Chen Weili, Ye Tao, Sun Qinyu, Niu Tingting, Zhang Jiaxia
Tea Research Institute, Anhui Academy of Agricultural Sciences, Huangshan, China.
Front Plant Sci. 2023 Jan 16;13:1058092. doi: 10.3389/fpls.2022.1058092. eCollection 2022.
Tea has been gaining increasing popularity all over the world in recent years, and its yield and quality depend on the growth and development of tea plants [ (L.) Kuntze] in various environments. Nowadays, biotic stress and extreme weather, such as high temperature, drought, waterlogging, pests, and diseases, bring about much pressure on the production of tea with high quality. Wherein anthracnose, which is the most common and serious disease of tea plants, has earned more and more attention, as its control mainly relies on chemical pesticides. Arbuscular mycorrhizal fungi (AMF), forming symbiosis with most terrestrial plants, participate in plant resistance against the anthracnose disease, which was found by previous studies in a few herbaceous plants. However, there are a few studies about arbuscular mycorrhizal (AM) fungal regulation of the resistance to the anthracnose pathogen in woody plants so far. In this paper, we investigated the effect of AMF on the development of anthracnose caused by and tried to decipher the pertinent mechanism through transcriptome analysis. Results showed that inoculating AMF significantly reduced the damage of anthracnose on tea seedlings by reducing the lesion area by 35.29% compared to that of the control. The content of superoxide anion and activities of catalase and peroxidase significantly increased ( < 0.05) in mycorrhizal treatment in response to the pathogen with 1.23, 2.00, and 1.39 times higher, respectively, than those in the control. Pathways of plant hormone signal transduction, mitogen-activated protein kinase (MAPK) signaling, and phenylpropanoid biosynthesis might play roles in this regulation according to the transcriptomic results. Further redundancy analysis (RDA) and partial least squares structural equation modeling (PLS-SEM) analysis found that plant hormones, such as auxin and ethylene, and the antioxidant system (especially peroxidase) were of great importance in the AM fungal alleviation of anthracnose. Our results preliminarily indicated the mechanisms of enhanced resistance in mycorrhizal tea seedlings to the anthracnose pathogen and provided a theoretical foundation for the application of AMF as one of the biological control methods in tea plantations.
近年来，茶叶在全球范围内越来越受欢迎，其产量和品质取决于茶树[（L.）Kuntze]在各种环境中的生长发育情况。如今，生物胁迫和极端天气，如高温、干旱、涝灾、病虫害等，给高品质茶叶的生产带来了很大压力。其中，炭疽病是茶树最常见且最严重的病害，由于其防治主要依赖化学农药，因此越来越受到关注。丛枝菌根真菌（AMF）与大多数陆生植物形成共生关系，前人在一些草本植物上的研究发现其参与植物对炭疽病的抗性。然而，目前关于丛枝菌根（AM）真菌对木本植物炭疽病病原菌抗性调控的研究较少。本文研究了AMF对由[病原菌名称未给出]引起的炭疽病发展的影响，并试图通过转录组分析来解读相关机制。结果表明，接种AMF显著降低了炭疽病对茶苗的损害，与对照相比，病斑面积减少了35.29%。在菌根处理中，超氧阴离子含量以及过氧化氢酶和过氧化物酶的活性在响应病原菌时显著增加（P<0.05），分别比对照高1.23、2.00和1.39倍。根据转录组结果，植物激素信号转导途径、丝裂原活化蛋白激酶（MAPK）信号途径和苯丙烷生物合成途径可能在这种调控中发挥作用。进一步的冗余分析（RDA）和偏最小二乘结构方程模型（PLS-SEM）分析发现，生长素和乙烯等植物激素以及抗氧化系统（尤其是过氧化物酶）在AM真菌减轻炭疽病方面具有重要作用。我们的结果初步揭示了菌根化茶苗对炭疽病病原菌抗性增强的机制，并为AMF作为茶园生物防治方法之一的应用提供了理论基础。
