Biogenic carbon quantum dots from marine endophytic fungi (Aspergillus flavus) to enhance the curcumin production and growth in Curcuma longa L

• Published in: Plant physiology and biochemistry 2024-06, Vol.211, p.108644-108644, Article 108644
• Main Authors: Vasanthkumar, Rajkumar, Baskar, Venkidasamy, Vinoth, Sathasivam, Roshna, Kattilaparambil, Mary, Thomas Nancy, Alagupandi, Raman, Saravanan, Krishnagowdu, Radhakrishnan, Ramalingam, Arun, Muthukrishnan, Gurusaravanan, Packiaraj
• Format: Article
• Language: English
• Subjects: Antioxidant enzyme; Aspergillus flavus; Carbon Quantum dots; Curcuma longa L; Endophytic fungus
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2024.108644

In this study, we have investigated the effect of carbon quantum dots (FM-CQDs) synthesized from marine fungal extract on Curcuma longa to improve the plant growth and curcumin production. The isolated fungus, Aspergillus flavus has produced a high amount of indole-3-acetic acid (IAA) (0.025 mg g-1), when treated with tryptophan. CQDs were synthesized from the A. flavus extract and it was characterized using ultraviolet visible spectrophotometer (UV–Vis) and high-resolution transmission electron microscopy (HR-TEM). The synthesized CQDs were excited at 365 nm in an UV–Vis and the HR-TEM analysis showed approximately 7.4 nm in size with a spherical shape. Both fungal crude extract (FCE) at 0–100 mg L−1 and FM-CQDs 0–5 mg L−1 concentrations were tested on C. longa. About 80 mg L−1 concentration FCE treated plants has shown a maximum height of 21 cm and FM-CQDs at 4 mg L−1 exhibited a maximum height of 25 cm compared to control. The FM-CQDs significantly increased the photosynthetic pigments such as total chlorophyll (1.08 mg g−1 FW) and carotenoids (17.32 mg g−1 FW) in C. longa. Further, antioxidant enzyme analysis confirmed that the optimum concentrations of both extracts did not have any toxic effects on the plants. FM-CQDs treated plants increased the curcumin content up to 0.060 mg g−1 by HPLC analysis. Semi quantitative analysis revealed that FCE and FM-CQDs significantly upregulated ClCURS1 gene expression in curcumin production. Schematic representation of FCE and FM-CQDs and its impact on Curcuma longa L. [Display omitted] •FM-CQDs were synthesized by a cost-effective hydrothermal method.•FM-CQD treatment significantly increased plant height compared to the control group.•FM-CQD treatment enhanced levels of chlorophyll contents and carotenoids in C. longa.•FM-CQD treatment increased antioxidant enzyme activity (SOD, POD, and CAT).•FCE and FM-CQDs both promoted curcumin biosynthesis via gene expression.