Nitrogen-Regulated Theanine and Flavonoid Biosynthesis in Tea Plant Roots: Protein-Level Regulation Revealed by Multiomics Analyses

Abstract Background: Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance, but the regulation mechanism of exogenous ABA on tea plants under drought stress was rarely reported. Results: The results showed that the exogenous ABA significantly induced the metabolic pathways of tea leaves under drought stress, including the chlorophyll synthesis, photosynthesis, sucrose and starch metabolism, TCA cycle, glycolysis, lipid metabolism and flavonoids biosynthesis. In which, the exogenous ABA could up-regulated the genes related to lipid metabolism and flavonoid biosynthesis, including LPCAT , ALDH, FLS, CHI, DFR, and down-regulated the genes related to lipid metabolism and flavonoid biosynthesis, including FATB, EKI, DGK , PAL, 4CL . The exogenous ABA could also increase the contents of flavone, anthocyanins, flavonol, isoflavone of tea leaves under drought stress, including delphinidin 3-O-glucosidewere, cyanidin 3-O-rutinoside, kaempferitrin, sakuranetin, prunetin, kaempferol, and decrease the contents of glycerophospholipids, glycerolipids and fatty acids of tea leaves under drought stress, including LysoPE 14:0, LysoPE 16:0, LysoPE 18:0, LysoPE 18:1, LysoPC 15:1 and LysoPC 16:0. And there were strong correlations between the genes and metabolites. Conclusions: The results suggested that the exogenous ABA could alleviate the damages of tea leaves under drought stress through inducing the expressions of the genes and altering the contents of metabolites in response to drought stress. The data also provide a good foundation for further research on the roles of the genes and metabolites in response to ABA.

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Proton release from tea plant (Camellia sinensis L.) roots induced by Al(III) under hydroponic conditions

Soil Research ◽

10.1071/sr12099 ◽

2012 ◽

Vol 50 (6) ◽

pp. 482 ◽

Cited By ~ 4

Author(s):

Qing Wan ◽

Ren-kou Xu ◽

Xing-hui Li

Keyword(s):

Camellia Sinensis ◽

Soil Acidification ◽

Solution Culture ◽

Tea Plant ◽

Plant Roots ◽

Proton Release ◽

Constant Ph ◽

Initial Ph ◽

Tea Plants ◽

Hydroponic Conditions

The mechanisms for soil acidification induced by tea plant growth are not well understood. Proton release from tea plant (Camellia sinensis L.) roots induced by aluminium (Al(III)) in solution-culture experiments was examined with an automatic titration system, to determine the effect of Al(III) uptake by the plants on soil acidification. Results indicated that the uptake of Al(III) by tea plants led to proton release from their roots and thus an increase in soil acidification. The uptake of Al(III) by tea plants and the amount of protons released from the roots were greater at pH 4.5 than at pH 5.0 and 4.0 and increased with increasing initial Al(III) concentration in the culture solutions. With the same initial pH, the amount of protons released from tea plant roots at a constant pH was much higher than that at non-constant pH. The presence of ammonium increased the amount of protons released from tea plant roots. Therefore, the uptake of Al by tea plants and subsequent release of protons from their roots may be an important mechanism by which they acidify soils in tea gardens.

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Transcriptome analysis provides insights into the molecular bases in response to different nitrogen forms-induced oxidative stress in tea plant roots (Camellia sinensis)

Functional Plant Biology ◽

10.1071/fp20093 ◽

2020 ◽

Vol 47 (12) ◽

pp. 1073

Author(s):

Ziping Chen ◽

Huiping Li ◽

Tianyuan Yang ◽

Tingting Chen ◽

Chunxia Dong ◽

...

Keyword(s):

Oxidative Stress ◽

Transcriptome Analysis ◽

Molecular Mechanisms ◽

Redox Homeostasis ◽

Tea Plant ◽

Plant Roots ◽

Antioxidant Enzyme Activities ◽

Production Of Hydrogen ◽

N Deficiency ◽

Molecular Bases

Previous studies have suggested that the maintenance of redox homeostasis is essential for plant growth. Here we investigated how redox homeostasis and signalling is modulated in response to different nitrogen (N) forms in tea plant roots. Our results showed that both N deficiency and nitrate (NO3–) can trigger the production of hydrogen peroxide and lipid peroxidation in roots. In contrast, these responses were not altered by NH4+. Further, N deficiency and NO3–-triggered redox imbalance was re-established by increased of proanthocyanidins (PAs) and glutathione (GSH), as well as upregulation of representative antioxidant enzyme activities and genes. To further explore the molecular bases of these responses, comparative transcriptome analysis was performed, and redox homeostasis-associated differentially expressed genes (DEGs) were selected for bioinformatics analysis. Most of these genes were involved in the flavonoid biosynthesis, GSH metabolism and the antioxidant system, which was specifically altered by N deficiency or NO3–. Moreover, the interplay between H2O2 (generated by RBOH and Ndufab1) and hormones (including abscisic acid, auxin, cytokinin and ethylene) in response to different N forms was suggested. Collectively, the above findings contribute to an understanding of the underlying molecular mechanisms of redox homeostasis and signalling in alleviating oxidative stress in tea plant roots.

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