Identification of droopy leaves related gene, CsEXL3, in tea plant germplasm. (A) Representative leaves picture of tea plant germplasm with straight or droopy blade. Scale bar represents 5 cm. (B) The PF of selected germplasm with straight or droopy blade. Data shown represent the means ±SD of at least ten biological replicates. (C) The blade angle of selected germplasm with straight or droopy blade. (D) Lignin staining on cross-sections of the middle part in leaf blades midrib with phloroglucinol-HCl. The middle parts were selected on the direction from tip to the blade-stem boundary. The upper or lower unidirectional arrow indicates adaxial or abaxial sclerenchyma cells, respectively. Double arrow indicates the maximum length of vascular tissue. Scale bar represents 100 μm. (E) Diagram illustrating the adaxial sclerenchyma cells (Ads), abaxial sclerenchyma cells (Abs), and vascular bundle (V) in the leaf blades midrib of tea plant. (F) The maximum length of vascular tissue in the leaf blades midrib of selected germplasm. (G) The number of adaxial and abaxial sclerenchyma cells in the leaf blades midrib of selected germplasm. (H) Venn diagram showing the number of common differentially expressing genes (DEGs) in three type tissue of compared germplasms, JHZ49 and WS231. YA, the apical bud and first leaf; M1Y, first mature leaves; M2Y, second mature leaves. (I) Venn diagram showing the number of common genes between candidate genes from GWAS and DEGs of RNA-seq in WS231 and JHZ49. The common genes were divided into two groups, genes with FPKM≥10 and genes with FPKM<10. (J) The relative expression level of CsEXL3 in three type tissue of WS231 and JHZ49. **P < 0.01; *P < 0.05.