A magic red coat on the surface of young leaves: anthocyanins distributed in trichome layer protectCastanopsis fissaleaves from photoinhibition

Abstract

The presence of anthocyanins in young leaves plays an important role in mitigation against photodamage and allows leaves to grow and develop normally. Many studies have reported that foliar anthocyanins are distributed within the vacuoles of mesophyll cells, so we explored the novel defence style of anthocyanin-coated young leaves of Castanopsis fissa, a dominant subtropical forest tree species, via removable trichomes. Anthocyanins were distributed in C. fissa leaf trichomes, which produced a red coating for the young leaves. As young leaves developed and then matured, the thickness and density of the anthocyanin trichomes progressively decreased, the coating finally disappearing, allowing greater utilization of light by mature leaves. In addition to anthocyanins, the trichomes contained a remarkably high amount of phenolics, which enable the red coating to be more efficient in screening ultraviolet light. Compared with mature leaves, the young leaves exhibited lower photosynthetic ability, which was attributable to the reduced chlorophyll and Rubisco contents. Removal of the red coating had little effect on the photosynthetic capacity of young leaves. However, the young leaves without the coating suffered greater light-induced photoinhibition due to greater excess light entering the chloroplast and the production of HO Our results suggest that the anthocyanin coating is photoprotective and this anthocyanin defence style may be a metabolically cost-effective way of adjusting the anthocyanin content in response to demand.

Metabolite Profiling of Sorghum Seeds of Different Colors from Different Sweet Sorghum Cultivars Using a Widely Targeted Metabolomics Approach

“…KEGG results showed that there were more differential metabolites in metabolic pathways and biosynthesis of secondary metabolites ( Figure 5). Secondary metabolites are mainly related to changes in the color of flowers and seeds and have a great effect on resistance to external aggression [26][27][28], which is consistent with many previous reports [29,30]. Anthocyanins and flavonoids determine the color and taste of fruits.…”

“…Anthocyanins are water-soluble plant pigments, and they are the main causes of different colors (such as white, red, black, and blue) in vegetables, seeds, fruits, and flowers. Anthocyanins can also help plants prevent damage caused by harsh environments such as cold and drought and avoid damage caused by fungi, bacteria, and viruses, as well as attract pollinators and help in seed dispersal [26][27][28]. Cyanidin-3-O-rhamnoglucoside (cyanidin-3-O-rutinoside) was reported to be the main anthocyanin in the peel of "Black Mission" and black (downregulated) between Z27 and HC4, between Z6 and HC4, and between Z6 and Z27, respectively.…”

Endogenous ascorbic acid delays ethylene-induced leaf senescence in Arabidopsis thaliana

“…After centrifugation at 13,000 × g and 4°C for 10 min, 0.25 mL of total soluble protein content in the supernatant was determined by the Bradford (1976) method, and bovine serum albumin (BSA) was used to construct the calibration curve. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) protein determination was estimated by SDS-PAGE electrophoresis following the procedures described by Zhang et al (2016). The electrophoresis was performed with a 4% stacking gel at 75 V for 30 min and a 12.5% separating gel at 110 V for 70 min.…”

Identification of a GLDH-overexpressing Arabidopsis mutant and its responses to high-light stress

“…Anthocyanins, flavonoids, and phenolics were extracted from 0.025 g of rosette leaves in 2 mL of methanol:HCl (99:1, v/v) solution at 4°C in the dark for 24 h. Absorption spectra of the extracts were recorded from 400 to 700 nm. The measurement of anthocyanin content was carried out by following the procedures described by Zhang et al (2016), while contents of flavonoids and phenolics were determined according to Fukumoto and Mazza (2000) with minor modifications. The content of total phenolics and flavonoids were calculated by the absorbance of the extract at 280 and 325 nm divided by the fresh mass (FM).…”