Currently, the control strategies of Botrytis cinerea mainly include chemical and biological methods, leading to environmental pollution and other problems. Ecological control involves suppressing the disease by regulating the facility environment. However, the infection process and the response mechanism of plants under different temperatures and humidity remain unclear. This study measured four cell wall–degrading enzymes, used light microscopy, scanning electron microscopy, and transmission electron microscopy to explore the impacts of temperature and humidity on the physiological and structural changes of the infection process and host response, and studied their interaction by correlation analysis. We observed that B. cinerea could cause infection due to undifferentiated hyphae under low humidity. The most severe infection was under the medium temperature and high humidity (MH) treatment, wherein the hyphae released cell wall–degrading enzymes to penetrate the host cells. Under high temperature, the mycelia grew without pathogenicity, while under low temperature, the gley time of the infection increased due to low-temperature stress. Additionally, we found that the structure of the infected host cells under different temperatures and humidity changed differently, including cell wall thickening, plasma membrane degradation, chloroplast disorganization, and starch granule anomalies. We also found that different temperatures and humidity had specific effects
