Figure 3.

HTB Regulates Fruit Growth via Fine-Tuning Auxin Homeostasis

(A and B) Auxin signaling visualized by pDR5v2:GUS in stage-14 fruits of WT (A) and htb-1 (B).

(C and D) Measurements of IPA (C) and IAA (D) in fruit shoulders of WT and htb-1 in stage-14 fruits.

(E–H) Expression of CrTAA1 and CrYUC9 shown by GUS staining of the pCrTAA1:GUS and pCrYUC9:GUS reporter lines at developmental stage 14 in WT (E and G) and htb-1 (F and H).

(I and J) Expression analysis of CrTAA1 (I) and CrYUC9 (J) in fruit shoulders of WT, htb-1, and htb-1 pCrIND:CrIND^K124R:GFP at stage 14.

(K–N) Fruit morphology of WT (K), IAA mock (L), or IAA (M) treatment on htb-1 and htb-1 pCrIND:iaaM (N) at stage 17.

(O) Shoulder index measurements of fruits from WT, htb-1 ± IAA treatment, and htb-1 pCrIND:iaaM plants.

(P–S) Fruit morphology of WT (P), crful-1 (Q), crful-1;crind-1^ge (R), and crful-1;htb-1 (S) at stage 17. Red dots indicate the location from where SEMs were taken in (T)–(W).

(T–W) SEM images of valve epidermal cells of WT (T), crful-1 (U), crful-1;crind-1^ge (V), and crful-1;htb-1 (W) at stage 17.

(X) Expression analysis of CrIND in stage-14 fruits of WT and htb-1. n.s. indicates no statistically significant difference from WT.

Scale bars in (A), (B), and (E)–(H), 150 μm; (K)–(N) and (P)–(S), 5 mm; and (T)–(W), 50 μM. Error bars in (C), (D), (I), (J), and (X) represent SD of three biological replicates and in (O) represent SD of 30 individual fruits. ^∗∗p < 0.01 (Student’s t test). See also Figure S3 and Data S1 and S2.