Kuper-Psenicnik Aisa, Bennett Jonathan A
Department of Plant Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5A8, Canada.
Mycorrhiza. 2024 Dec 13;35(1):3. doi: 10.1007/s00572-024-01175-3.
Plant partnerships with arbuscular mycorrhizal fungi (AMF) improve plant resilience to stress by increasing the plant's access to and uptake of essential nutrients and water, as well as regulating the plant's stress response. The magnitude and direction of AMF effects during the relationship depend on multiple factors including plant identity and environmental context. To investigate how AMF influence plant responses to environmental stresses, we assessed the effects of drought and salinity on growth, final biomass, and reproduction of nine alfalfa (Medicago sativa) cultivars inoculated with Rhizophagus irregularis or grown alone. In absence of stress, the fungus increased nutrient content, but caused declines in biomass through a reduction in initial growth that was not overcome by a later growth spurt. Mycorrhizal fungus inoculation also magnified stress effects on growth in most scenarios, but this depended on the stress type and cultivar. For salinity, this stress increase in inoculated plants was mediated by increased salt accumulation. Flowering of each cultivar was affected by both inoculation and stress type, albeit erratically, whereas seed production was only affected by inoculation when drought stressed. We found no clear pattern distinguishing differences in mycorrhizal fungus effects on stress among cultivars; however, our results show that mycorrhizal fungus effects on plant stress responses are contingent on the plant performance metric and stress type, highlighting the complexity of responses to mycorrhizas.
植物与丛枝菌根真菌（AMF）的共生关系通过增加植物对必需养分和水分的获取与吸收，以及调节植物的应激反应，提高了植物对胁迫的抵御能力。在这种共生关系中，AMF影响的程度和方向取决于多种因素，包括植物种类和环境背景。为了研究AMF如何影响植物对环境胁迫的反应，我们评估了干旱和盐度对接种了不规则球囊霉或单独生长的9个苜蓿（紫花苜蓿）品种的生长、最终生物量和繁殖的影响。在没有胁迫的情况下，真菌增加了养分含量，但通过降低初始生长导致生物量下降，后期的生长激增也未能克服这一影响。在大多数情况下，接种菌根真菌也放大了胁迫对生长的影响，但这取决于胁迫类型和品种。对于盐度，接种植物中这种胁迫的增加是由盐分积累增加介导的。每个品种的开花都受到接种和胁迫类型的影响，尽管情况不稳定，而种子产量仅在干旱胁迫时受到接种的影响。我们没有发现区分不同品种间菌根真菌对胁迫影响差异的明确模式；然而，我们的结果表明，菌根真菌对植物应激反应的影响取决于植物性能指标和胁迫类型，突出了对菌根反应的复杂性。
