菌根真菌的碳氮循环功能研究进展

Progress of the function of mycorrhizal fungi in the cycle of carbon and nitrogen

摘要:

菌根(mycorrhiza)是土壤真菌与植物根系形成的共生体(symbiont), 真菌一方面从植物获取碳水化合物, 同时帮助植物吸收氮等矿质养分, 因此, 菌根真菌在生态系统的碳氮循环过程中发挥重要的作用。研究结果表明, 菌根真菌可利用约4%?26%的植物净光合固定的碳水化合物, 而其生物量和分泌物(如球囊霉素)具有重要的土壤碳汇功能; 同时菌根真菌可参与土壤复杂有机质的降解过程。在菌根共生体系中, 氮从根外菌丝到根内菌丝的传输经历了一个“无机-有机-无机”的转变过程。本文重点总结分析了菌根真菌在碳氮代谢功能与机理等方面的国内外最新研究进展, 以及目前存在的主要问题与未来的研究重点。

Abstract:

Mycorrhiza is a symbiotic association formed between soil fungi and plant roots. Mycorrhizal fungi exchange soil-derived nutrients for carbohydrates from host plants, and therefore play an important role in the cycle of carbon and nitrogen in ecosystems. Research results indicated that mycorrhizal fungi can obtain ca. 4%?26% of total net primary production of host plants, and biomass and secretion (glomalin) of mycorrhizal fungi are important soil carbon-pool. Simultaneously, mycorrhizal fungi may decompose the complex soil organic compounds. Nitrogen is transported from extraradical to intraradical hyphae by a transferring procedure from inorganic to organic and inorganic nitrogen in mycorrhizae. Advances of recent mycorrhizal researches on the metabolic function and mechanism of carbon and nitrogen were summarized and related fields in future studies were also mentioned in this review paper.