College of Forestry, Shenyang Agricultural University, Shenyang, China.
Henan Province Key Laboratory of Efficient Crop Production and Food Quality Safety, Modern Agricultural Industry Research Institute of Henan Zhoukou National Agricultural High-tech Industry Demonstration Zone, Zhoukou Normal University, Zhoukou, China.
Physiol Plant. 2024 Sep-Oct;176(5):e14556. doi: 10.1111/ppl.14556.
Nigrospora oryzae, a newly identified pathogen, is responsible for poplar leaf blight, causing significant harm to poplar growth. Here, we describe, for the first time, a biological control method for the control of poplar leaf blight via the applications of 3 dominant Trichoderma strains/species. In this study, dominant Trichoderma species/strains with the potential for biocontrol were identified and then further characterised via dual culture assays, volatile organic compounds (VOCs), and culture filtrates. The biocontrol efficacy of these strains against N. oryzae was found to exceed 60%. Furthermore, the reactive oxygen species (ROS) content in Populus davidiana × P. alba var. pyramidalis (PdPap) leaves pretreated with these Trichoderma strains significantly decreased. Furthermore, pretreatment of PdPap with a combination of these Trichoderma (Tcom) resulted in 9.71-fold and 1.95-fold increases in peroxidase (POD) and superoxide dismutase (SOD) activity, respectively, and 3.87-fold decrease in the MDA content compared to controls. Moreover, Tcom pretreatment activated the salicylic acid (SA) and jasmonic acid (JA) pathway-dependent defence responses of poplar, upregulating pathogenesis-related protein (PR) and MYC proto-oncogene (MYC-R) by more than 12-fold and 17.32-fold, respectively. In addition, Trichoderma treatments significantly increased the number of lateral roots, aboveground biomass, and stomata number and density of PdPap, and Tcom was superior to the single pretreatments. The soil pH also became weakly acidic in these pretreatments, which is beneficial for the growth of PdPap seedlings. These findings indicate that these dominant Trichoderma strains can effectively increase biocontrol and poplar growth promotion.
新鉴定的病原菌稻绿核菌引起杨树叶枯病，对杨树生长造成严重危害。本研究首次描述了利用 3 种优势木霉（Trichoderma）菌株/种防治杨树叶枯病的生物防治方法。本研究通过对峙培养试验、挥发性有机化合物（VOC）和培养滤液进一步鉴定和表征了具有生防潜力的优势木霉种/菌株。这些菌株对稻绿核菌的防治效果超过 60%。此外，用这些木霉菌株预处理后的银腺杨×山杨杂种（Populus davidiana×P.alba var.pyramidalis，PdPap）叶片中的活性氧（ROS）含量显著降低。此外，用这些木霉（Tcom）的组合预处理 PdPap 可使过氧化物酶（POD）和超氧化物歧化酶（SOD）的活性分别提高 9.71 倍和 1.95 倍，丙二醛（MDA）的含量降低 3.87 倍，与对照相比。此外，Tcom 预处理激活了杨树水杨酸（SA）和茉莉酸（JA）途径依赖的防御反应，使病程相关蛋白（PR）和 MYC 原癌基因（MYC-R）的表达分别上调了 12 倍和 17.32 倍。此外，木霉处理显著增加了银腺杨×山杨杂种的侧根数、地上生物量和气孔数和密度，且 Tcom 优于单一预处理。这些预处理还使土壤 pH 值呈弱酸性，有利于 PdPap 幼苗的生长。这些发现表明，这些优势木霉菌株可有效提高生物防治和杨树生长促进效果。
