Phosphorus concentration coordinates a respiratory bypass, synthesis and exudation of citrate, and the expression of high-affinity phosphorus transporters in Solanum lycopersicum
Phosphorus concentration coordinates a respiratory bypass, synthesis and exudation of citrate, and the expression of high-affinity phosphorus transporters in Solanum lycopersicum
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DOI：
10.1111/pce.13155
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发表时间：
2018-04-01
影响因子：
7.3
通讯作者：
Ribas-Carbo, Miquel
中科院分区：
文献类型：
--
作者：
Fernandez Del-Saz, Nestor;Romero-Munar, Antonia;Ribas-Carbo, Miquel
植物表现出呼吸旁路（例如，交替氧化酶[AOX]），并增加其器官（叶和根）中羧酸盐的合成以响应磷（P）缺乏，这增加了P吸收能力。他们还表现出差异表达的高亲和力无机磷（Pi）转运蛋白，从而避免P毒性在高P availability. AOX和羧酸合成之间的关联进行了测试，在不同的土壤中生长的番茄植物P的可用性，通过使用植物生长在P-充足和P-限制条件下，并通过施加短期（24小时）P-充足的脉冲下生长的植物P限制。还进行了测试与植物定植丛枝菌根真菌，增加植物磷浓度降低磷的可用性。在体内AOX和细胞色素氧化酶的活性与羧酸的浓度和植物器官中的P浓度一起测量。还研究了Pi转运蛋白（LePT 1和LePT 2）的基因转录。植物磷浓度与这些性状之间的协调反应进行了观察，表明在土壤中足够的磷可利用性导致AOX活性和柠檬酸合成的抑制和编码高亲和力Pi转运蛋白的基因的转录下调，大概是为了避免磷毒性。
Plants exhibit respiratory bypasses (e.g., the alternative oxidase [AOX]) and increase the synthesis of carboxylates in their organs (leaves and roots) in response to phosphorus (P) deficiency, which increases P uptake capacity. They also show differential expression of high-affinity inorganic phosphorus (Pi) transporters, thus avoiding P toxicity at a high P availability.The association between AOX and carboxylate synthesis was tested in Solanum lycopersicum plants grown at different soil P availability, by using plants grown under P-sufficient and P-limiting conditions and by applying a short-term (24 hr) P-sufficient pulse to plants grown under P limitation. Tests were also performed with plants colonized with arbuscular mycorrhizal fungi, which increased plant P concentration under reduced P availability. The in vivo activities of AOX and cytochrome oxidase were measured together with the concentration of carboxylates and the P concentration in plant organs. Gene transcription of Pi transporters (LePT1 and LePT2) was also studied. A coordinated response between plant P concentration with these traits was observed, indicating that a sufficient P availability in soil led to a suppression of both AOX activity and synthesis of citrate and a downregulation of the transcription of genes encoding high-affinity Pi transporters, presumably to avoid P toxicity.