Figure 3.

Transient transformation of strawberry fruits with FvMAPK3 modulates their ripening. A, Relative FvMAPK3 expression levels at different developmental stages in diploid strawberry fruits, as determined by RT-qPCR. SG, small green fruit; MG, middle green fruit; BG, big green fruit; W, white fruit; T, turning fruit; R, red fruit. The mean values ± sem from three biological replicates are shown. B, MAPK3, MAPK6, and other MAPK-TEY kinase activity at different developmental stages in octoploid (F. × ananassa Ducherne, cv Benihoppe) and diploid (F. vesca, cv Fragola di Bosco) strawberry fruits. Total proteins were extracted, and MAPK activity was analyzed by immunoblotting with anti-p44/42 antibody. Anti-actin antibody was used as loading control. C, Phenotypes associated with the transient OE (FvMAPK3-OE) and silencing of FvMAPK3 (FvMAPK3-RNAi) in Benihoppe strawberry fruits. DAI, days after injection. Bars, 1 cm. D, Relative FvMAPK3 expression levels in transiently transformed strawberry fruits, as determined by RT-qPCR. Values are means ± sem of three biological replicates. Statistical significance was determined by Student’s t test. *P < 0.05, **P < 0.01. E, Anthocyanin contents in FvMAPK3-OE and FvMAPK3-RNAi fruits. Error bars represent sem of three biological replicates. Statistical significance was determined by Student’s t test. *P < 0.05, **P < 0.01. F, Relative expression levels of ripening-related genes in FvMAPK3-OE and FvMAPK3-RNAi fruits, as determined by RT-qPCR. FvACTIN was used as internal reference. Values are means ± sem of three biological replicates. Statistical significance was determined by Student’s t test. *P < 0.05, **P < 0.01.