Plant Science Group, Institute for Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
Ecological Sciences, The James Hutton Institute, Dundee, UK.
Plant Cell Environ. 2018 Oct;41(10):2357-2372. doi: 10.1111/pce.13350. Epub 2018 Jun 29.
Understanding the interactions between mineral nutrition and disease is essential for crop management. Our previous studies with Arabidopsis thaliana demonstrated that potassium (K) deprivation induced the biosynthesis of jasmonic acid (JA) and increased the plant's resistance to herbivorous insects. Here, we addressed the question of how tissue K affects the development of fungal pathogens and whether sensitivity of the pathogens to JA could play a role for the K-disease relationship in barley (Hordeum vulgare cv. Optic). We report that K-deprived barley plants showed increased leaf concentrations of JA and other oxylipins. Furthermore, a natural tip-to-base K-concentration gradient within leaves of K-sufficient plants was quantitatively mirrored by the transcript levels of JA-responsive genes. The local leaf tissue K concentrations affected the development of two economically important fungi in opposite ways, showing a positive correlation with powdery mildew (Blumeria graminis) and a negative correlation with leaf scald (Rhynchosporium commune) disease symptoms. B. graminis induced a JA response in the plant and was sensitive to methyl-JA treatment whereas R. commune initiated no JA response and was JA insensitive. Our study challenges the view that high K generally improves plant health and suggests that JA sensitivity of pathogens could be an important factor in determining the exact K-disease relationship.
了解矿物质营养与疾病之间的相互作用对于作物管理至关重要。我们之前在拟南芥中的研究表明，钾（K）缺乏会诱导茉莉酸（JA）的生物合成，并提高植物对草食性昆虫的抗性。在这里，我们探讨了组织 K 如何影响真菌病原体的发育，以及病原体对 JA 的敏感性是否在大麦（Hordeum vulgare cv. Optic）的 K-病关系中起作用。我们报告说，缺钾的大麦植物叶片中的 JA 和其他氧化脂的浓度增加。此外，在 K 充足的植物叶片中，JA 响应基因的转录水平定量反映了叶片中从顶部到底部的 K 浓度梯度。局部叶片组织 K 浓度以相反的方式影响两种具有经济重要性的真菌的发育，与白粉病（Blumeria graminis）呈正相关，与叶斑病（Rhynchosporium commune）呈负相关。B. graminis 在植物中诱导了 JA 反应，对甲基 JA 处理敏感，而 R. commune 没有引发 JA 反应，对 JA 不敏感。我们的研究挑战了高 K 通常会改善植物健康的观点，并表明病原体对 JA 的敏感性可能是决定确切 K-病关系的一个重要因素。
