Open AccessManipulation of ZDS in tomato exposes carotenoid‐ and ABA‐specific effects on fruit development and ripening
Author(s) -
McQuinn Ryan P.,
Gapper Nigel E.,
Gray Amanda G.,
Zhong Silin,
Tohge Takayuki,
Fei Zhangjun,
Fernie Alisdair R.,
Giovani James J.
Publication year - 2020
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.13377
Subject(s) - carotenoid , biology , ripening , lycopene , abscisic acid , mutant , genetically modified tomato , solanum , biochemistry , carotene , arabidopsis , gene , arabidopsis thaliana , botany , transgene , genetically modified crops
Summary Spontaneous mutations in fruit‐specific carotenoid biosynthetic genes of tomato ( Solanum lycopersicum ) have led to improved understanding of ripening‐associated carotenogenesis. Here, we confirm that ZDS is encoded by a single gene in tomato transcriptionally regulated by ripening transcription factors RIN, NOR and ethylene. Manipulation of ZDS was achieved through transgenic repression and heterologous over‐expression in tomato. CaMV 35S‐driven RNAi repression inhibited carotenoid biosynthesis in all aerial tissues examined resulting in elevated levels of ζ ‐carotene isomers and upstream carotenoids, while downstream all trans‐ lycopene and subsequent photoprotective carotenes and xanthophylls were diminished. Consequently, immature fruit displayed photo‐bleaching consistent with reduced levels of the photoprotective carotenes and developmental phenotypes related to a reduction in the carotenoid‐derived phytohormone abscisic acid (ABA). ZDS ‐repressed ripe fruit was devoid of the characteristic red carotenoid, all trans‐ lycopene and displayed brilliant yellow pigmentation due to elevated 9,9′ di‐cis‐ζ ‐carotene. Over‐expression of the Arabidopsis thaliana ZDS ( AtZDS ) gene bypassed endogenous co‐suppression and revealed ZDS as an additional bottleneck in ripening‐associated carotenogenesis of tomato. Quantitation of carotenoids in addition to multiple ripening parameters in ZDS‐altered lines and ABA‐deficient fruit‐specific carotenoid mutants was used to separate phenotypic consequences of ABA from other effects of ZDS manipulation and reveal a unique and dynamic ζ ‐carotene isomer profile in ripe fruit.