scholarly journals Influence of Chloroplast Defects on Formation of Jasmonic Acid and Characteristic Aroma Compounds in Tea (Camellia sinensis) Leaves Exposed to Postharvest Stresses

2019 ◽  
Vol 20 (5) ◽  
pp. 1044 ◽  
Author(s):  
Jianlong Li ◽  
Lanting Zeng ◽  
Yinyin Liao ◽  
Dachuan Gu ◽  
Jinchi Tang ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Camellia Sinensis ◽  
Defense Responses ◽  
Aroma Compounds ◽  
Green Leaf ◽  
Aroma Compound ◽  
Tea Leaves ◽  
Compound Formation ◽  
Wounding Stress ◽  
Oolong Tea

Characteristic aroma formation in tea (Camellia sinensis) leaves during the oolong tea manufacturing process might result from the defense responses of tea leaves against these various stresses, which involves upregulation of the upstream signal phytohormones related to leaf chloroplasts, such as jasmonic acid (JA). Whether chloroplast changes affect the formation of JA and characteristic aroma compounds in tea leaves exposed to stresses is unknown. In tea germplasms, albino-induced yellow tea leaves have defects in chloroplast ultrastructure and composition. Herein, we have compared the differential responses of phytohormone and characteristic aroma compound formation in normal green and albino-induced yellow tea leaves exposed to continuous wounding stress, which is the main stress in oolong tea manufacture. In contrast to single wounding stress (from picking, as a control), continuous wounding stress can upregulate the expression of CsMYC2, a key transcription factor of JA signaling, and activate the synthesis of JA and characteristic aroma compounds in both normal tea leaves (normal chloroplasts) and albino tea leaves (chloroplast defects). Chloroplast defects had no significant effect on the expression levels of CsMYC2 and JA synthesis-related genes in response to continuous wounding stress, but reduced the increase in JA content in response to continuous wounding stress. Furthermore, chloroplast defects reduced the increase in volatile fatty acid derivatives, including jasmine lactone and green leaf volatile contents, in response to continuous wounding stress. Overall, the formation of metabolites derived from fatty acids, such as JA, jasmine lactone, and green leaf volatiles in tea leaves, in response to continuous wounding stress, was affected by chloroplast defects. This information will improve understanding of the relationship of the stress responses of JA and aroma compound formation with chloroplast changes in tea.

scholarly journals Functional Characterization of An Allene Oxide Synthase Involved in Biosynthesis of Jasmonic Acid and Its Influence on Metabolite Profiles and Ethylene Formation in Tea (Camellia sinensis) Flowers

2018 ◽  
Vol 19 (8) ◽  
pp. 2440 ◽  
Author(s):  
Qiyuan Peng ◽  
Ying Zhou ◽  
Yinyin Liao ◽  
Lanting Zeng ◽  
Xinlan Xu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Jasmonic Acid ◽  
Camellia Sinensis ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Tea Leaves ◽  
Ethylene Formation ◽  
Horticultural Crops ◽  
Metabolite Profiles ◽  
Oxide Synthase

Jasmonic acid (JA) is reportedly involved in the interaction between insects and the vegetative parts of horticultural crops; less attention has, however, been paid to its involvement in the interaction between insects and the floral parts of horticultural crops. Previously, we investigated the allene oxide synthase 2 (AOS2) gene that was found to be the only JA synthesis gene upregulated in tea (Camellia sinensis) flowers exposed to insect (Thrips hawaiiensis (Morgan)) attacks. In our present study, transient expression analysis in Nicotiana benthamiana plants confirmed that CsAOS2 functioned in JA synthesis and was located in the chloroplast membrane. In contrast to tea leaves, the metabolite profiles of tea flowers were not significantly affected by 10 h JA (2.5 mM) treatment as determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry. Moreover, JA treatment did not significantly influence ethylene formation in tea flowers. These results suggest that JA in tea flowers may have different functions from JA in tea leaves and other flowers.

scholarly journals Differential Accumulation of Aroma Compounds in Normal Green and Albino-Induced Yellow Tea (Camellia sinensis) Leaves

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2677 ◽  
Author(s):  
Fang Dong ◽  
Lanting Zeng ◽  
Zhenming Yu ◽  
Jianlong Li ◽  
Jinchi Tang ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Raw Materials ◽  
Amino Acid Content ◽  
Aroma Compounds ◽  
Aroma Compound ◽  
Geranyl Diphosphate ◽  
Expression Levels ◽  
Green Leaves ◽  
Normal Green ◽  
High Amino Acid

Tea (Camellia sinensis) cultivars with green leaves are the most widely used for making tea. Recently, tea mutants with white or yellow young shoots have attracted increasing interest as raw materials for making “high-quality” tea products. Albino teas are generallycharacterized as having metabolites of relatively high amino acid content and lower catechin content. However, little is known about aroma compounds in albino tea leaves. Herein, we compared original normal leaves (green) and light-sensitive albino leaves (yellow) of cv. Yinghong No. 9. GC-MS was employed to analyze endogenous tea aroma compounds and related precursors. Quantitative real time PCR was used to measure expression levels of genes involved in biosyntheses of tea aromas.The total contents of most endogenous free tea aromas, including aroma fatty acid derivatives, aroma terpenes, and aroma phenylpropanoids/benzenoids, and their glycosidically bound aroma compounds, were lower in yellow leaves than in green leaves. The content of the key precursor geranyl diphosphate (GDP) and expression levels of key synthetic genes involved in the formation of linalool, a major aroma compound in cv. Yinghong No. 9, were investigated. Linalool content was lower in albino-induced yellow leaves, which was due to the lower GDP content compared with normal green leaves.

scholarly journals Duplication and transcriptional divergence of three Kunitz protease inhibitor genes that modulate insect and pathogen defenses in tea plant (Camellia sinensis)

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Junyan Zhu ◽  
Yaxian He ◽  
Xiaomei Yan ◽  
Lu Liu ◽  
Rui Guo ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Camellia Sinensis ◽  
Acid Methyl Ester ◽  
Defense Responses ◽  
Tea Plant ◽  
High Expression ◽  
Pathogen Infection ◽  
Evolutionary Patterns ◽  
Protein Assay

AbstractKunitz protease inhibitors (KPIs) are ubiquitous in plants and act as crucial compounds in defense responses against insect attack and pathogen infection. However, the influence of gene duplication on the postdivergence of the CsKPI genes involved in biotic stresses in tea plant is not well known. Here, we identified three CsKPI genes from tea plant (Camellia sinensis) and characterized their expression and evolutionary patterns among plant species. We found that CsKPI1, CsKPI2, and CsKPI3 diverged from their common ancestor 72.94 million years ago (MYA), and the tandem duplication of CsKPI2 and CsKPI3 occurred 26.78 MYA. An in vitro protein assay showed that the three CsKPI proteins were functional and inhibited the production of p-nitroanilide (PNA) from an artificial substrate. The three CsKPI-GFP fusion proteins localized to the cytoplasm. We showed that salicylic acid (SA) and transcripts of CsKPI2 and CsKPI3 significantly accumulated after infection with Glomerella cingulata. The application of exogenous SA stimulated the high expression of both CsKPI2 and CsKPI3 by activating cis-elements within their promoters. Under Ectropis oblique attack, CsKPI1 expression and jasmonic acid (JA) levels were more abundant in both insect-damaged leaf tissues and undamaged neighboring leaves. The application of jasmonic acid methyl ester elicited high expression levels of CsKPI1, suggesting that CsKPI1 accumulation requires JA production in tea plant. The overall findings suggest that the transcriptional divergence of KPI genes after duplication led to the specialized role of CsKPI1 in the physiological response to insect stress; the functional conservation between CsKPI2 and CsKPI3 confers resistance to pathogen infection in tea plant.

Functional characterizations of β-glucosidases involved in aroma compound formation in tea ( Camellia sinensis )

2017 ◽  
Vol 96 ◽  
pp. 206-214 ◽  
Author(s):  
Ying Zhou ◽  
Lanting Zeng ◽  
Jiadong Gui ◽  
Yinyin Liao ◽  
Jianlong Li ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Aroma Compound ◽  
Compound Formation

scholarly journals Utilization of a Gas-Sensing System to Discriminate Smell and to Monitor Fermentation during the Manufacture of Oolong Tea Leaves

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Ting-Shiang Tseng ◽  
Mei-Hui Hsiao ◽  
Po-An Chen ◽  
Shu-Yen Lin ◽  
Shih-Wen Chiu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Critical Factor ◽  
Current Method ◽  
Sensory Function ◽  
Oxide Semiconductor ◽  
Tea Leaves ◽  
Linear Discriminant ◽  
Oolong Tea ◽  
Olfactory Sense ◽  
On Line

The operational duration of shaking tea leaves is a critical factor in the manufacture of oolong tea; this duration influences the formation of its flavor and fragrance. The current method to control the duration of fermentation relies on the olfactory sense of tea masters; they monitor the entire process through their olfactory sense, and their experience decides the duration of shaking and setting. Because of this human factor and olfactory fatigue, it is difficult to define an optimum duration of shaking and setting; an inappropriate duration of shaking and setting deteriorates the quality of the tea. In this study, we used metal-oxide-semiconductor gas sensors to establish an electronic nose (E-nose) system and tested its feasibility. This research was divided into two experiments: distinguishing samples at various stages and an on-line experiment. The samples of tea leaves at various stages exhibited large differences in the level of grassy smell. From the experience of practitioners and from previous research, the samples could be categorized into three groups: before the first shaking (BS1), before the shaking group, and after the shaking group. We input the experimental results into a linear discriminant analysis to decrease the dimensions and to classify the samples into various groups. The results show that the smell can also be categorized into three groups. After distinguishing the samples with large differences, we conducted an on-line experiment in a tea factory and tried to monitor the smell variation during the manufacturing process. The results from the E-nose were similar to those of the sense of practitioners, which means that an E-nose has the possibility to replace the sensory function of practitioners in the future.

scholarly journals Molecular Phylogenetic Diversity and Biological Characterization of Diaporthe Species Associated with Leaf Spots of Camellia sinensis in Taiwan

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1434
Author(s):  
Hiran A. Ariyawansa ◽  
Ichen Tsai ◽  
Jian-Yuan Wang ◽  
Patchareeya Withee ◽  
Medsaii Tanjira ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Leaf Spot ◽  
Phylogenetic Trees ◽  
Fungal Infections ◽  
Elongation Factor ◽  
Fungal Species ◽  
Tea Leaves ◽  
Phenotypic Characters ◽  
Leaf Spots ◽  
Molecular Phylogenetic

Camellia sinensis is one of the major crops grown in Taiwan and has been widely cultivated around the island. Tea leaves are prone to various fungal infections, and leaf spot is considered one of the major diseases in Taiwan tea fields. As part of a survey on fungal species causing leaf spots on tea leaves in Taiwan, 19 fungal strains morphologically similar to the genus Diaporthe were collected. ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α), tub2 (beta-tubulin), and cal (calmodulin) gene regions were used to construct phylogenetic trees and determine the evolutionary relationships among the collected strains. In total, six Diaporthe species, including one new species, Diaporthe hsinchuensis, were identified as linked with leaf spot of C. sinensis in Taiwan based on both phenotypic characters and phylogeny. These species were further characterized in terms of their pathogenicity, temperature, and pH requirements under laboratory conditions. Diaporthe tulliensis, D. passiflorae, and D. perseae were isolated from C. sinensis for the first time. Furthermore, pathogenicity tests revealed that, with wound inoculation, only D. hongkongensis was pathogenic on tea leaves. This investigation delivers the first assessment of Diaporthe taxa related to leaf spots on tea in Taiwan.

scholarly journals Salt and Aroma Compound Distributions Influence Flavour Release and Temporal Perception While Eating Hot-Served Flans

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1300
Author(s):  
Marion Emorine ◽  
Chantal Septier ◽  
Christophe Martin ◽  
Sylvie Cordelle ◽  
Etienne Sémon ◽  
...  
Keyword(s):  
Salt Content ◽  
Optimal Solution ◽  
Proton Transfer Reaction ◽  
Aroma Compounds ◽  
Aroma Compound ◽  
Taste Intensity ◽  
Heterogeneous Distribution ◽  
Flavour Compounds ◽  
Flight Mass Spectrometry

To counteract the negative effect of salt overconsumption on health, strategies have been developed to reduce the salt content in food products. Among them, two promising strategies based on odour-induced saltiness enhancement and the heterogeneous distribution of flavour compounds were combined and assessed in four-layer cream-based snacks. To investigate the relationship between saltiness enhancement, temporal release and perception of flavour compounds in hot snacks with heterogeneous distribution of salt and aroma compounds, complementary techniques were used: nose space PTR-Tof-MS (Proton Transfer Reaction-Time of Flight–Mass Spectrometry) to assess the release of aroma compounds in vivo, and ATI (Alternate Time-Intensity) and TDS Temporal Dominance of Sensations) to evaluate perception as a function of time. The obtained results confirmed that the strategy of concentrating salt in the outer layer of a multilayer product was the optimal solution with respect to taste intensity. Heterogeneous salt distribution decreased aroma compound release and consequently aroma intensity but in different ways according to both salt and added aroma distribution in the food matrix. The salty taste enhancement could be due to the initial strong dominance of the salty sensation at the very beginning of the eating process. The involved mechanisms rely on a combination of physico-chemical and perceptual effects which are not clear yet.

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