中科院昆明植物研究所与澳大利亚阿德莱德大学的科研人员合作，首次证实了丛枝菌根真菌对根寄生植物养分吸收器官的发生有直接显著的影响。相关成果近日发表在国际期刊《植物学纪事》上。
寄生植物和丛枝菌根（AM）真菌在陆地生态系统中广泛分布，两者均为陆地生态系统的重要组成部分。国内外关于这两类生物有过广泛而深入的研究，但多数情况下仅关注两者之一。
近期研究显示，AM真菌在宿主植物根部定殖的过程和根寄生植物对寄主植物的侵染过程可能具有相似的分子调控途径，两种生物过程有诸多相似之处。此外，逐步增多的研究表明，寄主植物根部的AM真菌定殖水平对寄生植物生长发育有显著影响。然而，由于多数寄生植物无法形成菌根，目前还没有关于寄生植物和AM真菌直接相互关系的研究报道。
为此，科研人员利用一种兼具AM定殖能力的根部兼性半寄生植物三色马先蒿，探讨了根寄生植物和AM真菌的直接互作关系。研究表明，接种AM真菌可强烈抑制寄生植物养分吸收器官（吸器）的发生，从而为寄生性杂草的生物防控提供了一条新思路。(生物谷：Bioon.com)
doi:10.1021/ja300475k
PMC:
PMID:
Inoculation with arbuscular mycorrhizal fungi suppresses initiation of haustoria in the root hemiparasite Pedicularis tricolor
Ai-Rong Li1,*, Sally E. Smith2, F. Andrew Smith2 and Kai-Yun Guan
Background and Aims Plant parasitism and arbuscular mycorrhizal (AM) associations have many parallels and share a number of regulatory pathways. Despite a rapid increase in investigations addressing the roles of AM fungi in regulating interactions between parasitic plants and their hosts, few studies have tested the effect of AM fungi on the initiation and differentiation of haustoria, the parasite-specific structures exclusively responsible for host attachment and nutrient transfer. In this study, we tested the influence of AM fungi on haustorium formation in a root hemiparasitic plant.
Methods Using a facultative root hemiparasitic species (Pedicularis tricolor) with the potential to form AM associations, the effects of inoculation were tested with two AM fungal species, Glomus mosseae and Glomus intraradices, on haustorium initiation in P. tricolor grown alone or with Hordeum vulgare ‘Fleet’ (barley) as the host plant. This study consisted of two greenhouse pot experiments.
Key Results Both AM fungal species dramatically suppressed intraspecific haustorium initiation in P. tricolor at a very low colonization level. The suppression over-rode inductive effects of the parasite's host plant on haustoria production and caused significant growth depression of P. tricolor.
Conclusions AM fungi had strong and direct suppressive effects on haustorium formation in the root hemiparasite. The significant role of AM fungi in haustorium initiation of parasitic plants was demonstrated for the first time. This study provides new clues for the regulation of haustorium formation and a route to development of new biocontrol strategies in management of parasitic weeds.
