Anthocyanin Content In Plants Research Articles

Foliar Application of Cerium Oxide-Salicylic Acid Nanoparticles (CeO2:SA Nanoparticles) Influences the Growth and Physiological Responses of Portulaca oleracea L. under Salinity.

In the present study, the effects of foliar application of salicylic acid (100 μM), cerium oxide (50 mg L−1), and cerium oxide:salicylic acid nanoparticles (CeO2: SA-nanoparticles, 50 mg L−1 + 100 μM) on the growth and physiological responses of purslane (Portulaca oleracea L.) were examined in non-saline and saline conditions (50 and 100 mM NaCl salinity). Foliar applications mitigated salinity-induced adverse effects, and the highest plant height and N, P, Mg, and Mn content were recorded in the variant with non-saline × foliar use of CeO2: SA-nanoparticles. The highest values of fresh and dry weight were noted in the treatment with no-salinity × foliar use of CeO2:SA-nanoparticles. The highest number of sub-branches was observed in the foliar treatments with CeO2-nanoparticles and CeO2:SA-nanoparticles without salinity stress, while the lowest number was noted in the 100 mM NaCl treatment. Moreover, the foliar application of CeO2:SA-nanoparticles and cerium-oxide nanoparticles improved the total soluble solid content, K, Fe, Zn, Ca, chlorophyll a, and oil yield in the plants. The salinity of 0 and 50 mM increased the K content, 1000-seed weight, total soluble solid content, and chlorophyll b content. The use of 100 mM NaCl with no-foliar spray increased the malondialdehyde, Na, and H2O2 content and the Na+/K+ ratio. No-salinity and 50 mM NaCl × CeO2: SA-nanoparticle interactions improved the anthocyanin content in plants. The phenolic content was influenced by NaCl100 and the foliar use of CeO2:SA-nanoparticles. The study revealed that the foliar treatment with CeO2:SA-nanoparticles alleviated the side effects of salinity by improving the physiological responses and growth-related traits of purslane plants.

Effects of amendments of PCB-containing Hudson River sediment on soil quality and biochemical and growth response of cucumber (Cucumis sativus L. cv ‘Wisconsin SMR 58’)

Approximately 200 million m3 of sediments are dredged every year in the United States. Of this amount, 2.3–9 million m3 are contaminated to the extent that they require special, and often costly, handling. Therefore, there is a pressing need to develop appropriate technology for the safe utilization of these sediments, especially in the case of the Hudson River, which is well known to demonstrate significant polychlorinated biphenyls (PCBs) contamination. Hence, the aim of the present study was to examine the influence of different doses of Hudson River sediments (10%, 25%, 50%, 75% and 100% admixtures) on soil quality and on the biochemical and growth response of cucumber (Cucumis sativus L. cv ‘Wisconsin SMR 58’), used as potential phytoremediation tool for sediment-borne PCBs. A sediment/soil admixture was found to significantly decrease the nitrogen (N) content in the substratum; in addition, phosphorus (P) content was significantly increased by 50–100% sediment, while potassium (K) content was significantly increased by 10% sediment, and significantly decreased by >50% sediment. Although sediment treatment resulted in a gradual increase in PCB content in the soil-sediment substratum, exceeding the threshold effect concentration (TEC) for the ≥50% sediment admixture, the Microtox assay did not suggest toxicity to microorganisms. The results demonstrated also that admixture of 10–25% Hudson River sediment increased cucumber growth; however, higher doses led to growth inhibition, manifested as lower biomass and smaller leaves. Also, chlorophyll a and b content decreased with increasing doses of sediment. Phenylpropanoid and flavonol contents were significantly higher in plants grown in soil amended with 10% of sediment, but significantly lower in soil treated with a 100% sediment admixture. The anthocyanin content in plants was lower at admixtures of 50% and higher. The obtained results corresponded with the decreasing content of N and K.

Comparison of prediction power of three multivariate calibrations for estimation of leaf anthocyanin content with visible spectroscopy in Prunus cerasifera.

The anthocyanin content in leaves can reveal valuable information about a plant’s physiological status and its responses to stress. Therefore, it is of great value to accurately and efficiently determine anthocyanin content in leaves. The selection of calibration method is a major factor which can influence the accuracy of measurement with visible and near infrared (NIR) spectroscopy. Three multivariate calibrations including principal component regression (PCR), partial least squares regression (PLSR), and back-propagation neural network (BPNN) were adopted for the development of determination models of leaf anthocyanin content using reflectance spectra data (450–600 nm) in Prunus cerasifera and then the performance of these models was compared for three multivariate calibrations. Certain principal components (PCs) and latent variables (LVs) were used as input for the back-propagation neural network (BPNN) model. The results showed that the best PCR and PLSR models were obtained by standard normal variate (SNV), and BPNN models outperformed both the PCR and PLSR models. The coefficient of determination (R2), the root mean square error of prediction (RMSEp), and the residual prediction deviation (RPD) values for the validation set were 0.920, 0.274, and 3.439, respectively, for the BPNN-PCs model, and 0.922, 0.270, and 3.489, respectively, for the BPNN-LVs model. Visible spectroscopy combined with BPNN was successfully applied to determine leaf anthocyanin content in P. cerasifera and the performance of the BPNN-LVs model was the best. The use of the BPNN-LVs model and visible spectroscopy showed significant potential for the nondestructive determination of leaf anthocyanin content in plants.

Molecular cloning and characterization of anthocyanin biosynthesis genes in eggplant (Solanum melongena L.)

Eggplant is rich in anthocyanins, which are one of the important secondary metabolites and beneficial to human health. In this study, four anthocyanin biosynthesis genes, including chalcone synthase (SmCHS), chalcone isomerase (SmCHI), flavanone 3-hydroxylase (SmF3H) and dihydroflavonol 4-reductase (SmDFR), were isolated from eggplant. Their expression profiles were investigated along with other two structural genes (SmF3′5′H and SmANS) in different tissues, bagging, and low-temperature treatments. The highest expression levels were observed in peels except for SmF3H which was detected in stems, and SmF3H was also the exclusive gene that did not show correlation with anthocyanin content. Unlike purple peels of the control, the bagged fruits displayed white peels and had no anthocyanin accumulation, because of the expression of SmCHI, SmF3′5′H, SmDFR, and SmANS totally depended on light. As low temperature stimulates anthocyanin accumulation, all the six anthocyanin biosynthesis genes were up-regulated in cold stress experiment, and SmCHS increased most obviously. Moreover, early biosynthesis genes (SmCHS, SmCHI, and SmF3H) responded earlier than late biosynthesis genes (SmF3′5′H, SmDFR, and SmANS) under low temperature. Subcellular localization suggested that the enzymes encoded by the genes cloned in this study were all located in cytosol and nucleus. To further characterize the function, their ectopic expression in Arabidopsis was performed, and overexpression lines displayed higher anthocyanin accumulation in stems and siliques. The present study provides insight into anthocyanin biosynthesis in eggplant and may facilitate genetic engineering for improvement of the anthocyanin content in plants.

Light and the E3 ubiquitin ligase COP1/SPA control the protein stability of the MYB transcription factors PAP1 and PAP2 involved in anthocyanin accumulation in Arabidopsis

Anthocyanins are natural pigments that accumulate only in light-grown and not in dark-grown Arabidopsis plants. Repression of anthocyanin accumulation in darkness requires the CONSTITUTIVELY PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA-105 (COP1/SPA) ubiquitin ligase, as cop1 and spa mutants produce anthocyanins also in the dark. Here, we show that COP1 and SPA proteins interact with the myeloblastosis (MYB) transcription factors PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP)1 and PAP2, two members of a small protein family that is required for anthocyanin accumulation and for the expression of structural genes in the anthocyanin biosynthesis pathway. The increased anthocyanin levels in cop1 mutants requires the PAP1 gene family, indicating that COP1 functions upstream of the PAP1 gene family. PAP1 and PAP2 proteins are degraded in the dark and this degradation is dependent on the proteasome and on COP1. Hence, the light requirement for anthocyanin biosynthesis results, at least in part, from the light-mediated stabilization of PAP1 and PAP2. Consistent with this conclusion, moderate overexpression of PAP1 leads to an increase in anthocyanin levels only in the light and not in darkness. Here we show that SPA genes are also required for reducing PAP1 and PAP2 transcript levels in dark-grown seedlings. Taken together, these results indicate that the COP1/SPA complex affects PAP1 and PAP2 both transcriptionally and post-translationally. Thus, our findings have identified mechanisms via which the COP1/SPA complex controls anthocyanin levels in Arabidopsis that may be useful for applications in biotechnology directed towards increasing anthocyanin content in plants.

UV irradiance as a major influence on growth, development and secondary products of commercial importance in Lollo Rosso lettuce ‘Revolution’ grown under polyethylene films

The growth and production of anthocyanin, flavonoid and phenolic compounds were evaluated in Lollo Rosso lettuce ‘Revolution’ grown continuously under films varying in their ability to transmit UV radiation (completely transparent to UV, transparent above 320, 350, 370 and 380 nm and completely opaque to UV radiation). Plants were grown from seed under UV transparent and UV blocking films and destructively harvested 3–4 weeks after transplanting. Plants under a complete UV blocking film (UV400) produced up to 2.2 times more total above ground dry weight than plants under the UV transparent film. In contrast, anthocyanin content in plants under the UV blocking film was approximately eight times lower than in plants under a UV transparent film. Furthermore, there was a curvilinear relationship between the anthocyanin content and UV wavelength cutoff such that above 370 nm there was no further reduction in anthocyanin content. Fluorescence measurements indicated that photosynthetic performance index was 15% higher under the presence of UVB and UVA (UV280) than under the presence of UVA (UV320) and 53% higher than in the absence of UV radiation suggesting protection of the photosynthetic apparatus possibly by phenolic compounds. These findings are of particular importance as the potential of UV transmitting films to increase secondary compounds may offer the opportunity to produce plants commercially with increased health benefits compared to those grown under conventional films.

Anthocyanins: from plant to health

Anthocyanins are a group of natural occurring pigments responsible for the red-blue colour of many fruits and vegetables. Anthocyanins are of interest for two reasons because they cannot only be used in the technological field as natural colorants but also have important implications in the field of human health. Numerous studies indicate the potential effect that this family of flavonoids may have in reducing the incidence of cardiovascular disease, cancer, hyperlipidemias and other chronic diseases through the intake of anthocyanin-rich foods. This review examines existing literature in this area: from plant content and distribution to health implications, including the effect of agronomic and genetic modifications on the anthocyanin content of plants as well as other biotechnological factors and food processing. The bioavailability, metabolism, bioactivity, and epidemiology of anthocyanins will also be reviewed.