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The present study investigated the effect of salt stress on the development of adaptive responses and growth parameters of different coloured wheat genotypes. The different coloured wheat genotypes have revealed variation in the anthocyanin content, which may affect the development of adaptive responses under increasing salinity stress. In the early stage of treatment with salt at a lower NaCl concentration (100 mM), anthocyanins and proline accumulate, which shows rapid development of the stress reaction. A dose-dependent increase in flavonol content was observed for wheat genotypes with more intense purple-blue pigmentation after treatment with 150 mM and 200 mM NaCl. The content of Na⁺ and K⁺ obtained at different levels of salinity based on dry weight (DW) was more than 3 times greater than the control, with a significant increase of both ions under salt stress. Overall, our results demonstrated that coloured wheat genotypes with high anthocyanin content are able to maintain significantly higher dry matter production after salt stress treatment.

Hyperspectral analysis represents a powerful technique for diagnostics of morphological and chemical information from aboveground parts of the plants, but the real potential of the method in pre-screening of phenolics in leaves is still insufficiently explored. In this study, assessment of the sensitivity and reliability of non-invasive methods of various phenolic compounds, also analyzed by HPLC in chicory plants (Cichorium intybus L.) exposed to various color light pretreatments was done. The hyperspectral records in visible and near infrared (VNIR) spectra were recorded using a handheld spectrometer and relationships between the specific hyperspectral parameters and the contents of tested phenolic compounds in chicory leaves were analyzed. Moreover, the correlations between the hyperspectral parameters and related parameters derived from the multispectral fluorescence records were assessed to compare the sensitivity of both techniques. The results indicated a relatively high correlation of anthocyanin-related parameters (ARI, mARI, mACI indices) with the content of some of tested phenolic compounds (quercetin-3-gluconuride, isorhamnetine-3-gluconuride, etc.), as well as with fluorescence ANTH index. Similar trends were observed in flavonoid parameter based on the near infra-red spectral bands (700, 760 nm), which expressed a high correlation with chlorogenic acid. On the other hand, the most frequently used flavonoid (FLAVI) indices based on UV-to-blue band reflectance showed very weak correlations with phenolic compounds, as well as with fluorescence FLAV index. The detailed analysis of the correlation between reflectance and fluorescence flavonoid parameters has shown that the parameters based on spectral reflectance are sensitive to increase of UV-absorbing compounds from low to moderate values, but, unlike the fluorescence parameter, they are not useful to recognize a further increase from middle to high or very high contents. Thus, our results outlined the possibilities, but also the limits of the use of hyperspectral analysis for rapid screening phenolic content, providing a practical evidence towards more efficient production of bioactive compounds for pharmaceutical or nutraceutical use. • Spectral reflectance is sensitive to recognize of UV-absorbing compounds from low to moderate values. • High correlation of anthocyanin-related parameters (ARI, mARI, mACI indices) with the tested phenolics. • High correlation of flavonoid spectral reflectance indices with a chlorogenic acid content. • The reflectance-based FLAVI index showed very weak correlation with phenolic compounds. • The results outlined the possibilities, but also the limits of the use of hyperspectral analysis. [ABSTRACT FROM AUTHOR]

• Color shade pretreatment influenced the composition of phenolics in later growth stages of chicory. • Red light pretreatment led to an increase in quercetin derivatives in leaves. • Isorhamnetin and feruloyl malate were accumulated in plants exposed to orange light. • Blue light preferentially triggered production of isorhamnetin-3-glucoside. • Light environment in early growth stages induced long-term photoacclimation. Manipulation of spectral composition has been found to be an efficient way to influence the growth and quality of plant production in protected or controlled environments. The aim of this study was to compare the short- and long-term effects of early pretreatment with different color shades on the composition of phenolic compounds and photosynthetic pigments in Cichorium leaves. The analyses conducted immediately after color shade pretreatments at ˜40 μmol m−²s−1 (blue, red orange, white) indicated lower values of chlorophyll, anthocyanin and flavonoid indices, as well as of the majority of flavonoids, compared to those in the same plants subsequently grown for 4 weeks under higher white light with an intensity of ˜320 μmol m−²s−1. However, we observed significant differences in the contents of phenolics and pigments depending on previous color shade pretreatment in plants grown for 4 weeks in the same environment and in leaves grown during this period. The most significant effect was observed in plants pretreated with orange light, in which levels of isorhamnetin, its derivatives and feruloyl malate were increased, and kaempferol-3-(6"-acetyl)-glucoside levels were significantly decreased. Blue light pretreatment led to lower values of chlorogenic acid, caftaric acid and isorhamnetin-3-(6"-acetyl)-glucoside but a higher content of isorhamnetin-3-glucoside. Red light led to an increase in quercetin derivatives. Compared to plants grown under constant conditions, low light in the early growth phases led to the upregulation of feruloyl malate, caffeoyl malate and kaempferol derivatives. Nondestructive measurements enabled the identification of significant effects of light pretreatment on the chlorophyll contents, as well as the accumulation of flavonoids and anthocyanins in the epidermal leaf layer. The induction of specific metabolites influenced by the acclimation of plants to colored light environments may emphasize the environment‐induced biochemical responses associated with the remarkable plasticity of phenylpropanoid metabolism. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Central European Agriculture is the property of Journal of Central European Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)