Skip to main content
. 2022 Sep 19;119(39):e2209717119. doi: 10.1073/pnas.2209717119

Fig. 1.

Fig. 1.

Expression analysis of CsHEC1 and phenotypic characterization of CsHEC1 knockout lines in cucumber. (A) Structure of cucumber fruit at the commercial harvest stage. Blue bracket, peduncle; red bracket, fruit neck; black bracket, fruit. (B) Variations in FNL (red brackets) in different cucumber germplasms. (C) The expression pattern of CsHEC1 in different parts of the ovary at 3 DBA. cff, corolla from the female flowers; fn, fruit neck; mid, middle. Values are means ± SD (n = 3). The red brackets indicate the fruit neck. (D–F) In situ hybridization analysis of CsHEC1 (D and E) or CsHEC2 (F) in cucumber. Longitudinal sections of developing flower primordium at stage 2 (D) and stage 6 (E and F). Asterisks indicate the developing fruit neck in cucumber. ca, carpel; fm, floral meristem; pe, petal; se, sepal; sta, stamen. (Scale bars, 100 µm.) (G and H) Tissue specificity of CsHEC1 expression was examined using the ProCsHEC1:GUS reporter system. GUS signals of CsHEC1 were highly enriched at the fruit neck and corolla of the female flower (G). Negative control showed no GUS signal (H). (Scale bars, 1 mm.) (I) Genotype identification of CsHEC1 knockout plants indicated the Cshec1#1 mutant with 9- and 4-bp deletions, and the Cshec1#2 mutant with a 2-bp deletion and 1-bp insertion. The stars represent the termination codon position and the yellow boxes indicate the bHLH domain. (J–L) Morphology of WT, Cshec1#1, and Cshec1#2 fruits at 0 DPP (J), 10 DPP (K), and 40 DPP (L). The red brackets indicate the fruit neck; the red and white double arrows represent the measured FNL and FL, respectively. (Scale bars, 2 cm.) (M and N) Quantification of FNL (M) and the ratio of FNL/FL (N) in WT and Cshec1 mutants at 40 DPP. Values are means ± SD (n = 10). (O and P) Representative cell morphology (O) and cell-length quantification (P) of longitudinal sections of the fruit necks in WT and Cshec1 fruits at 40 DPP. Values are means ± SD (n = 9). (Scale bar, 50 µm.) (Q) IAA content in the fruit necks of WT and Cshec1 mutants. FW, fresh weight. Values are means ± SD (n = 3). Significance analysis compared with WT was performed with the two-tailed Student’s t test (ns, no significant difference; **P < 0.01).