Physiological characteristics (SDH and ALP activities) of arbuscular mycorrhizal colonization as affected by Bacillus thuringiensis inoculation under two phosphorus levels
Physiological characteristics (SDH and ALP activities) of arbuscular mycorrhizal colonization as affected by Bacillus thuringiensis inoculation under two phosphorus levels
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DOI：
10.1016/s0038-0717(03)00161-5
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发表时间：
2003-07
影响因子：
9.7
通讯作者：
A. Vivas;A. Marulanda;M. Gómez;J. Barea;R. Azcón
中科院分区：
文献类型：
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作者：
A. Vivas;A. Marulanda;M. Gómez;J. Barea;R. Azcón
苏云金芽孢杆菌（Bacillus thuringiensis（B.t.）在惰性无土基质中检测接种对植物生长以及对被Glomusmosseae或Glomusintraradices定殖的莴苣根的根内和根外菌根发育的影响。琥珀酸脱氢酶（SDH）和碱性磷酸酶（ALP）活性的组织化学测定表明活跃的真菌代谢进行了两个磷（P）水平。B. T的存在。无论P水平如何，丛枝菌根真菌（AMF）的根外和根内定殖增加[测量为频率（%F），强度（%I）和丛枝百分比（%A）]，而不是植物生长或营养。在最低施磷水平下，B.t.促进两种内生菌的根外和根内发育的程度相似，但G.根内定植植物[SDH：458%（M）和512%（A）; ALP：358%（M）和300%（A）]。P供应减少G.根内定殖率高于G.苔藓。然而，G.在P-改良培养基中发育的根内结构表现出根内或根外活性，而在G.结果表明，接种细菌可以补偿P对根内真菌生长和活力的负面影响。P修正降低幅度较大G.根内感染强度（非活体和活体染色）和G. mosseae活性（ALP染色）。因此，在最高P水平下，注意到每个内生菌在菌丝体中显示ALP活性的SDH活性感染的比例存在很大差异。植物的生理参数，如光合活性并没有解释具体的变化，对每个丛枝菌根真菌的影响P或B. t。接种。由于B. t.接种对G.根内定殖植物在最低磷条件下。在一般情况下，增加的代谢活性真菌生物量在共接种的植物是无关的P水平，是不相关的P植物吸收惰性无土基质。这些结果表明，细菌的影响增加AM内生菌的生理和代谢状态，这不仅证实，而且还扩展了以前的研究结果丛枝菌根-细菌的相互作用。本研究强调了根际自由生活细菌作为菌根辅助微生物的生态学和实践重要性。
The effect of Bacillus thuringiensis (B.t.) inoculation on plant growth and on the intra- and extraradical mycorrhizal development of lettuce roots colonized by Glomus mosseae or Glomus intraradices was examined in an inert, soil-less substrate. Histochemical determination of succinate dehydrogenase (SDH) and alkaline phosphatase (ALP) activities which indicate active fungal metabolism was carried out at two phosphorus (P) levels. The presence of B.t. increased extra- and intraradical colonization [measured as frequency (%F), intensity (%I) and percentage of arbuscules (%A)] for both arbuscular mycorrhizal fungi (AMF) rather than plant growth or nutrition regardless P level. Under the lowest level of P fertilization, B.t. enhanced to a similar extent the extra- and intraradical development of both endophytes, but the proportion of fungal tissue showing SDH or ALP was increased in G. intraradices-colonized plants. [SDH: 458% (M) and 512% (A); ALP: 358% (M) and 300% (A)]. P supply decreased G. intraradices colonization to a higher extent than G. mosseae. Nevertheless, the totality of G. intraradices structures developed in P-amended medium showed intraradical o extraradical activity, while in G. mosseae-colonized roots, SDH and ALP activities highly decreased relative to fungal tissue determined by TB staining as affected by P. Our results show that bacterial inoculation compensates the negative effect of P on the intraradical fungal growth and vitality. P amendment reduced in a higher extent G. intraradices infection intensity (non-vital and vital staining) and G. mosseae activity (ALP staining). Thus, big differences in the proportion of SDH-active infection showing ALP activity in mycelium developed by each endophyte were noted at the highest P level. Physiological plant parameters such as photosynthetic activity did not explain specific changes on each arbuscular-mycorrhizal fungus as affected by P or B.t. inoculation. The increased extraradical mycelium development and metabolic fungal activity as a result of B.t. inoculation positively affected N and P plant content and photosynthetic rate in G. intraradices-colonized plants under the lowest P conditions. In general, the increased metabolically active fungal biomass in co-inoculated plants was irrespective of P level and was not related to the P plant uptake from the inert soil-less substrate. These results show the bacterial effect increasing the physiological and metabolic status of AM endophytes, which not only confirms but also extends previous findings on arbuscular mycorrhizae-bacteria interactions. The present study emphasizes the ecological and practical importance of rhizosphere free-living bacteria as mycorrhizae-helper microorganisms.