Centro de Investigaciones sobre Desertificación (CSIC/ UV/GV), Camí de la Marjal s/n, 46470 Albal (Valencia), Spain.
Mycologia. 2004 May-Jun;96(3):452-62.
A new in vitro experimental system was developed to study the morphogenesis of discrete regions of a single extraradical mycelium of the arbuscular mycorrhizal (AM) fungus Glomus intraradices, growing simultaneously in six different agar-based media. The media were (i) unamended water agar (WA), (ii) WA+PO(4)(3-) (PO(4)(3-)), (iii) WA+NO(3)(-) (NO(3)(-)), (iv) WA+NH(4)(+) (NH(4)(+)), (v) WA+NH(4)(+)+MES (NH(4)(+)+MES) and (vi) minimal medium (M, complete nutrients). Each medium was amended with the pH indicator bromocresol purple. The extraradical mycelium of the fungus showed between-treatment differences in morphogenesis, architecture, formation of branched absorbing structures (BAS) and sporulation. Extraradical hyphae that developed in WA or PO(4)(3-) compartments exhibited an economic development pattern, in which runner hyphae radially extended the external colony. Extraradical hyphal growth in the NO(3)(-) compartments was characterized by increased formation of runner hyphae, BAS and spores and an alkalinization of the medium. In the two NH(4)(+)-amended media (NH(4)(+), NH(4)(+)+MES), sporulation was suppressed and considerable morphological changes were noted. These results show the plasticity of G. intraradices that lets it efficiently exploit an heterogeneous substrate.
建立了一个新的体外实验系统，用于研究单个丛枝菌根（AM）真菌 Glomus intraradices 的一个单独的根外菌丝的不同区域的形态发生，同时在六种不同的基于琼脂的培养基中生长。这些培养基是（i）未添加水琼脂（WA），（ii）WA+PO （3-）（PO （3-）），（iii）WA+NO （3-）（NO （3-）），（iv）WA+NH （4+）（NH （4+）），（v）WA+NH （4+）+MES（NH （4+）+MES）和（vi）最小培养基（M，完整养分）。每个培养基都添加了 pH 指示剂溴甲酚紫。真菌的根外菌丝在形态发生、结构、分支吸收结构（BAS）形成和孢子形成方面表现出处理间差异。在 WA 或 PO （3-）隔室中发育的根外菌丝表现出经济发展模式，其中 runner 菌丝径向扩展外部菌落。在 NO （3-）隔室中根外菌丝的生长以增加 runner 菌丝、BAS 和孢子的形成以及培养基的碱化特征。在两种添加 NH （4+）的培养基（NH （4+），NH （4+）+MES）中，孢子形成受到抑制，并观察到相当大的形态变化。这些结果表明 G. intraradices 的可塑性使其能够有效地利用异质基质。
