Fig. 7: Functional analysis of the 159 bp CtLRR1 promoter insertion in pathogen defense.

a qRT-PCR analysis of LRR1 expression in seven tea accessions. Data are presented as mean ± SD (n = 3 biological replicates). Different lowercase letters indicate significant differences at P < 0.05 (one-way ANOVA with Waller–Duncan multiple-range test for post-hoc pairwise comparisons). Groups sharing the same letter are not significantly different. b Schematic representation of the SV in the LRR1 promoter. c PCR verification of the LRR1 promoter SVs in seven tea accessions. The experiment was independently repeated three times with similar results. d Diagram illustrating the dual-luciferase assay used to assess LRR1 promoter activity. e, f Luminescence imaging (e) and luciferase (LUC) activity quantification (f) show that compared with the expression of CsaLRR1 and CssLRR1, the transient expression of CtLRR1 in N. benthamiana leaves results in increased promoter activity. Relative LUC activity was normalized to REN activity. Empty represents the empty vector control. Data are presented as mean ± SD (n = 4 biological replicates). Different lowercase letters indicate significant differences at P < 0.05 (one-way ANOVA with Waller–Duncan multiple-range test for post-hoc pairwise comparisons). Groups sharing the same letter are not significantly different. g CK represents the tea leaves of C. sinensis cv. Longjin43 infected with Agrobacterium carrying empty pTRV1 and pTRV2 vectors, while VIGS represents the tea leaves infected with Agrobacterium carrying empty pTRV1 and pTRV2-CsLRR1. Chlorophyll fluorescence imaging shows infected leaves. Larger black areas indicate stronger pathogen infection severity. h CsLRR1 expression levels in control and silenced samples. Data are presented as mean ± SD (n = 5 biological replicates). i Lesion area measurements following C. gloeosporioides (Cg) infection in the control and VIGS-silenced groups (n = 40 per group). Box plots display median (center line), quartiles (box bounds), whiskers (1.5× IQR). Statistical significance was assessed using two-tailed Student’s t-tests. Source data are provided as a Source Data file.