Drought-tolerant fungal microbes, Aspergillus oryzae and Aspergillus fumigatus, elevate physiohormonal and antioxidant responses of maize under drought stress

Kiran Niaz; Mamoona Rauf; Muhammad Arif; Muhammad Hamayun; Humaira Gul; Abeer Hashem; Elsayed Fathi Abd Allah; Qiang-Sheng Wu

doi:10.3389/fmicb.2024.1488639

Drought-tolerant fungal microbes, Aspergillus oryzae and Aspergillus fumigatus, elevate physiohormonal and antioxidant responses of maize under drought stress

Front Microbiol. 2024 Nov 28:15:1488639. doi: 10.3389/fmicb.2024.1488639. eCollection 2024.

Authors

Kiran Niaz¹, Mamoona Rauf¹, Muhammad Arif², Muhammad Hamayun¹, Humaira Gul¹, Abeer Hashem³, Elsayed Fathi Abd Allah⁴, Qiang-Sheng Wu⁵

Affiliations

¹ Department of Botany, Abdul Wali Khan University Mardan, Mardan, Pakistan.
² Department of Biotechnology, Abdul Wali Khan University Mardan, Mardan, Pakistan.
³ Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.
⁴ Plant Production Department, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia.
⁵ College of Horticulture and Gardening, Yangtze University, Jingzhou, China.

Abstract

Introduction: Temporary and extended drought stress accelerates phytohormones and reactive oxygen species (ROS) in plants, however, the fate of the plants under stress is mostly determined by the metabolic and molecular reprogramming, which can be modulated by the application of habitat-adapted fungi that triggers resistance to stress upon symbiotic association.

Methods: The present research exhibited the exploitation of the newly isolated, drought habitat-adapted fungal endophytic consortium of SAB (Aspergillus oryzae) and CBW (Aspergillus fumigatus), on maize under drought stress. SAB and CBW primarily hosted the root tissues of Conyza bonariensis L., which have not been reported earlier, and sufficiently produced growth-promoting metabolites and antioxidants.

Results: SAB and CBW adeptly inhabited the maize roots. They promoted biomass, primary metabolites, osmolytes (protein, sugar, lipids, proline, phenolics, flavonoids), and IAA production while reducing tannins, ABA, and H₂O₂ contents and increasing antioxidant enzyme activities. In addition, the enhanced adventitious root development at the root/stem interface, and elongated main root development optimum stomatal activity of SAB- and CBW-inoculated maize plants were observed under drought stress. SAB and CBW modulated the expression of the ZmBSK1, ZmAPX, and ZmCAT1 genes in the maize shoot and root tissues under drought stress vs. control, signifying an essential regulatory function for SAB/CBW-induced drought stress tolerance via phytohormonal signaling pathway leading to the antioxidant upregulation.

Discussion: These findings imply that the exogenous administration of the SAB/CBW consortium might be a rather efficient strategy that contributes to optimizing the physio-hormonal attributes and antioxidant potential to alleviate the drought stress in maize.

Keywords: beneficial fungal microbes; drought stress; maize; metabolites; phytohormones; plant–microbe interaction.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. The authors would like to extend their sincere appreciation to the Researchers Supporting Project Number (RSP2025R356), King Saud University, Riyadh, Saudi Arabia.