*2.9. qRT-PCR Analysis*

For expression analysis, we conducted qRT-PCR to investigate the expression pattern of five disease-resistant or defense-related genes for *P. capsici* resistance in pepper. Leaf samples were gathered from days 0, 1, 2, 3, 4, 5, 6, and 7 post inoculation with *P. capsici* in the resistant line "PI201234" and the susceptible line "Early calwonder." "Early calwonder" was defined as susceptible to three physiological races of *P. capsici*. Total RNAs were extracted utilizing the Plant RNA Kit (Tiangen DP441, China) as per the company's instructions. Subsequently, cDNAs were reverse-transcribed using TaKaRa Reverse Transcription Kit (Takara Biomedical Technology (Beijing) Co., Ltd., Beijing, China). Quantitative PCR was conducted on a 7500 Real-Time PCR System (Thermo Fisher Scientific, Waltham, MA, USA) using TB Green® Premix Ex TaqTM Kit (TaKaRa). The PCR program was as follows: Holding Stage Step 1: 95 ◦C 30 s, followed by 40 cycles of Step 1: 95 ◦C for 5 s, Step 2: 60 ◦C for 30 s, and 72 ◦C for 2 min. After the last cycle, the amplification was extended for 7 min at 72 ◦C. *AY572427* was used as internal control for qRT-PCR analysis. We employed the 2−ΔΔ<sup>T</sup> method to determine relative expression levels of candidate genes, which were normalized to that of actin gene *(AY572427).* Each target sample was analyzed using three biological replicates. All values were reported as the mean ± standard deviation (n = 3), and the statistical significance of any differences was analyzed using a Student's *t*-test.
