外生菌根对干旱胁迫的响应

从外生菌根真菌、外生菌根共生体以及外生菌根的间接作用等方面阐述外生菌根如何抵制干旱胁迫,并对未来我国外生菌根的研究提出了建议。干旱可以抑制外生菌根真菌的生长并降低其群落中真菌的多样性,干旱胁迫下外生菌根真菌子实体可以利用深度30cm以下的土壤水,子实体的表面积和体积比可作为筛选抗旱真菌的一个重要因子;在遭受干旱胁迫时,外生菌根共生体可以发生形态变化来应对干旱,同时增加了植株水分的吸收并改善了植物的光合作用、活性氧以及激素等相关代谢;外生菌根对植物生长的促进作用、增加土壤碳汇以及对其他根际微生物生长的促进作用等对宿主植物应对干旱胁迫有利。未来我国外生菌根研究应加强对干旱区优良菌-树组合的筛选工作,同时加大对乡土外生菌根真菌资源的调查力度,未来研究应重点向分子生物学领域推进。

Responses of ectomycorrhiza to drought stress: A review

This paper reviewed the research progress in the responses of ectomycorrhiza to drought stress and related resistance mechanisms from the aspects of ectomycorrhizal fungi,ectomycorrhizal symbiote,and indirect effects of ectomycorrhiza.The future research directions on the ectomycorrhiza in China were also prospected.Drought stress can inhibit the growth of ectomycorrhizal fungi,and decrease the fungal diversity in ectomycorrhizal fungal communities.Under drought stress,the ectomycorrhizal fungal sporocarp can use deep(>30 cm) soil water.The ratio of sporocarp surface to its volume is an important factor for the screening of drought-resistant strains of ectomycorrhizal fungi in arid region.Ectomycorrhizal symbiote can resist drought stress by morphological change,increasing water absorption,and improving related metabolisms such as the photosynthesis,reactive oxygen species,and hormones of plants.It would be beneficial for host plants to resist drought stress when the ectomycorrhiza promoted the growth of host plants and other rhizosphere microbes,and increased the soil carbon sink.It was suggested that the ectomycorrhizal research in China should focus on the screening of excellent fungi-tree combination in arid region,and pay more attention to the investigation of native ectomycorrhizal fungal resources.In the future research,an impetus should be made to the molecular biological research.