Journal
JOURNAL OF EXPERIMENTAL BOTANY
Volume 63, Issue 1, Pages 341-354Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jxb/err284
Keywords
Carotenoid; chloroplast; chromoplast; colour; gene expression; fruit development; fruit ripening; loquat; plastid
Categories
Funding
- National Basic Research Program of China (973 Program) [2011CB100600]
- National Natural Science Foundation in China [30871691]
- Special Fund for Agro-scientific Research in the Public Interest of China [200903044]
Ask authors/readers for more resources
Loquat (Eriobotrya japonica Lindl.) can be sorted into red- and white-fleshed cultivars. The flesh of Luoyangqing (LYQ, red-fleshed) appears red-orange because of a high content of carotenoids while the flesh of Baisha (BS, white-fleshed) appears ivory white due to a lack of carotenoid accumulation. The carotenoid content in the peel and flesh of LYQ was approximately 68 mu g g(-1) and 13 mu g g(-1) fresh weight (FW), respectively, and for BS 19 mu g g(-1) and 0.27 mu g g(-1) FW. The mRNA levels of 15 carotenogenesis-related genes were analysed during fruit development and ripening. After the breaker stage (S4), the mRNA levels of phytoene synthase 1 (PSY1) and chromoplast-specific lycopene beta-cyclase (CYCB) were higher in the peel, and CYCB and beta-carotene hydroxylase (BCH) mRNAs were higher in the flesh of LYQ, compared with BS. Plastid morphogenesis during fruit ripening was also studied. The ultrastructure of plastids in the peel of BS changed less than in LYQ during fruit development. Two different chromoplast shapes were observed in the cells of LYQ peel and flesh at the fully ripe stage. Carotenoids were incorporated in the globules in chromoplasts of LYQ and BS peel but were in a crystalline form in the chromoplasts of LYQ flesh. However, no chromoplast structure was found in the cells of fully ripe BS fruit flesh. The mRNA level of plastid lipid-associated protein (PAP) in the peel and flesh of LYQ was over five times higher than in BS peel and flesh. In conclusion, the lower carotenoid content in BS fruit was associated with the lower mRNA levels of PSY1, CYCB, and BCH; however, the failure to develop normal chromoplasts in BS flesh is the most convincing explanation for the lack of carotenoid accumulation. The expression of PAP was well correlated with chromoplast numbers and carotenoid accumulation, suggesting its possible role in chromoplast biogenesis or interconversion of loquat fruit.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available