Dual Inoculation with <i>Rhizophagus irregularis</i> and <i>Bacillus megaterium</i> Improves Maize Tolerance to Combined Drought and High Temperature Stress by Enhancing Root Hydraulics, Photosynthesis and Hormonal Responses
Climate change is leading to combined drought and high temperature stress in many areas, drastically reducing crop production, especially for high-water-consuming crops such as maize. This study aimed to determine how the co-inoculation of an arbuscular mycorrhizal (AM) fungus (<i>Rhizophagus...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/6/5193 |
| Summary: | Climate change is leading to combined drought and high temperature stress in many areas, drastically reducing crop production, especially for high-water-consuming crops such as maize. This study aimed to determine how the co-inoculation of an arbuscular mycorrhizal (AM) fungus (<i>Rhizophagus irregularis</i>) and the PGPR <i>Bacillus megaterium</i> (Bm) alters the radial water movement and physiology in maize plants in order to cope with combined drought and high temperature stress. Thus, maize plants were kept uninoculated or inoculated with <i>R. irregularis</i> (AM), with <i>B. megaterium</i> (Bm) or with both microorganisms (AM + Bm) and subjected or not to combined drought and high temperature stress (D + T). We measured plant physiological responses, root hydraulic parameters, aquaporin gene expression and protein abundances and sap hormonal content. The results showed that dual AM + Bm inoculation was more effective against combined D + T stress than single inoculation. This was related to a synergistic enhancement of efficiency of the phytosystem II, stomatal conductance and photosynthetic activity. Moreover, dually inoculated plants maintained higher root hydraulic conductivity, which was related to regulation of the aquaporins <i>ZmPIP1;3</i>, <i>ZmTIP1.1</i>, <i>ZmPIP2;2</i> and <i>GintAQPF1</i> and levels of plant sap hormones. This study demonstrates the usefulness of combining beneficial soil microorganisms to improve crop productivity under the current climate-change scenario. |
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| ISSN: | 1661-6596 1422-0067 |