Leaf photosynthesis in different mycorrhizal types of woody plants and its associations with leaf characteristics and environmental factors

Abstract:

Leaf photosynthesis forms the foundation of plant energy and material cycles. Mycorrhizal fungi, as a crucial component associated with roots, play a significant role in regulating the nutrient absorption, water utilization, and stress resistance of plants and are key ecological factors affecting the function and stability of forest ecosystems. However, at present, knowledge is limited regarding the effects of different mycorrhizal types on the photosynthetic capacity of woody plants and their responses to environmental changes.Objective To explore the differences in photosynthetic capacity among woody plants with different mycorrhizal types and their responses to changes in leaf characteristics and environmental factors.Methods According to the China Plant Trait Database and available articles, we identified three mycorrhizal types of woody plants, which included arbuscular mycorrhiza (AM), ectomycorrhiza (ECM), and AM+ECM. On this foundation, a database of woody plant traits for different mycorrhizal types in China was established, with the data of each sample encompassing photosynthetic capacity, photosynthetic physiology, leaf structure, nutrient characteristics, and environmental factors.Results The woody plants with ECM had higher photosynthetic capacity than those with AM. Mycorrhizal types significantly influenced the relationship between leaf traits and photosynthetic capacity. The photosynthetic capacity of woody plants was primarily affected by the stomatal conductance and transpiration rate of leaves. In addition, the photosynthetic capacity of plants with AM were influenced by leaf area, specific leaf area (SLA), and nitrogen and phosphorous content. The photosynthetic capacity of plants with AM+ECM were affected by SLA, specific leaf weight, and carbon and phosphorous content, while that of plants with ECM was influenced by the vapor pressure deficit. The maximum net photosynthetic rate and maximum electron transport rate of plants with ECM were more susceptible to temperature and precipitation than plants with AM and AM+ECM.Conclusion Mycorrhizal types significantly affect the maximum net photosynthetic rate of woody plants, and leaf characteristics primarily influence the maximum net photosynthetic rate by regulating the maximum electron transport rate. Moreover, the effects of environmental factors on the morphological and physiological traits of woody plant leaves depend on mycorrhizal types.