Casassola Alice, Brammer Sandra P, Chaves Márcia S, Martinelli José A, Stefanato Francesca, Boyd Lesley A
Agronomy Post-Graduate Program, University of Passo Fundo, BR285, Passo Fundo, Rio Grande do Sul 99052900, Brazil.
Department of Biotechnology and Phytophatology, Brazilian Agricultural Research Corporation, BR285, Km294, Passo Fundo, Rio Grande do Sul 99001970, Brazil.
Physiol Mol Plant Pathol. 2015 Jan;89:49-54. doi: 10.1016/j.pmpp.2014.12.004.
Leaf rust, caused by the foliar pathogen is a major disease of wheat in the southern region of Brazil and invariably impacts on production, being responsible for high yield losses. The Brazilian wheat cultivar Toropi has proven, durable adult plant resistance (APR) to leaf rust, which uniquely shows a pre-haustorial resistance phenotype. In this study we aimed to understand the interaction between and the pre-haustorial APR in Toropi by quantitatively evaluating the temporal transcription profiles of selected genes known to be related to infection and defense in wheat. The expression profiles of 15 selected genes varied over time, grouping into six expression profile groups. The expression profiles indicated the induction of classical defence pathways in response to pathogen development, but also the potential modification of Toropi's cellular status for the benefit of the pathogen. Classical defence genes, including peroxidases, β-1,3-glucanases and an endochitinase were expressed both early (pre-haustorial) and late (post-haustorial) over the 72 h infection time course, while induction of transcription of other infection-related genes with a potential role in defence, although variable was maintained through-out. These genes directly or indirectly had a role in plant lignification, oxidative stress, the regulation of energy supply, water and lipid transport, and cell cycle regulation. The early induction of transcription of defence-related genes supports the pre-haustorial resistance phenotype in Toropi, providing a valuable source of genes controlling leaf rust resistance for wheat breeding.
叶锈病由叶部病原菌引起，是巴西南部地区小麦的一种主要病害，始终会影响产量，导致高产损失。巴西小麦品种托罗皮已被证明对叶锈病具有持久的成株抗性（APR），这种抗性独特地表现出吸器前抗性表型。在本研究中，我们旨在通过定量评估已知与小麦感染和防御相关的选定基因的时间转录谱，来了解托罗皮中病原菌与吸器前APR之间的相互作用。15个选定基因的表达谱随时间变化，分为六个表达谱组。表达谱表明，响应病原菌发育，经典防御途径被诱导，但也表明托罗皮的细胞状态可能为病原菌的利益而发生改变。经典防御基因，包括过氧化物酶、β-1,3-葡聚糖酶和一种内切几丁质酶，在72小时感染时间进程中，在早期（吸器前）和晚期（吸器后）均有表达，而其他与感染相关的基因，尽管其转录诱导情况各异，但在整个过程中都保持有潜在的防御作用。这些基因直接或间接地在植物木质化、氧化应激、能量供应调节、水和脂质运输以及细胞周期调节中发挥作用。防御相关基因转录的早期诱导支持了托罗皮的吸器前抗性表型，为小麦育种提供了控制叶锈病抗性的宝贵基因来源。
