Transcriptomic analysis of the effect of shaking and tumbling degree on quality formation of Wuyi rock tea.

Shaking and tumbling are extremely important for the formation of the special flavor of Wuyi rock tea. In this study, we analyzed the effects of different shaking and tumbling degrees on the quality index content of tea leaves and determined changes in gene expression in tea leaves using RNA sequencing technology. On this basis, the correlation between gene expression intensities in tea leaves and tea quality index content was analyzed. The results showed that heavy shaking and tumbling (MW3) increased gene expression of metabolic pathways, biosynthesis of secondary metabolites, starch and sucrose metabolism, biosynthesis of amino acids, glycine, serine, and threonine metabolism, alpha-linolenic acid metabolism pathways and decreased gene expression of flavonoid biosynthesis, carbon fixation in photosynthetic organisms, phenylpropanoid biosynthesis, and plant hormone signal transduction pathways in tea leaves, which in turn increased the content of caffeine, soluble sugar, amino acid and decreased the content of flavone, tea polyphenol, catechin component in tea leaves; the opposite was true for light shaking and tumbling. Second, this study found that MW3 was more beneficial in improving the mellowness, sweetness, and fresh and brisk taste of tea leaves and reducing the bitterness of tea leaves. This study provides some references to guide the processing of Wuyi rock tea with different flavors. PRACTICAL APPLICATION: Heavy shaking and tumbling was more beneficial in improving the mellowness, sweetness, and fresh and brisk taste of tea leaves and reducing the bitterness of tea leaves. Therefore, the degree of shaking and tumbling in Wuyi production can be appropriately improved to produce high-quality tea and improve the economic benefits of tea.

Distribution of and Temporal Variation in Volatiles in Tea (Camellia sinensis) Flowers during the Opening Stages.

Tea (Camellia sinensis) flowers emit a large amount of volatiles that attract pollinators. However, few studies have characterized temporal and spatial variation in tea floral volatiles. To investigate the distribution of volatiles within tea flowers and their variation among opening stages, volatile components from different parts of tea flowers and different opening stages were collected by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry. A total of 51 volatile compounds of eight chemical classes were identified in the tea flowers. Volatile compounds were most abundant in tea flowers of the Shuchazao cultivar. Acetophenone, 1-phenylethanol, 2-phenylethanol, and benzyl alcohol were the most abundant volatiles. Terpenes were common in the sepals, and benzoids were common in the stamens. The fatty acid derivatives were mainly distributed in the pistils and receptacles and were less abundant in the petals, sepals, and stamens. During the opening phase of tea flowers, the volatile content increased 12-fold, which mainly stemmed from the increase in benzoids. These results enhance our understanding of the formation of volatiles in tea flowers.

[Plant regeneration of Withania somnifera].

OBJECTIVE: To study tissue culture and plant regeneration of Withania somnifera. METHOD: Leaves of W. somnifera were used for explants, effects of different plant growth substances on callus and shoot induction were studied, different medium and plant growth substances for rooting induction was optimized. RESULT AND CONCLUSION: The best plant growth substances combination for callus induction was MS + 1.0 mg x L(-1) 2,4-D + 0.1 mg x L(-1) KT. The optimal medium for germination was MS + 1.0 mg x L(-1) 6-BA + 0.1 mg x L(-1) NAA. The best medium and plant growth substances combination for rooting induction was 1/2MS + 0.5 mg x L(-1) NAA, transplant survival rate of plantlet reached 92% in humus soil-pearlite (1:1).

[Scopolamine and hyoscyamine synthesis in hair roots culture of Datura metel].

OBJECTIVE: To establish the hair roots culture system of Datura metel and study the hair roots growth and biosynthesis of scopolamine and hyoscyamine in hair roots culturing system. METHOD: Direct degermed cotyledon of wild D. metel was infected by Agrobacterium tumefaciens strain C58C1 to obtain hair roots. Growth curves and scopolamine and hyoscyamine biosynthesis curves were determined. The scopolamine and hyoscyamine from different hair roots lines were examined by HPLC. RESULT: Hair roots induction rate reached 70%. After 25 days cultured in 1/2 MS liquid nutrient medium, the hair roots weight, content of scopolamine and hyoscyamine reached maximum, tow high efficient accumulation hyoscyamine and scopolamine hair roots lines M1 and M2 were obtained. The medial accumulation coefficient of hyoscyamine and scopolamine were 2.53 times and 5.37 times compared with the leaves of wild D. metel respectively. CONCLUSION: The established hair roots induction and culture system of D. metel provided a foundation for further obtaining scopolamine and hyoscyamine.

[Culture in vitro and plant regeneration of Panax japonicus].

OBJECTIVE: To study the condition of culture in vitro and plant regeneration of Panax japonicus. METHODS: Embryos, stems and leaves of P. japonicus were used as explants, effects of different hormones for callus induction and plant regeneration were studied and optimized. RESULTS: The optimal way to obtain sterile explant for seeds was sterilized in 75% ethyl alcohol for 60 s then 0.1% HgCL2 for 12 min; Stems and leaves were sterilized in 75% ethyl alcohol for 15 s then 5% NaClO for 5 min. Used MS as basic medium, the optimal hormones combination for callus induction of embryos, stems and leaves were MS + 1.5 mg/L NAA + 1.5 mg/L 2, 4-D + 0.1 mg/L KT; MS + 1.5 mg/L NAA + 1.0 mg/L 2,4-D + 0.1 mg/L KT; MS + 1.5 mg/L NAA + 1.0 mg/L 2,4-D + 0.2 mg/L KT respectindy under the illumination. But under the darkness,the optimal callus induction hormones combination for embryos leaves were MS + 1.0 mg/L NAA + 1.5 mg/L 2,4-D +0.2 mg/L KT; 1.5 mg/L NAA + 1.5 mg/L 2,4-D + 0.1 mg/L KT; MS + 1.5 mg/L NAA + 1.0 mg/L 2,4-D + 0.1 mg/L KT respectivety. The optimal medium for germination was MS + 3.0 mg/L 6-BA + 1.0 mg/L GA3. The optimal medium for roots generation was MS + 1.0 mg/L 6-BA + 3.0 mg/L IBA. CONCLUSION: We establish the system of culture in vitro and plant regeneration for P. japonicus.

[Culture of hairy roots of Panax japonicus and ginsenoside re synthesis].

OBJECTIVE: To establish the induction method and culture system of hairy roots of Panax japonicus, and determine ginsenoside Re contents. METHOD: Hairy roots of P. japonicus was obtained through infecting pre-incubated terrestrial stem with the Agrobacterium tumefaciens strain C58C1; its enlarging culture was carried out on the 1/2MS medium, and growing characteristics were measured. The transformation of T-DNA was examined by PCR and ginsenoside Re content was determined by HPLC. RESULT: A. tumefaciens strain C58C1 could make terrestrial stem of P. japonicus bring about hairy roots, the max inductivity was 90% when infecting for 25 min. The PCR examination result showed that rolB genes could be inserted into the hair roots of P. japonicus. All hairy roots dould synthesize ginsenoside Re, among them, the max content was PJ8 with 60. 26 mg x g(-1). CONCLUSION: It was reported for the first time that the induction method and culture system of hairy roots of P. japonicus were established successfully, which provided a foundation for producing high content ginsenoside Re through culturing the hairy roots of P. japonicus.