Inoculation with Ericoid Mycorrhizal Associations Alleviates Drought Stress in Lowland and Upland Velvetleaf Blueberry (Vaccinium myrtilloides) Seedlings

Abstract

Although velvetleaf blueberry (Vaccinium myrtilloides) is usually associated with sandy (upland) areas of the North American boreal forest, lowland populations can be also found in bogs, suggesting possible adaptations to different site conditions. In this study, we examined the role of ericoid mycorrhizal (ERM) fungi in conferring drought resistance to the upland and lowland velvetleaf blueberry seedlings. The seedlings were inoculated with four ERM fungi (Pezicula ericae, Pezoloma ericae, Meliniomyces variabilis, and Oidiodendron maius) isolated from the roots of ericaceous plants and grown under controlled environmental conditions in sterilized soil. The inoculated and non-inoculated (inoculation control) plants were subsequently subjected to three cycles of drought stress by withdrawing watering. Lowland plants appeared to benefit relatively more from mycorrhizal colonization, compared with the upland plants, in terms of plant growth and drought survival. After three weeks of treatments, the dry weights of non-inoculated well-watered upland plants were higher compared to the non-inoculated lowland plants. However, these differences were offset by the inoculation of plants with ERM fungi, some of which also significantly improved drought resistance characteristics of the upland and lowland plants. There were no major differences in the effects of different ERM fungal species on drought responses of upland and lowland plants. Of the examined ericoid mycorrhizal fungi, inoculation with Pezicula ericae was the most effective in conferring drought resistance characteristics to both upland and lowland seedlings and helped maintain higher shoot water potentials, net photosynthetic, and transpiration rates in plants subjected to drought stress.

Mycorrhizas shape the evolution of plant adaptation to drought

“…Mycorrhizas are well known to influence the physiological capacity of plants to tolerate drought, with many studies documenting direct and indirect mechanisms, such as mycelial transport of water and nutrients, leading to beneficial effects on plant performance, including improved survival under drought (Augé, 2001; Lehto & Zwiazek, 2011; Sebastiana et al ., 2018; Mu et al ., 2021; Püschel et al ., 2021). This would indicate that mycorrhizas might accelerate the evolutionary gains of drought tolerance by enhancing the transgenerational success of mycorrhizal plants that survive repeated droughts, compared with that of the less successful non-mycorrhizal counterparts.…”

“…Furthermore, the ecto-, ericoid, and arbuscular mycorrhizas have in common the ability to influence the physiological capacity of their host plants to tolerate drought, while drought can also influence the development of these mycorrhizas (Augé, 2001;Lehto & Zwiazek, 2011;Sebastiana et al, 2018;Kilpeläinen et al, 2020;Mu et al, 2021;Püschel et al, 2021). A major gap of knowledge is still how plant adaptation to drought and mycorrhizas influence one another at an evolutionary time scale.…”

“…Despite these primary distinctions, the ecto- and ericoid mycorrhizas use a similar strategy for taking up nutrients, occupy niches with relatively similar characteristics, and even share some of the same fungal symbionts (Peat & Fitter, 1993; Van der Heijden et al ., 2015; Gerz et al ., 2018; Lu & Hedin, 2019). Furthermore, the ecto-, ericoid, and arbuscular mycorrhizas have in common the ability to influence the physiological capacity of their host plants to tolerate drought, while drought can also influence the development of these mycorrhizas (Augé, 2001; Lehto & Zwiazek, 2011; Sebastiana et al ., 2018; Kilpeläinen et al ., 2020; Mu et al ., 2021; Püschel et al ., 2021). A major gap of knowledge is still how plant adaptation to drought and mycorrhizas influence one another at an evolutionary time scale.…”

Changes and Correlation Between Physiological Characteristics of Rhododendron simsii and Soil Microbial Communities Under Heat Stress

“…Moreover, heat stress significantly reduced the availability of soil nutrient elements, leading to a reduction in plant biomass (Yeasmin et al, 2019). Mu et al (2021) reported that inoculation of ericoid mycorrhizae fungi can improve the heat and drought tolerance of plants and alleviate the damage of Rhododendron caused by heat stress. Therefore, plant growth and development under heat stress are closely related to soil nutrients, soil enzyme activities and other soil physicochemical properties, and soil microorganisms may also play an important role in the process of plant response to heat stress.…”

Lingonberry (Vaccinium vitis-idaea L.) Interact With Lachnum pygmaeum to Mitigate Drought and Promote Growth

“…The fungi associated with lingonberry are called Ericoid mycorrhizal (ErM) fungi ( Lukesova et al, 2015 ). ErM fungi are beneficial microorganisms for the growth of lingonberry, which can promote the growth and nutrient absorption of blueberry and reduce the damage to plants under drought, heavy metals, and saline-alkali environments ( Baba et al, 2021 ; Cai et al, 2021 ; Mu et al, 2021 ).…”