Root hairs increase rhizosphere extension and carbon input to soil
Root hairs increase rhizosphere extension and carbon input to soil
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DOI：
10.1093/aob/mcx127
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发表时间：
2018-01-01
期刊：
影响因子：
4.2
通讯作者：
Carminati, Andrea
中科院分区：
文献类型：
--
作者：
Holz, Maire;Zarebanadkouki, Mohsen;Carminati, Andrea
背景和目的虽然人们普遍认为，根系分泌物增强植物根际微生物的相互作用，分泌物的空间分布的实验数据很少。我们的假设是，根毛分泌有机物质，扩大根际更远的根surface.Methods大麦（大麦'帕拉斯' -野生型）和它的根无毛突变体（brb）生长在根盒和标记（CO2）-C-14。将滤纸放置在土壤表面以捕获、成像和量化根分泌物。关键结果有根毛的植物将更多的碳（C）分配给根（野生型：13%; brb：同化C-14的8%）和根鞘（野生型：1.2%; brb：0.2%），而无毛植物将更多的C分配给芽（野生型：65%; brb：75%）。根毛增加了径向根际延伸的三倍，从0.5到1.5毫米。滤纸上的总分泌量为野生型植物的3倍以上相比，无毛mutant.Conclusion根毛增加分泌和空间根际延伸，这可能会提高根际相互作用和养分循环在较大的土壤体积。因此，根毛可能对营养限制条件下的植物有益。更大的C分配地下根毛的存在下，可以另外促进C封存。
Background and Aims Although it is commonly accepted that root exudation enhances plant-microbial interactions in the rhizosphere, experimental data on the spatial distribution of exudates are scarce. Our hypothesis was that root hairs exude organic substances to enlarge the rhizosphere farther from the root surface.Methods Barley (Hordeum vulgare 'Pallas' -wild type) and its root-hairless mutant (brb) were grown in rhizoboxes and labelled with (CO2)-C-14. A filter paper was placed on the soil surface to capture, image and quantify root exudates.Key Results Plants with root hairs allocated more carbon (C) to roots (wild type: 13 %; brb: 8 % of assimilated C-14) and to rhizosheaths (wild type: 1.2 %; brb: 0.2 %), while hairless plants allocated more C to shoots (wild type: 65 %; brb: 75 %). Root hairs increased the radial rhizosphere extension three-fold, from 0.5 to 1.5 mm. Total exudation on filter paper was three times greater for wild type plants compared to the hairless mutant.Conclusion Root hairs increase exudation and spatial rhizosphere extension, which probably enhance rhizosphere interactions and nutrient cycling in larger soil volumes. Root hairs may therefore be beneficial to plants under nutrient-limiting conditions. The greater C allocation below ground in the presence of root hairs may additionally foster C sequestration.