FIGURE 6.

The fruit phenotype of GNTI-RNAi is alleviated by ethephon and mimicked by indole-3-acetic acid (IAA). (A) Fruits of Micro-Tom GNTI-RNAi line #20 were photographed before (-) and after (+) treatment with 2% ethephon (2-chloro-ethyl-phosphonic acid), whose decomposition results in ethylene release. Ethephon was applied when irregular fruit coloration appeared (the border between yellow and orange areas was marked with a water-resistant pen). After 2 days, orange areas had turned red, while yellow-green areas remained patchy yellow-green. (B) After ethephon treatment of green fruits, GNTI-RNAi fruits developed a more homogeneous red color, but necrotic stalk regions remained after 11 days, compared to an untreated fruit from the same plant. (C–F) Detached Micro-Tom fruits (breaker stage) were infiltrated in parallel with either tap water (+ H₂O) or the auxin indole-3-acetic acid (+ IAA, 100 μM). Dpi, days post infiltration. After 4 days, IAA infiltration resulted in patchy coloration of both wild-type (wt) and MANII-RNAi fruits (#20), similar to GNTI-RNAi (#14) fruits. After 11 days, IAA-infiltrated fruits looked rotten. When opening the water-infiltrated fruits, signs of internal rotting were visible for GNTI-RNAi, and to some extent also for MANII-RNAi, but not for wt fruits.