-related genes, which contributed to the intracellular accumulation and extracellular secretion of phenolic compounds (especially CSA) in PPHRCs. And PAL2, 4CL2, STS1, and I3'H were likely to be the potential key enzyme genes regulating the biosynthesis of CSA, and ABCB11X1-1, ABCB11, and ABCG24X2 were closely related to the transmembrane transport of CSA. Overall, the cocultivation approach could make PPHRCs more commercially attractive for the production of high-value phenolic compounds such as CSA and flavonoid aglycones in nutraceutical/medicinal fields. And the elucidation of crucial biosynthesis and transport genes was important for systematic metabolic engineering aimed at increasing CSA productivity. KEY POINTS: • Cocultivation of PPHRCs and live fungi was to enhance CSA production and secretion. • PPHRCs augmented CSA productivity 10.73-fold when cocultured with AO 3.951 mycelia. • Several biosynthesis and transport genes related to CSA production were clarified.
兵豆毛状根培养物（PPHRCs）已被证明是生产有益健康的酚类化合物的一种很有前途的替代方法，例如最重要的促进健康的化合物，即冈比亚槐素酸（CSA）。在这项研究中，通过生物激发作用，将 PPHRC 与活曲霉真菌共培养，以进一步提高酚类化合物的生产力。发现米曲霉 CGMCC 3.951（AO 3.951）是最佳真菌，可以在接种量为菌丝 0.50%和共培养时间 36 h 的条件下，使 42 天龄的 PPHRC 中的 CSA 达到最大增量（增加 10.73 倍）。更准确地说，在真菌激发后，毛状根和培养基中 CSA 的含量分别比对照增加了 9.87-和 62.18 倍。同时，黄酮糖苷的含量降低，而 AO 3.951 激发后糖苷的产率增加。此外，AO 3.951 可以引发氧化应激和病原体防御反应，从而激活生物合成和 ABC 转运体相关基因的表达，有助于酚类化合物（特别是 CSA）在 PPHRC 中的细胞内积累和细胞外分泌。并且 PAL2、4CL2、STS1 和 I3'H 可能是调节 CSA 生物合成的潜在关键酶基因，而 ABCB11X1-1、ABCB11 和 ABCG24X2 与 CSA 的跨膜转运密切相关。总的来说，共培养方法可以使 PPHRC 更具商业吸引力，可用于生产高价值的酚类化合物，如 CSA 和营养/药用领域的黄酮苷元。阐明关键的生物合成和转运基因对于旨在提高 CSA 产量的系统代谢工程很重要。关键点： • PPHRCs 与活真菌共培养以提高 CSA 产量和分泌。 • PPHRCs 与 AO 3.951 菌丝共培养可将 CSA 产量提高 10.73 倍。 • 阐明了与 CSA 产生相关的几个生物合成和转运基因。
