Multiple impacts of the plant growth-promoting rhizobacterium Variovorax paradoxus 5C-2 on nutrient and ABA relations of Pisum sativum.
Multiple impacts of the plant growth-promoting rhizobacterium Variovorax paradoxus 5C-2 on nutrient and ABA relations of Pisum sativum.
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DOI：
10.1093/jxb/ers301
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发表时间：
2012-11
影响因子：
6.9
通讯作者：
Dodd IC
中科院分区：
文献类型：
--
作者：
Jiang F;Chen L;Belimov AA;Shaposhnikov AI;Gong F;Meng X;Hartung W;Jeschke DW;Davies WJ;Dodd IC
解决根际细菌促进植物生长的生理机制是困难的，因为许多这样的细菌含有多种植物生长促进特性。为了进一步了解含ACC脱氨酶（ACCd）的根际细菌Variovorax paradoxus 5C-2对植物生长的影响，研究了根际细菌接种对豌豆（Pisum sativum）矿质营养和脱落酸（阿坝）的流动和分配以及阿坝代谢的影响。虽然根构型不受影响，接种增加根和地上部的生物量，气孔导度，分别为20，15和24%，增加氮，磷，钾，钙，镁的吸收分别为16，81，50，46和58%，分别。接种植物根系中的P沉积量是未接种对照的4.9倍。根际细菌接种增加根到地上部木质部流量和地上部到根韧皮部流量的K分别为1.8和2.1倍。在对照植物中，钾沉积的主要汇是根和上部拍摄（总吸收量的43%和49%，分别），而根际细菌接种增加K分配到下部拍摄的其他舱室（木质部，韧皮部，上部拍摄）的费用。尽管在体外不能代谢阿坝，但V. paradoxus 5C-2使根阿坝浓度和积累降低了40- 60%。虽然接种减少木质部阿坝流量，韧皮部阿坝流量增加。是否细菌ACCd衰减根到芽阿坝信号需要进一步调查，因为阿坝是至关重要的干旱植物的生长，和ACCd含有生物体已被提倡作为一种手段，最大限度地减少植物在干燥土壤中的生长抑制。
Resolving the physiological mechanisms by which rhizobacteria enhance plant growth is difficult, since many such bacteria contain multiple plant growth-promoting properties. To understand further how the 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCd)-containing rhizobacterium Variovorax paradoxus 5C-2 affects plant growth, the flows and partitioning of mineral nutrients and abscisic acid (ABA) and ABA metabolism were studied in pea (Pisum sativum) plants following rhizosphere bacterial inoculation. Although root architecture was not affected, inoculation increased root and shoot biomass, and stomatal conductance, by 20, 15, and 24%, respectively, and increased N, P, K, Ca, and Mg uptake by 16, 81, 50, 46, and 58%, respectively. P deposition in inoculated plant roots was 4.9 times higher than that in uninoculated controls. Rhizobacterial inoculation increased root to shoot xylem flows and shoot to root phloem flows of K by 1.8- and 2.1-fold, respectively. In control plants, major sinks for K deposition were the roots and upper shoot (43% and 49% of total uptake, respectively), while rhizobacterial inoculation increased K distribution to the lower shoot at the expense of other compartments (xylem, phloem, and upper shoot). Despite being unable to metabolize ABA in vitro, V. paradoxus 5C-2 decreased root ABA concentrations and accumulation by 40–60%. Although inoculation decreased xylem ABA flows, phloem ABA flows increased. Whether bacterial ACCd attenuates root to shoot ABA signalling requires further investigation, since ABA is critical to maintain growth of droughted plants, and ACCd-containing organisms have been advocated as a means of minimizing growth inhibition of plants in drying soil.