Yang Demei, Luo Jiangli, Zhou Ying, Zhou Sixuan, Liu Xiongwei, Liu Chang
School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, China.
Institute of Animal Husbandry and Veterinary Sciences of Guizhou Province, Guiyang, China.
PeerJ. 2025 Mar 24;13:e19130. doi: 10.7717/peerj.19130. eCollection 2025.
Sooty blotch, a primary leaf disease affecting (Thunb.) A.DC. (, AC), significantly impacts both the yield and quality of this medicinal plant. However, the specific species of pathogenic fungi responsible for this disease and their mechanisms of pathogenesis remain unclear. To elucidate the etiology of sooty blotch, it is essential to investigate effective prevention and treatment methods, and provide a theoretical basis for the effective protection of AC. Initially, the alterations in internal organelles that result in sooty blotch were examined using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Additionally, differential genes were analyzed using differential display reverse transcriptase-PCR (DDRT-PCR) in both healthy and diseased leaves of AC. Moreover, the pathogenic fungi were separated, purified and identified from leaves infected with sooty blotch of AC, and subsequently, their pathogenicity and biological characteristics were tested. Furthermore, the inhibitory effect of pathogens was measured using the water extract of traditional Chinese medicine, based on the growth rate of the mycelium. The findings indicated that the photosynthesis rate of diseased leaves was slower than that of healthy leaves, as revealed by TEM and SEM analyses. Additionally, DDRT-PCR results demonstrated that the differentially expressed genes primarily included those related to zinc finger proteins, acyl-CoA-transferases, and chloroplasts. The phylogenetic tree and pathogenicity test results showed that the pathogens causing sooty blotch of AC were and . Microscopic observation revealed that and exhibited distinct microscopic characteristics, and a pH range of 7-10 along with a subdued light environment were more conducive to the growth of pathogens. Additionally, the water extract of Hsu et S. C. Cheng and (Thunb.) A.DC. had a strong antifungal action on the two pathogens of sooty blotch, and the water extract of Ardisia crenate Sims had a better antifungal action on the . In this study, and were reported as pathogenic fungi causing sooty blotch for the first time, and affected the photosynthesis of AC leaf, and these study provides a theoretical basis for the diagnosis and prevention of (Thunb.) A.DC. sooty blotch.
煤烟病是一种影响（Thunb.）A.DC.（，AC）的主要叶片病害，对这种药用植物的产量和质量都有显著影响。然而，导致这种病害的致病真菌的具体种类及其致病机制仍不清楚。为了阐明煤烟病的病因，有必要研究有效的防治方法，并为AC的有效保护提供理论依据。首先，使用透射电子显微镜（TEM）和扫描电子显微镜（SEM）检查导致煤烟病的内部细胞器变化。此外，在AC的健康叶片和患病叶片中使用差异显示逆转录聚合酶链反应（DDRT-PCR）分析差异基因。此外，从感染AC煤烟病的叶片中分离、纯化和鉴定致病真菌，随后测试它们的致病性和生物学特性。此外，根据菌丝体的生长速率，使用中药水提取物测量病原体的抑制作用。结果表明，通过TEM和SEM分析发现，患病叶片的光合速率比健康叶片慢。此外，DDRT-PCR结果表明，差异表达基因主要包括与锌指蛋白、酰基辅酶A转移酶和叶绿体相关的基因。系统发育树和致病性测试结果表明，导致AC煤烟病的病原体是和。显微镜观察表明，和表现出明显的微观特征，pH值在7-10范围内以及弱光环境更有利于病原体的生长。此外，Hsu et S.C.Cheng和（Thunb.）A.DC.的水提取物对煤烟病的两种病原体具有很强的抗真菌作用，而朱砂根的水提取物对具有更好的抗真菌作用。在本研究中，和首次被报道为导致煤烟病的致病真菌，并影响AC叶片的光合作用，这些研究为（Thunb.）A.DC.煤烟病的诊断和防治提供了理论依据。
