Tea is an important woody crop whose cultivation is severely limited by cold stress. Although 5-aminolevulinic acid (ALA) is known to be effective in alleviating abiotic stresses in plants, knowledge of the detailed metabolic response of tea plants to exogenous ALA-induced cold resistance is still limited—a lack which restricts our ability to protect tea plants from cold stress. In the present study, we performed an in-depth metabolomics analysis to elucidate the metabolic responses of tea plants to cold stress and explore the role of ALA in improving tea plants’ cold-resistance capability. Metabolic profiles showed that cold stress altered various metabolisms in tea plants, especially galactose composition and flavonoid contents. Furthermore, exogenous ALA application altered a series of metabolisms associated with cold stress. Importantly, increases in metabolites, including catechin, 3,4-dihydroxyphenylacetic acid and procyanidin B2, involved in the mechanisms of ALA improved tea plants’ cold resistance. Overall, our study deciphered detailed metabolic responses of tea plants to cold stress and elucidated the mechanisms of ALA in enhancing cold resistance through rebuilding compositions of soluble carbohydrates and flavonoids. Therefore, we have provided a basis for exogenous usage of ALA to protect tea plants from cold stress.

To systematically and comprehensively investigate the metabolic characteristics of coloring substances and floral aroma substances in Camellia oleifera petals with different colors, ultrahigh-performance liquid chromatography–mass spectrometry (UPLC–MS/MS) and headspace solid phase microextraction and gas chromatography–mass spectrometry (HS–SPME–GC–MS) metabolomics methods were applied to determine the metabolic profiles of white, candy-pink and dark-red petals. The results revealed that 270 volatile organic compounds were detected, mainly terpenoids, heterocyclic, esters, hydrocarbons, aldehydes, and alcohols, in which phenylethyl alcohol, lilac alcohol, and butanoic acid, 1-methylhexyl ester, hotrienol, alpha-terpineol and 7-Octen-4-ol, 2-methyl-6-methylene-, (S)-, butanoic acid, 2-methyl-, 2-methylbutyl ester, 2,4-Octadienal, (E,E)- could act as the floral scent compounds. A total of 372 flavonoid compounds were identified, and luteolin, kaempferol, cyanidin and peonidin derivatives were considered as the main coloring substances for candy-pink and dark-red petal coloration. In conclusion, this study intuitively and quantitatively exhibited the variations in flower color and floral scent of C. oleifera petal with different colors caused by changes in variations of flavonoids and volatile organic compound composition, and provided useful data for improving the sensory quality and breeding of C. oleifera petals.

Rapeseed’s (Brassica napus L.) colorful petals have important ornamental values. However, the mechanisms of regulating petals coloration in rapeseed are still unknown. In our study, we investigated the key differential coloring substances in nine rapeseed cultivars with different petal colors, and 543 metabolites were detected and characterized through UPLC-HESI-MS/MS. Among them, the kinds and contents of flavonols, flavones, and anthocyanidins were the main contributors to petals’ coloration. Tamarixetin-, quercetin-, butin-, naringenin- and luteolin-derivates were the main pigment bases in white and yellow petals. Peonidin-3,5-O-diglucoside, peonidin-3-O-(6″-O-caffeoyl)glucoside, and quercetin-derivatives were the main coloring substances in pink petals. Acylated cyanidin derivatives might lead to a series of different purple petal colors. Glycosylated anthocyanins were responsible for the coloration of rapeseed red petals, and peonidin-3-O-glucoside and kaempferol-derivatives were mainly detected from the red petals. These results provide comprehensive insights into the difference in flavonoid metabolites in rapeseed petals with different colors and supply theoretical supports for the breeding of novel colorful rapeseed cultivars.

The lipids accumulation characteristics in 23Camellia oleifera lines from northern margin distribution area were investigated through quantitative lipidomics. Combined lipids content-function analysis indicated that NQ1, HT1, HT2, ZA2, ZB1, ZB2, and SN2 lines had potential to develop functional foods due to abundant glycerolipids (GLs), glycerophospholipids (GPs), fatty acids (FAs), and prenol lipids (PRs). 673 lipids components were detected, and 293 differential components were identified in NQ1, ZA2, HB1, and HT1. 4 kinds free fatty acids (FFAs) were higher in NQ1, 5 triglycerides (TGs) were higher in HT1, and 2 phosphatidyl serines (PSs) and 1 phosphatidyl glycerol (PG) were higher in ZA2. GLs, GPs, and FFAs had strong relation at intra- and inter-category level. Glycerolipid metabolism, glycerophospholipid metabolism, and fatty acid biosynthesis were the significantly differential lipids pathways. Our study elucidated lipids differences of 23 C. oleifera lines, and offered valuable references for lipids biosynthesis, directional breeding, and lipids utilization.

Background: Environmental factors difference is the key factor for the difference in the production, transformation and accumulation of effective components in plants. UPLC-MS/MS and multivariate statistical methods were applied to describe the region difference of amides compounds in Chinese prickly ash peels from different regions and their correlation with climatic factors and soil factors. Results: Amides compounds contents were significantly higher in high altitude areas, with obvious altitude change trend. Two ecotypes were classified based on the amides compounds contents, one was the high altitude-cool type from Qinghai, Gansu, Sichuan and western Shaanxi province, and the other one was low altitude-warm type from eastern Shaanxi, Shanxi, Henan, Hebei and Shandong province. Amides compounds content were negatively correlated with annual mean temperature, max temperature of warmest month, mean temperature of wettest quarter and mean temperature of warmest quarter (P < 0.01). Except for hydroxy-γ-sanshool and ZP-amide A, the residual amides contents were significantly positively correlated with organic carbon, available nitrogen, phosphorus and potassium in soil and negatively correlated with soil bulk density. Low temperature, low precipitation and high organic carbon in soil were conducive to amides accumulation. Conclusions: This study aided in site specific exploration of high amides contents yielding samples, enriched the environment factors effects on amides compounds, and provided scientific foundation for the improvement of Chinese prickly ash peels quality and the location of high-quality production areas.

Light quality and sucrose-induced osmotic stress are known to cause anthocyanin synthesis in detached Lycium ruthenicum leaves. To identify the mechanisms by which the kind of light quality and sucrose concentration are induced, here, we conducted transcriptome sequencing in detached L. ruthenicum leaves treated with different qualities of light and sucrose concentrations. Leaves treated with blue light or sucrose showed a significantly increased total anthocyanins content compared to those treated with white light. Delphinidin-3-O-rutinoside and delphinidin-3-O-glucoside production were differentially regulated by the BL(−S), BL(+S), and WL(+S) treatments. The structural genes CHS, CHI, F3′H, F3′5′H, ANS, and UFGT were significantly up-regulated in leaves treated with blue light or sucrose. Leaves treated with blue light additionally showed up-regulation of the light photoreceptors CRY1, PIF3, COP1, and HY5. The anthocyanin-related genes NCED1, PYR/PYL, PP2C, SnRK2, and ABI5 were significantly up-regulated in leaves treated with sucrose, promoting adaptability to sucrose osmotic stress. Co-expression and cis-regulatory analyses suggested that HY5 and ABI5 could regulate LrMYB44 and LrMYB48 through binding to the G-box element and ABRE element, respectively, inducing anthocyanin synthesis in response to blue light or sucrose treatment. Candidate genes responsive to blue light or sucrose osmotic stress in the anthocyanin biosynthesis pathway were validated through quantitative reverse transcription PCR. These findings deepen our understanding of the mechanisms by which blue light and sucrose-induced osmotic stress regulate anthocyanin synthesis, providing valuable target genes for the future improvement in anthocyanin production in L. ruthenicum.