Development of specific rhizosphere bacterial communities in relation to plant species, nutrition and soil type
Development of specific rhizosphere bacterial communities in relation to plant species, nutrition and soil type
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DOI：
10.1023/b:plso.0000035569.80747.c5
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发表时间：
2004-04-01
期刊：
影响因子：
4.9
通讯作者：
Yang, CH
中科院分区：
文献类型：
--
作者：
Marschner, P;Crowley, D;Yang, CH
根际微生物群落对植物营养和健康具有重要意义。采用16S rDNA PCR-DGGE非培养法进行群落分析，研究了pH、土壤类型、土壤改型、植物营养状况、植物种类和植物年龄等因素对根际细菌群落结构的影响。同时，对不同根区位置细菌群落的空间变异性进行了评价。结果表明，细菌群落结构受土壤pH值和施磷方式的影响。黄瓜和大麦在缺氮或缺磷土壤中短期（15 ~ 22 d）生长，根际细菌群落结构受土壤类型和施肥的影响，但不受植物种类的影响。通过对鹰嘴豆、油菜籽和苏丹草3种植物在3种不同土壤（砂、壤土和粘土）上生长的7.5周试验，土壤和植物之间复杂的相互作用对根际群落的影响是明显的。在沙地和壤土中，三种植物的根际群落结构明显不同，而在粘土中，油菜和苏丹草的根际群落结构与鹰嘴豆相似，但存在差异。在所有土壤中，根尖的根际群落结构与成熟根区不同。在白豆中，非簇根的细菌群落结构与簇根的不同。随着植株成熟，不同根龄级（幼、成熟、老）的根际群落明显不同。我们的结论是，许多不同的因素将有助于形成根际的物种组成，但植物本身发挥高度选择性的作用，至少与土壤的作用一样大。根系分泌物的数量和组成是影响群落结构差异的关键因素。
Rhizosphere microbial communities are important for plant nutrition and plant health. Using the culture-independent method of PCR-DGGE of 16S rDNA for community analyses, we conducted several experiments to investigate the importance of pH, soil type, soil amendment, nutritional status of the plant, plant species and plant age on the structure of the bacterial community in the rhizosphere. At the same time, we assessed the spatial variability of bacterial communities in different root zone locations. Our results showed that the bacterial community structure is influenced by soil pH and type of P fertilization. In a short-term experiment ( 15 - 22 days) with cucumber and barley growing in a N deficient or a P deficient soil, the bacterial community structure in the rhizosphere was affected by soil type and fertilization but not by plant species. In a 7.5-week experiment with three plant species ( chickpea, canola, Sudan grass) growing in three different soils ( a sand, a loam and a clay), the complex interactions between soil and plant effects on the rhizosphere community were apparent. In the sand and the loam, the three plant species had distinct rhizosphere communities while in the clay soil the rhizosphere community structures of canola and Sudan grass were similar and differed from those of chickpea. In all soils, the rhizosphere community structures of the root tip were different from those in the mature root zone. In white lupin, the bacterial community structure of the non-cluster roots differed from those of the cluster roots. As plants matured, different cluster root age classes ( young, mature, old) had distinct rhizosphere communities. We conclude that many different factors will contribute to shaping the species composition in the rhizosphere, but that the plant itself exerts a highly selective effect that is at least as great as that of the soil. Root exudate amount and composition are the key drivers for the differences in community structure observed in this study.