Shading Effects on Leaf Color Conversion and Biosynthesis of the Major Secondary Metabolites in the Albino Tea Cultivar “Yujinxiang”

Abstract

Albino became a novel kind of tea cultivar in China recently. In this study, transcriptome and whole-genome bisulfite sequencing (WGBS) were employed to investigate the shading effects on leaf color conversion and biosynthesis of three major secondary metabolites in the albino tea cultivar “Yujinxiang”. The increased leaf chlorophyll level was likely the major cause for shaded leaf greening from young pale or yellow leaf. In comparison with the control, the total catechin level of the shading group was significantly decreased and the abundance of caffeine was markedly increased, while the theanine level was nearly not influenced. Meanwhile, differentially expressed genes (DEGs) enriched in some biological processes and pathways were identified by transcriptome analysis. Furthermore, whole-genome DNA methylation analysis revealed that the global genomic DNA methylation patterns of the shading period were remarkably altered in comparison with the control. In addition, differentially methylated regions (DMRs) and the DMR-related DEG analysis indicated that the DMR-related DEGs were the critical participants in biosynthesis of the major secondary metabolites. These findings suggest that DNA methylation is probably responsible for changes in the contents of the major secondary metabolites in Yujinxiang.

Comparative Analysis of the Morphological, Physiological, Proteomic, and Metabolic Mechanisms of the “Biloxi” Blueberry Response to Shade Stress

“…C4H acts as a rate-limiting enzyme in phenylpropanoid biosynthesis and exhibits the same markedly reduced expression levels in the shading treatment group, which may lead to differential accumulation of p -coumaroyl-CoA upstream of flavonoid biosynthesis. In this study, 14 DEPs involved in flavonoid biosynthesis, including CHS, F3H, F3′,5′H, and ANS, were significantly downregulated during the shading period ( Figure 7 ), which was similar to the results reported by Xu et al (2020) . Previous studies have suggested that an inactivating mutation of CHS can lead to decreased flavonoid accumulation in plants ( Li et al, 1993 ).…”

Screening the Key Region of Sunlight Regulating the Flavonoid Profiles of Young Shoots in Tea Plants (Camellia sinensis L.) Based on a Field Experiment

“…Liu et al reported that shade treatment barely impacted the TC content of the light-sensitive albino tea cultivar ‘Yujinxiang’, along with a greater reduction of quercetin and lower reduction of kaempferol [ 35 ]. A decrease in TC content was also observed in the young shoots of the albino tea cultivar ‘Yujinxiang’ under shade treatment [ 38 ]. Different tea cultivars and different growing stages of tea plants, such as plant age, cultivation method (pot culture or field culture), and leaf maturity, are non-negligible factors affecting the responses of tea plants to altered light conditions.…”

Quantitative Analysis of UV-B Radiation Interception and Bioactive Compound Contents in Kale by Leaf Position According to Growth Progress

“…A previous study indicated that flavonol profiles were highly associated with characteristics that were related to canopy structure and light interception ( Martínez-Lüscher et al, 2019 ). One of the main flavonoids, catechins, in an albino tea cultivar, significantly decreased with plant shading, which was associated with DNA methylation involved in the flavonoid biosynthesis pathway ( Xu et al, 2020 ). In this study, RSA levels in the upper leaves were also highest for both growth stages ( Figures 5E , F ).…”