Down-regulation of NCED leads to the accumulation of carotenoids in the flesh of F1 generation of peach hybrid

Abstract

Flesh color is an important target trait in peach [Prunus persica (L.) Batsch] breeding. In this study, two white-fleshed peach cultivars were crossed [Changsong Whitepeach (WP-1) × ‘Xiacui’], and their hybrid F1 generation showed color segregation of white flesh (BF1) and yellow flesh (HF1). Metabolome analysis revealed that the flesh color segregation in the hybrid F1 generation was related to the carotenoid content. The decrease in β-carotene and β-cryptoxanthin in BF1 flesh and increase in β-cryptoxanthin oleate, rubixanthin caprate, rubixanthin laurate and zeaxanthin dipalmitate in HF1 flesh contributed to their difference in carotenoid accumulation. Transcriptome analysis demonstrated that compared with BF1, HF1 showed significant up-regulation and down-regulation of ZEP and CCD8 at the core-hardening stage, respectively, while significant down-regulation of NCED in the whole fruit development stage. The down-regulation of NCED might inhibit the breakdown of the violaxanthin and its upstream substances and further promote the accumulation of carotenoids, resulting in yellow flesh. Therefore, NCED may be a key gene controlling the fruit color traits of peach. In this study, targeted metabolomics and transcriptomics were used to jointly explore the mechanism controlling the fruit color of peach, which may help to identify the key genes for the differences in carotenoid accumulation and provide a reference for the breeding of yellow-fleshed peach.

Multi-omics analysis provides new insights into the changes of important nutrients and fructose metabolism in loquat bud sport mutant

“…The flesh were ground to a fine powder for experiments in liquid nitrogen. The content of carotenoids in the flesh was determined by the acetone-extraction method according to Song et al. (2022a) .…”

“…Pathway maps illustrating the key metabolites and genes related to fructose metabolism were generated using TBtools ( Chen et al., 2020 ) and Adobe Illustrator 2021. Total RNA extraction and quantitative real-time polymerase chain reaction (qRT-PCR) analysis were conducted according to the protocol outlined by Song et al. (2022a) .…”

Metabolomics to understand metabolic regulation underpinning fruit ripening, development, and quality

“…Different peach varieties produce red mesocarp if accumulating anthocyanins and yellow mesocarp if accumulating carotenoids, while white peaches do not accumulate high levels of either pigment ( Cantín et al , 2009 ). Consumers prefer yellow peaches in Western countries but white varieties in Eastern countries ( Song et al , 2022 ). As discovered by analysing 35 genotypes, ancestral species of peach display white flesh, and during domestication, a mutation in a carotenoid cleavage dioxygenase resulted in yellow-flesh peaches with different flesh color.…”

“…As discovered by analysing 35 genotypes, ancestral species of peach display white flesh, and during domestication, a mutation in a carotenoid cleavage dioxygenase resulted in yellow-flesh peaches with different flesh color. Furthermore, an F 1 population of a white × yellow cross revealed that down-regulation of the 9-cis-epoxycarotenoid dioxygenase gene also produced yellow traits ( Song et al , 2022 ). White and yellow peaches do not differ only in flesh color, but also display a different aroma repertoire.…”

Genome-Wide Identification and In-silico Expression Analysis of CCO Gene Family in Sunflower (Helianthus annnus)

“…Furthermore, NCED genes have been observed to evolve relatively slowly (Song et al, 2022). This slow rate of evolution might play a role in the functional divergence of NCED subfamilies across different tissues.…”