Tuan P.A.,NARO Institute of Fruit Tree Science |
Bai S.,NARO Institute of Fruit Tree Science |
Yaegaki H.,NARO Institute of Fruit Tree Science |
Tamura T.,Research Institute for Agriculture |
And 3 more authors.
BMC Plant Biology | Year: 2015
Background: Red coloration of fruit skin is one of the most important traits in peach (Prunus persica), and it is mainly due to the accumulation of anthocyanins. Three MYB10 genes, PpMYB10.1, PpMYB10.2, and PpMYB10.3, have been reported as important regulators of red coloration and anthocyanin biosynthesis in peach fruit. In this study, contribution of PpMYB10.1/2/3 to anthocyanin accumulation in the fruit skin was investigated in the Japanese peach cultivars, white-skinned 'Mochizuki' and red-skinned 'Akatsuki'. We then investigated the relationships between allelic type of PpMYB10.1 and skin color phenotype in 23 Japanese peach cultivars for future establishment of DNA-marker. Results: During the fruit development of 'Mochizuki' and 'Akatsuki', anthocyanin accumulation was observed only in the skin of red 'Akatsuki' fruit in the late ripening stages concomitant with high mRNA levels of the last step gene leading to anthocyanin accumulation, UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT). This was also correlated with the expression level of PpMYB10.1. Unlike PpMYB10.1, expression levels of PpMYB10.2/3 were low in the skin of both 'Mochizuki' and 'Akatsuki' throughout fruit development. Moreover, only PpMYB10.1 revealed expression levels associated with total anthocyanin accumulation in the leaves and flowers of 'Mochizuki' and 'Akatsuki'. Introduction of PpMYB10.1 into tobacco increased the expression of tobacco UFGT, resulting in higher anthocyanin accumulation and deeper red transgenic tobacco flowers; however, overexpression of PpMYB10.2/3 did not alter anthocyanin content and color of transgenic tobacco flowers when compared with wild-type flowers. Dual-luciferase assay showed that the co-infiltration of PpMYB10.1 with PpbHLH3 significantly increased the activity of PpUFGT promoter. We also found close relationships of two PpMYB10.1 allelic types, MYB10.1-1/MYB10.1-2, with the intensity of red skin coloration. Conclusion: We showed that PpMYB10.1 is a major regulator of anthocyanin accumulation in red-skinned peach and that it activates PpUFGT transcription. PpMYB10.2/3 may be involved in functions other than anthocyanin accumulation in peach. The peach cultivars having two MYB10.1-2 types resulted in the white skin color. By contrast, those with two MYB10.1-1 or MYB10.1-1/MYB10.1-2 types showed respective red or pale red skin color. These findings contribute to clarifying the molecular mechanisms of anthocyanin accumulation and generating gene-based markers linked to skin color phenotypes. © 2015 Tuan et al.
Nakao S.,Kyoto Prefectural University |
Chikamori C.,Kyoto Prefectural University |
Chikamori C.,Aki Agricultural Promotion Center |
Hori A.,Kyoto Prefectural University |
Toda S.,NARO Institute of Fruit Tree Science
Japanese Journal of Applied Entomology and Zoology | Year: 2014
To detect biological differences between pyrethroid-resistant strains and pyrethroid-susceptible strains of the onion thrips, Thrips tabaci, developmental and ovipositional characteristics on the leaves of 5 varieties of persimmon and green bean were investigated by rearing trials using isofemale lines. In addition, suitability of 2 varieties of persimmon fruits as foods for thrips larvae was compared between a pyrethroid-resistant strain and a pyrethroid-susceptible strain of onion thrips. Irrespective of susceptibility levels to pyrethroid, while T. tabaci adults deposited eggs into persimmon leaves, few individuals completed larval development on the leaves, suggesting that T. tabaci does not develop on persimmon leaf throughout reproductive seasons. Both strains of T. tabaci successfully molted into adults when they fed on persimmon fruits, but survival rates in immature stages differed among varieties and developmental stages of the fruits. These differences may cause inter-specific and seasonal variation in injury levels by thrips attacking persimmon orchards. The pyrethroid-resistant strains showed lower fecundities compared to the pyrethroid-susceptible strains of onion thrips on green bean leaf. In conclusion, there was no evidence that unique characteristics other than susceptibility levels to pyrethroid insecticide contribute to pestilent levels of the onion thrips in commercial persimmon orchards.