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In higher plants, COP1 (Constitutively Photomorphogenic 1) acts as a central regulator of light-signaling networks and globally conditions the target proteins via the ubiquitin-proteasome pathway. However, the function of COP1-interacting proteins in light-regulated fruit coloration and development remains unknown in Solanaceous plants. Here, a COP1-interacting protein-encoding gene, SmCIP7 , expressed specifically in the eggplant (Solanum melongena L.) fruit, was isolated. Gene-specific silencing of SmCIP7 using RNA interference (RNAi) significantly altered fruit coloration, fruit size, flesh browning, and seed yield. SmCIP7 -RNAi fruits showed evident repression of the accumulation of anthocyanins and chlorophyll, indicating functional similarities between SmCIP7 and AtCIP7. However, the reduced fruit size and seed yield indicated SmCIP7 had evolved a distinctly new function. With the comprehensive application of HPLC-MS, RNA-seq, qRT-PCR, Y2H, BiFC, LCI, and dual-luciferase reporter system (DLR™), it was found that SmCIP7, a COP1 interactive protein in light signaling promoted anthocyanin accumulation, probably by regulating the transcription of SmTT8. Additionally, the drastic up-regulation of SmYABBY1 , a homologous gene of SlFAS , might account for the strongly retarded fruit growth in SmCIP7 -RNAi eggplant. Altogether, this study proved that SmCIP7 is an essential regulatory gene to modulate fruit coloration and development, serving as a key gene locus in eggplant molecular breeding. • Silencing of SmCIP7 notably altered the coloration, size, flesh browning, and seed yield of eggplant fruit. • SmCIP7 promotes anthocyanin accumulation by regulating the transcription of SmTT8. • SmCIP7 promotes eggplant fruit growth by regulating the transcription of SmYABBY1. • The repressed metabolic flux towards anthocyanin enhanced chlorogenic acid accumulation. [ABSTRACT FROM AUTHOR]

• Partial replacement of red and blue with green light increased the survival of DRC grafted tomato seedlings. • Green light boosted graft union formation of DRC grafted seedlings. • Green light facilitated root regeneration of DRC grafted seedlings. • Green light increased the activity of antioxidant enzymes and photosynthesis. Double-root-cutting (DRC) grafting is a new grafting method that makes it possible to ship grafted seedlings without using plug trays, through cutting off the roots of both scion and rootstock. However, graft healing and root regeneration are the two important factors determining the survival of the DRC grafted plants. Recent studies have shown that green light plays a crucial role in plant growth and development. We hypothesized that green light could stimulate the graft healing and root regeneration of the rootstock in DRC grafted seedlings. To test this hypothesis, we used tomato seedlings (Solanum lycopersicum cv. Beaded Curtain grafted on cv. Rootstock No. 1) exposed to white LED lamp (W) as a control (CK). In the treatment group, green light (10, 20 and 30%) was added to the red and blue spectrum without changing the intensity of red and blue fractions. The effects of different light qualities on graft union formation, survival rate, rooting of the rootstock hypocotyls, activities of antioxidant enzymes, chlorophyll content and grafted seedling quality of grafted tomato seedlings were then studied. Compared with DRC grafted seedlings exposed to the same light intensity, addition of 30% green light to red and blue lights increased the activities of antioxidant enzymes, chlorophyll content, plant height and index of seedling strength of grafted seedlings, showed a more positive effect on the development and performance of grafted seedlings, and promoted graft union, rootstock rooting and grafted seedling growth. Increasing the proportion of green light brought about better graft union and rootstock rooting. Our results showed that green light may reduce the degree of stomatal opening and transpiration rate during the early stages of grafting. Green light increased the activity of antioxidant enzymes, which was enhanced tissue lignification. Photosynthesis was driven by green light, which improved the development of aboveground parts, enhanced the transport of auxin from leaves to rooting zone, and promoted hypocotyl rooting of DRC grafted tomato seedlings. [Display omitted] [ABSTRACT FROM AUTHOR]