Effect of fluoride treatment on gene expression in tea plant (Camellia sinensis)

Abstract

Tea plant is a typical fluorine (F) accumulator. F concentration in mature tea leaves is several hundred times higher than that in normal field crops. Long-term consumption of teas with high level F will increase the risks of dental and skeletal fluorosis. The mechanism of F accumulation in tea stands unclear. RNA-Seq and digital gene expression (DGE) techniques were used to investigate the effect of F on the differential expressions of transcriptome in tea plant. The results showed that F content in mature tea leaves was increased with increase in F concentration of cultural solution and duration of F treatment time. Based on comparison with data of GO, COG, KEGG and Nr databases, 144 differentially expressed unigenes with definite annotation were identified. Real-time reverse transcription PCR (qRT-PCR) was used to validate the effect of F on expression of 5 unigenes screened from the 144 unigenes. F treatment induced the expression of defense genes such as receptor-like kinases (RLKs) and U-box domain-containing protein. Based on the present study, F uptake is considered to be related to calcium-transporting ATPase, especially autoinhibited Ca2+ ATPase (ACAs) which was activated by the RLKs and worked as a carrier in uptake of F by tea plant.

Transcriptome Analysis Reveals the Mechanism of Fluoride Treatment Affecting Biochemical Components in Camellia sinensis

“…Therefore, the content and proportion of bioactive components in tea leaves directly determine the quality and value of the tea [25]. Consistent with a report by Li et al (2017) [20], the results in the presents study showed that F content in leaves of C. sinensis increased significantly with F treatment over time.…”

“…Therefore, the content of F in C. sinensis leaves is even employed as one of the indicators to evaluate the quality of tea [19]. On the other hand, Li et al (2017) used RNA-Seq and digital gene expression (DGE) techniques to explore the accumulation mechanism of F in C. sinensis , and the results suggest that F uptake is associated with calcium transport ATPase, especially Ca 2+ ATPase (ACAs) activated by RLK, as a carrier for the absorption of F in C. sinensis [20]. However, the molecular mechanism by which F affects the main bioactive components of tea leaves remains unclear.…”

Analysis of Differentially Expressed Genes in Tissues of Camellia sinensis during Dedifferentiation and Root Redifferentiation

“…To validate the gene expression results of transcriptome, qRT-PCR was employed to determine the expression of 9 genes related to auxins and cytokinins regulation (Table 3) on Applied Biosystems™ StepOnePlus™ Real-Time PCR System (ABI, Carlsbad, CA, USA) by using SYBR Premix Ex TaqTM II (TaKaRa Biotechnology Co., Ltd., Dalian, China) according to the previous paper 50 . PCR primers were designed by primer-blast (https://www.ncbi.nlm.nih.gov/tools/primer-blast/) with default parameters except the product size (100–250 bp), and the primers were ordered from Sangon Biotech (Shanghai) Co., Ltd.…”

De novo transcriptome assembly of fluorine accumulator tea plant Camellia sinensis with fluoride treatments

“…‘JK2’ were cultured by hydroponic method in a climate chamber at 25±2 °C, 70±10% relative humidity and 12 h light/12 h dark 16 . The nutrient solution was renewed weekly with formula as below: 100.05 mg/L NH 4 NO 3 , 34.68 mg/L KH 2 PO 4 , 1.64 mg/L K 2 HPO 4 , 2.15 mg/L CaSO 4 ·2H 2 O, 49.00 mg/L MgSO 4 ·7H 2 O, 33.32 mg/L Al 2 (SO 4 ) 3 ·10H 2 O, 0.28 mg/L FeSO 4 ·7H 2 O, 14.21 mg/L Na 2 SiO 3 ·9H 2 O, 5.00 mg/L H 3 BO 3 , 3.00 mg/L MnSO 4 , 0.44 mg/L ZnSO 4 ·7H 2 O, 0.16 mg/L CuSO 4 ·5H 2 O, 0.16 mg/L Na 2 MoO 4 ·2H 2 O, and the pH of the solution was adjusted to 4.8–5.2 by 0.1 mol/L HCl or 0.1 mol/L NaOH 16 . After eight weeks acclimation in the nutrient solution, the tea plants were treated with three levels of F (0, 5, 20 mg/L).…”

“…To classify the functions of contigs, GO annotation was performed using Blast2GO software 20 , and KEGG orthology and pathway annotations were obtained by KAAS (KEGG Automatic Annotation Server). These methods are expanded versions of descriptions in our related work 16 .…”