Phosphate excess increases susceptibility to pathogen infection in rice
Phosphate excess increases susceptibility to pathogen infection in rice
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DOI：
10.1111/mpp.12916
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发表时间：
2020-02-19
影响因子：
4.9
通讯作者：
San Segundo, Blanca
中科院分区：
文献类型：
--
作者：
Campos-Soriano, Lidia;Bundo, Mireia;San Segundo, Blanca
磷是植物生长和生产力所必需的营养物质。然而，由于土壤固定，土壤中的磷有效性很少足以维持作物的高产。过度使用化肥以规避磷酸盐(PI)有限的生物有效性，导致了农业土壤中土壤磷超标的情况。虽然植物对磷缺乏的适应性反应已经得到了深入的研究，但对植物如何适应磷过量以及磷过量如何影响抗病能力的了解较少。我们发现，高磷受精和随后的磷积累，提高了水稻对稻瘟病菌侵染的敏感性。这种真菌是稻瘟病的病原体，稻瘟病是全世界栽培水稻最具破坏性的疾病之一。同样，MIR399f的过表达导致水稻叶片中PI含量的增加，从而增强了对稻瘟病菌的敏感性。在病原菌侵染过程中，水稻植株中防御相关基因的激活较弱，叶片中过量积累PI，这与观察到的稻瘟病感病表型一致。这些数据支持，当PI过量时，会损害水稻的防御机制，同时证明miR399作为水稻免疫的负调控因子发挥作用。在控制抗病方面，PI信号和防御信号这两条信号通路必须以协调的方式运行。这些信息为了解水稻植株在高磷条件下免疫的分子机制提供了基础，这是水稻稻瘟病防治中应考虑的一个方面。
Phosphorus (P) is an essential nutrient for plant growth and productivity. Due to soil fixation, however, phosphorus availability in soil is rarely sufficient to sustain high crop yields. The overuse of fertilizers to circumvent the limited bioavailability of phosphate (Pi) has led to a scenario of excessive soil P in agricultural soils. Whereas adaptive responses to Pi deficiency have been deeply studied, less is known about how plants adapt to Pi excess and how Pi excess might affect disease resistance. We show that high Pi fertilization, and subsequent Pi accumulation, enhances susceptibility to infection by the fungal pathogen Magnaporthe oryzae in rice. This fungus is the causal agent of the blast disease, one of the most damaging diseases of cultivated rice worldwide. Equally, MIR399f overexpression causes an increase in Pi content in rice leaves, which results in enhanced susceptibility to M. oryzae. During pathogen infection, a weaker activation of defence-related genes occurs in rice plants over-accumulating Pi in leaves, which is in agreement with the phenotype of blast susceptibility observed in these plants. These data support that Pi, when in excess, compromises defence mechanisms in rice while demonstrating that miR399 functions as a negative regulator of rice immunity. The two signalling pathways, Pi signalling and defence signalling, must operate in a coordinated manner in controlling disease resistance. This information provides a basis to understand the molecular mechanisms involved in immunity in rice plants under high Pi fertilization, an aspect that should be considered in management of the rice blast disease.