Xing Mengyu, Sun Tao, Liu Tong, Jiang Zide, Xi Pinggen
Key Laboratory of Green Prevention and Control of Tropical Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
Department of Plant Pathology/Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
Microorganisms. 2024 Jan 17;12(1):184. doi: 10.3390/microorganisms12010184.
Litchi is a fruit of significant commercial value; however, its quality and yield are hindered by downy blight disease caused by . In this study, volatile organic compounds (VOCs) from TJGA-19 were investigated for their antifungal effects and studied in vitro and in planta for the suppression of litchi downy blight disease in litchi leaves and fruits. The growth of was inhibited by VOCs produced by TJGA-19 cultivated on autoclaved wheat seeds for durations of 10, 20, or 30 days. Volatiles from 20-day-old cultures were more active in inhibition effect against than those from 10- or 30-day-old cultures. These volatiles inhibit the growth of mycelia, sporulation, and oospore production, without any significant effect on sporangia germination. Additionally, the VOCs were effective in suppressing disease severity in detached litchi leaf and fruit infection assays. With the increase in the weight of the wheat seed culture of TJGA-19, the diameters of disease spots on leaves, as well as the incidence rate and disease indices on fruits, decreased significantly. Microscopic results from SEM and TEM investigations showed abnormal morphology of sporangia, mycelia, and sporangiophores, as well as organelle damage in caused by VOCs of TJGA-19. Spectroscopic analysis revealed the identification of 22 VOCs produced by TJGA-19, among which the most dominant compound was 2-Methyliborneol. These findings indicated the significant role of TJGA-19 compounds in the control of litchi downy blight disease and in improving fruit quality.
荔枝是一种具有重要商业价值的水果；然而，其品质和产量受到由[病原菌名称缺失]引起的霜霉病的阻碍。在本研究中，对TJGA - 19产生的挥发性有机化合物（VOCs）的抗真菌作用进行了研究，并在体外和植物体内研究了其对荔枝叶片和果实中荔枝霜霉病的抑制作用。在高压灭菌的小麦种子上培养10、20或30天的TJGA - 19产生的VOCs抑制了[病原菌名称缺失]的生长。培养20天的菌株产生的挥发物对[病原菌名称缺失]的抑制作用比培养10天或30天的菌株产生的挥发物更强。这些挥发物抑制菌丝体生长、孢子形成和卵孢子产生，对孢子囊萌发没有显著影响。此外，在离体荔枝叶片和果实感染试验中，VOCs能有效抑制病害严重程度。随着TJGA - 19小麦种子培养物重量增加, 叶片上病斑直径以及果实上的发病率和病情指数显著降低。扫描电子显微镜（SEM）和透射电子显微镜（TEM）研究的微观结果表明，TJGA - 19的VOCs导致[病原菌名称缺失]的孢子囊、菌丝体和孢子梗形态异常以及细胞器损伤。光谱分析鉴定出TJGA - 19产生的22种VOCs，其中最主要的化合物是2 - 甲基异冰片。这些发现表明TJGA - 19化合物在控制荔枝霜霉病和提高果实品质方面具有重要作用。
