Khan Ghazanfar Abbas, Vogiatzaki Evangelia, Glauser Gaétan, Poirier Yves
Departof Lausanne, CH-1015 Lausanne, Switzerland (G.A.K., E.V., Y.P.); andNeuchâtel Platform of Analytical Chemistry, University of Neuchâtel, CH-2009 Neuchâtel, Switzerland (G.G.).
Departof Lausanne, CH-1015 Lausanne, Switzerland (G.A.K., E.V., Y.P.); andNeuchâtel Platform of Analytical Chemistry, University of Neuchâtel, CH-2009 Neuchâtel, Switzerland (G.G.)
Plant Physiol. 2016 May;171(1):632-44. doi: 10.1104/pp.16.00278. Epub 2016 Mar 25.
During their life cycle, plants are typically confronted by simultaneous biotic and abiotic stresses. Low inorganic phosphate (Pi) is one of the most common nutrient deficiencies limiting plant growth in natural and agricultural ecosystems, while insect herbivory accounts for major losses in plant productivity and impacts ecological and evolutionary changes in plant populations. Here, we report that plants experiencing Pi deficiency induce the jasmonic acid (JA) pathway and enhance their defense against insect herbivory. Pi-deficient Arabidopsis (Arabidopsis thaliana) showed enhanced synthesis of JA and the bioactive conjugate JA-isoleucine, as well as activation of the JA signaling pathway, in both shoots and roots of wild-type plants and in shoots of the Pi-deficient mutant pho1 The kinetics of the induction of the JA signaling pathway by Pi deficiency was influenced by PHOSPHATE STARVATION RESPONSE1, the main transcription factor regulating the expression of Pi starvation-induced genes. Phenotypes of the pho1 mutant typically associated with Pi deficiency, such as high shoot anthocyanin levels and poor shoot growth, were significantly attenuated by blocking the JA biosynthesis or signaling pathway. Wounded pho1 leaves hyperaccumulated JA/JA-isoleucine in comparison with the wild type. The pho1 mutant also showed an increased resistance against the generalist herbivore Spodoptera littoralis that was attenuated in JA biosynthesis and signaling mutants. Pi deficiency also triggered increased resistance to S. littoralis in wild-type Arabidopsis as well as tomato (Solanum lycopersicum) and Nicotiana benthamiana, revealing that the link between Pi deficiency and enhanced herbivory resistance is conserved in a diversity of plants, including crops.
在其生命周期中，植物通常会同时面临生物和非生物胁迫。低无机磷（Pi）是自然和农业生态系统中限制植物生长的最常见养分缺乏之一，而昆虫取食则导致植物生产力的重大损失，并影响植物种群的生态和进化变化。在此，我们报道，经历Pi缺乏的植物会诱导茉莉酸（JA）途径，并增强其对昆虫取食的防御能力。Pi缺乏的拟南芥（Arabidopsis thaliana）在野生型植物的地上部和根部以及Pi缺乏突变体pho1的地上部均表现出JA及其生物活性共轭物茉莉酸异亮氨酸的合成增强，以及JA信号通路的激活。Pi缺乏诱导JA信号通路的动力学受PHOSPHATE STARVATION RESPONSE1影响，PHOSPHATE STARVATION RESPONSE1是调节Pi饥饿诱导基因表达的主要转录因子。通过阻断JA生物合成或信号通路，pho1突变体通常与Pi缺乏相关的表型，如高地上部花青素水平和不良的地上部生长，会显著减弱。与野生型相比，受伤的pho1叶片中JA/茉莉酸异亮氨酸过度积累。pho1突变体还表现出对多食性食草动物斜纹夜蛾（Spodoptera littoralis）的抗性增加，而在JA生物合成和信号突变体中这种抗性会减弱。Pi缺乏也引发了野生型拟南芥以及番茄（Solanum lycopersicum）和本氏烟草（Nicotiana benthamiana）对斜纹夜蛾抗性的增加，这表明Pi缺乏与增强的食草动物抗性之间的联系在包括作物在内的多种植物中是保守的。
