*4.1. Plant Materials and Infection Methods*

*L. chinensis* bulbs were planted in the National Germplasm Bank of *Lycoris*, located in the Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing, China. The plants grow in conditions of 12 h/12 h day/night periods and 26 ◦C/18 ◦C day/night temperatures. The experiment was performed in March when the leaves were lush. The leaf tip injection method (Figure 1a) was used for bacterial infection, which makes it easier to infiltrate the whole leaf, showing more efficiency than the conventional leaf infiltration method (Figure 1b). After the infection was completed, the plant material was cultured in the dark at 18 ◦C for 2 d and then grown in a normal environment. After tip injection, when the leaves presented the chlorotic phenotype, the injected leaves and normal growing leaves were collected, labeled as treatment group (T) and control group (CK). All samples were immediately frozen in liquid nitrogen after collection and stored at −80 ◦C until RNA extraction. The collected leaves were used to analyze the expression of the *LcCLA1* and *LcPDS* genes.
