National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, University of CAS, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
School of Life Science and Technology, ShanghaiTech University, Shanghai 200031, People's Republic of China.
Nat Commun. 2017 Jan 9;8:13925. doi: 10.1038/ncomms13925.
Immunity deteriorates with age in animals but comparatively little is known about the temporal regulation of plant resistance to herbivores. The phytohormone jasmonate (JA) is a key regulator of plant insect defense. Here, we show that the JA response decays progressively in Arabidopsis. We show that this decay is regulated by the miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE9 (SPL9) group of proteins, which can interact with JA ZIM-domain (JAZ) proteins, including JAZ3. As SPL9 levels gradually increase, JAZ3 accumulates and the JA response is attenuated. We provide evidence that this pathway contributes to insect resistance in young plants. Interestingly however, despite the decay in JA response, older plants are still comparatively more resistant to both the lepidopteran generalist Helicoverpa armigera and the specialist Plutella xylostella, along with increased accumulation of glucosinolates. We propose a model whereby constitutive accumulation of defense compounds plays a role in compensating for age-related JA-response attenuation during plant maturation.
动物的免疫力随着年龄的增长而下降，但对于植物对食草动物的抗性的时间调节却知之甚少。植物激素茉莉酸（JA）是植物昆虫防御的关键调节剂。在这里，我们表明拟南芥中的 JA 反应逐渐衰减。我们表明，这种衰减受 miR156 靶向 SQUAMOSA PROMOTER BINDING PROTEIN-LIKE9（SPL9）蛋白组的调节，该蛋白组可以与 JA ZIM 结构域（JAZ）蛋白相互作用，包括 JAZ3。随着 SPL9 水平的逐渐增加，JAZ3 积累，JA 反应减弱。我们提供的证据表明，该途径有助于年轻植物对昆虫的抗性。然而，有趣的是，尽管 JA 反应下降，但与拟南芥相比，年老的植物对鳞翅目一般害虫烟粉虱和小菜蛾仍然具有更高的抗性，同时积累更多的硫代葡萄糖苷。我们提出了一个模型，即在植物成熟过程中，防御化合物的组成性积累在补偿与年龄相关的 JA 反应衰减方面发挥作用。
