Distinct interactions of ericoid mycorrhizae and plant growth-promoting bacteria: impacts on blueberry growth and heat resilience

ABSTRACT

Blueberries confront substantial challenges from climate change, such as rising temperatures and extreme heat, necessitating urgent solutions to ensure productivity. We hypothesized that ericoid mycorrhizal fungi (ErM) and plant growth-promoting bacteria (PGPB) would establish symbiotic relationships and increase heat stress tolerance in blueberries. A growth chamber study was designed with low (25/20°C) and high temperature (35/30°C) conditions with micropropagated blueberry plantlets inoculated with ErM, PGPB, and both. Gas exchange and chlorophyll fluorescence properties of the leaves were monitored throughout the growth. At harvest, biochemical assays and biomass analysis were performed to evaluate potential oxidative stress induced by elevated temperatures. ErM application boosted root biomass under 25/20°C conditions but did not impact photosynthetic efficiency. In contrast, PGPB demonstrated a dual role: enhancing photosynthetic capacity and reducing stomatal conductance notably under 35/30°C conditions. Moreover, PGPB showcased conflicting effects, reducing oxidative damage under 25/20°C conditions while intensifying it during 47°C heat shock. A significant highlight lies in the opposing effects of ErM and PGPB on root growth and stomatal conductance, signifying their reciprocal influence on blueberry plant behavior, which may lead to increased water uptake or reduced water use. Understanding these complex interactions holds promise for refining sustainable strategies to overcome climate challenges.

KEYWORDS:

• 1 ericoid mycorrhizae
• 2 plant growth-promoting bacteria
• 3 plant-microbe interactions
• 4 stomatal behavior
• 5 leaf gas exchange
• 6 chlorophyll fluorescence

Acknowledgments

The authors acknowledge Drs. Kuo-Tan Li and Hiran Ariyawansa at National Taiwan University for providing the plant and the bacterial materials used in the study, respectively. Also, we thank Dr. Syuan-You Lin at National Chung Hsing University for providing thoughtful insights into interpreting the results of the work. This study was supported by a fund from National Taiwan University [NTU-112L9005].

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15592324.2024.2329842.

Additional information

Funding

The work was supported by the National Taiwan University [NTU-112L9005].