摘要：
Phyllosphere microorganisms have recently attracted the attention of scientists studying plant microbiomes. The origin, diversity, functions, and interactions of phyllosphere microorganisms have been extensively explored. Many experiments have demonstrated seasonal cycles of phyllosphere microbes. However, a comprehensive comparison of these separate investigations to characterize seasonal trends in phyllosphere microbes of woody and herbaceous plants has not been conducted. In this review, we explored the dynamic changes of phyllosphere microorganisms in woody and non-woody plants with the passage of the season, sought to find the driving factors, summarized these texts, and thought about future research trends regarding the application of phyllosphere microorganisms in agricultural production. Seasonal trends in phyllosphere microorganisms of herbaceous and woody plants have similarities and differences, but extensive experimental validation is needed. Climate, insects, hosts, microbial interactions, and anthropogenic activities are the diverse factors that influence seasonal variation in phyllosphere microorganisms.
摘要：
High levels of free amino acids (AAs) in tea leaves are crucial for tea flavor and health function; however, the dynamic AA biosynthesis, transport, and turnover in tea plants remain elusive. Here we dissected whole tea plants for these dynamics by assessing AA profiles and transcriptomes of metabolic pathway genes in tea roots, stems, and leaves and revealing their distinctive features with regard to AA synthesis, transport, and degradation/recycling. Nitrogen assimilation dominated in the roots wherein glutamine (Gln), theanine, and arginine (Arg) were actively synthesized. Arg was transported into trunk roots and stems, together with Glu, Gln, and theanine as the major AAs in the xylem sap for long-distance root-to-leaf transport. Transcriptome analysis revealed that genes involved in Arg synthesis were highly expressed in roots, but those for Arg transport and degradation were highly expressed in stems and young leaves, respectively. CsGSIa transcripts were found in root meristem cells, root, stem and leaf vascular tissues, and leaf mesophyll where it appeared to participate in AA synthesis, transport, and recycling. Overexpression of CsGSIa in tea transgenic hairy roots and knockdown of CsGSIa in transgenic hairy roots and tea leaves produced higher and lower Gln and theanine than wild-type roots and leaves, respectively. This study provides comprehensive and new insights into AA metabolism and transport in the whole tea plant.
作者机构：
Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, China;National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China;Hunan Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China;Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops, Ministry of Agriculture and Rural Affairs of China, Hunan Agricultural University, Changsha, China;[Chongxing Li; Linjiang Fang] Lincang City Tea Research Institute, Yunnan Province, Lincang, China
通讯机构：
[Zhonghua Liu; Jianan Huang] K;Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, China<&wdkj&>National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China<&wdkj&>Hunan Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China<&wdkj&>Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops, Ministry of Agriculture and Rural Affairs of China, Hunan Agricultural University, Changsha, China
摘要：
Twenty‐nine compounds were identified as the key volatiles from 237 volatiles, which formed the flowery aroma of PCT. Linalool, geraniol, nonanal, and methyl salicylate were more abundant in the PCT, and they evoked the top five emotions, including mild, wild, aggressive, tame, and bored. Methyl salicylate contributed most to the wild emotion in the two mixed samples, and it may contribute positively to the health effects of tea. Abstract Pu'er crude tea (PCT), the initial raw material for making Pu'er tea, is favored because of unique flavor and health effects. Emotional response is helpful to explain consumers’ choice of different flavors of tea. This study aims to clarify the key floral volatiles of PCT and their emotional impact on people. Twenty‐nine compounds were identified as the key volatiles from 237 volatiles, which formed the flowery aroma of PCT. Linalool, geraniol, nonanal, and methyl salicylate were more abundant in the PCT, they evoked the top five emotions (mild, wild, aggressive, tame, bored). Methyl salicylate contributed most to the wild emotion in the two mixed samples (B10 and B14), and it may contribute positively to the health effects of tea, such as refreshing and anti‐inflammatory. This study provided a preliminary research idea for exploring the relationship between tea aroma and human emotions and its potential role in human health.
关键词：
GC×GC-O-Q-TOMS;Key odorants;Sensory evaluation;‘Baimaocha’ black tea
摘要：
'Baimmaocha' is a distinctive resource for production of high-quality black tea, and its processed black tea has unique aroma characteristics. 190 volatile compounds were identified by comprehensive two-dimensional gas chromatography-olfactometry-quadrupole-time-of-flight mass spectrometry(GC×GC-O-Q-TOMS), and among them 23 compounds were recognized as key odorants contributing to forming different aroma characteristics in 'Baimaocha' black teas of Rucheng, Renhua, and Lingyun (RCBT, RHBT, LYBT). The odor activity value coupled with GC-O showed that methyl salicylate (RCBT), geraniol (RHBT), trans-β-ionone and benzeneacetaldehyde (LYBT) might be the most definitive aroma compounds identified from their respective regions. Furthermore, PLS analysis revealed three odorants as significant contributors to floral characteristic, four odorants related to fruity attribute, four odorants linked to fresh attribute, and three odorants associated with roasted attribute. These results provide novel insights into sensory evaluation and chemical substances of 'Baimaocha' black tea and provide a theoretical basis for controlling and enhancement tea aroma quality.
摘要：
Black tea aroma is composed of volatile flavour compounds at different concentrations generated during the manufacture of black tea. The common process of black tea production consists of four stages: withering, rolling, fermentation, and firing. However, no systematic review and meta-analysis study on the volatile components during black tea processing was conducted. The present study evaluated the changes of the volatile compounds in black tea processing through a systematic review and meta-analytic approach. The results revealed that the content of phenylacetaldehyde and (E)-2-octenal significantly increased during the withering process, which was attributed to glycoside hydrolysis and amino acid reactions. During the rolling process, the content of (E)-2hexenal increased, which may be due to the oxidation of fatty acids. During the fermentation process, the content of phenylacetaldehyde, (E)-2-octenal, and trans-beta-ionone increased through enzymatic and oxidative effects. The withering, rolling, fermentation, and drying processes played crucial roles in the formation of black tea aroma and had significant effects on the key odorants in black tea. These findings provide important insights into optimizing processing parameters in commercial black tea production.
摘要：
Acetylation, a crucial post-translational modification, regulates transcriptional activation, enzymatic activity, and protein interactions, playing vital roles in plant physiology and metabolism. However, the regulatory mechanism of acetylation in the biosynthesis of theanine remains unexplored. This study aims to elucidate the regulatory role of acetylation on the biosynthesis of theanine using transcriptomics, proteomics, and acetylomics in tea leaves from three tea plant cultivars with markedly different theanine content. Nineteen theanine biosynthesis-related genes were identified in the transcriptome, with ten showing significant correlation with theanine content. Proteomic analysis revealed elevated expression levels of proteins associated with the biosynthesis of theanine precursor glutamate in leaves with high theanine content, such as GOGAT and GDH. Unexpectedly, the expression level of TS was inversely correlated with the theanine content in leaves. Several highly expressed acetylated proteins and sites, such as TS, GS, and GOGAT, were found in the acetylome of leaves with high theanine content. Acetylation at lysine 304 (K304) of the TS protein may significantly contribute to the abundant accumulation of theanine in leaves. Our findings indicate that acetylation modification may play a pivotal role in theanine biosynthesis, thereby offering novel insights into the development of high-theanine tea plant germplasm resources.
摘要：
Despite some studies on tea leaf cuticular wax, their component changes during dehydration and withering treatments in tea processing and suspected relation with tea flavor quality formation remain unknown. Here, we showed that tea leaf cuticular wax changed drastically in tea leaf development, dehydration, or withering treatment during tea processing, which affected tea flavor formation. Caffeine was found as a major component of leaf cuticular wax. Caffeine and inositol contents in leaf cuticular wax increased during dehydration and withering treatments. Comparisons showed that tea varieties with higher leaf cuticular wax loading produced more aroma than these with lower cuticular wax loading, supporting a positive correlation between tea leaf cuticular wax loading and degradation with white tea aroma formation. Dehydration or withering treatment of tea leaves also increased caffeine and inositol levels in leaf cuticular wax and triggered cuticular wax degradation into various molecules, that could be related to tea flavor formation. Thus, tea leaf cuticular waxes not only protect tea plants but also contribute to tea flavor formation. The study provides new insight into the dynamic changes of tea leaf cuticular waxes for tea plant protection and tea flavor quality formation in tea processing.
摘要：
Theanine is a unique secondary metabolite in tea plants and contributes to the umami taste and health benefits of tea. However, theanine biosynthesis in tea plants is not fully understood, and its mechanism of transcriptional regulation remains poorly reported. Theanine content was significantly correlated with the expression of theanine biosynthesis-related gene CsGS1c and transcription factor CsMYB42 in different leaf positions and picking times, but there was no significant correlation in different tissues of albino tea plant 'Anjibaicha'. This suggests that CsMYB42 may regulate CsGS1c to synthesize theanine in albino tea leaves, and the regulation is tissue specific. CsMYB42 is a nuclear-localized R2R3-MYB transcription factor gene with transcriptional activation activity. Yeast one-hybrid assay and electrophoretic mobility shift assay confirmed the direct binding of CsMYB42 to the promoter of CsGS1c. Luciferase assay showed that CsMYB42 activates the CsGS1c expression. Furthermore, the inhibition of CsMYB42 using an antisense oligonucleotide in tea leaves decreased CsGS1c expression and theanine content. These results indicate that CsMYB42 plays a crucial role in activating the expression of CsGS1c and may be involved in the biosynthesis of theanine in albino tea leaves. This study provides fresh insights into the tissue-specific regulation of theanine biosynthesis, which laid a foundation for breeding high-theanine tea plants.
期刊：
Food Research International,2023年168:112759 ISSN：0963-9969
通讯作者：
Li, Xinghui(lxh@njau.edu.cn)
作者机构：
[Zhao, Zhen; Jeyaraj, Anburaj; Zhuang, Jing; Wang, Yuhua; Liu, Zhonghua; Chen, Xuan; Li, Jianjie; Li, Xinghui; He, Youyue; Mei, Huiling] Nanjing Agr Univ, Int Inst Tea Ind Innovat the Belt & Rd, Nanjing 210095, Peoples R China.;[Liu, Zhonghua] Hunan Agr Univ, Natl Res Ctr Engn & Technol Utilizat Bot Funct Ing, Changsha 410128, Peoples R China.;[Liu, Zhonghua] Hunan Agr Univ, Key Lab Tea Sci, Minist Educ, Changsha 410128, Peoples R China.
通讯机构：
[Xinghui Li; Zhonghua Liu] I;International Institute of Tea Industry Innovation for “the Belt and Road”, Nanjing Agricultural University, Nanjing 210095, China<&wdkj&>International Institute of Tea Industry Innovation for “the Belt and Road”, Nanjing Agricultural University, Nanjing 210095, China<&wdkj&>National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
摘要：
Spreading is an indispensable process in the aroma formation of green tea. The application of exogenous red-light spreading in tea processing has been verified to significantly improve the aroma of green tea, and endow tea with freshness, sweet flavor, and mellow taste. However, there were no previous studies investigating the effects of spreading with different red-light intensities on the aroma components of green tea. The aim of the present study was to evaluate the effect of the relationship between the aroma component and spreading with different red-light intensities (300 mu mol center dot m(-2)center dot s(-1), 150 mu mol center dot m(-2)center dot s(-1) and 75 mu mol center dot m(-2)center dot s(-1)). As a result, a total of ninety-one volatile components were identified in this study. The orthogonal partial least squares discriminant analysis (OPLS-DA) model clearly distinguished the volatile components of green tea between different red-light intensities and obtained thirty-three differential volatile compounds. Combined with odor activity value (OAV > 1) analysis revealed that eleven volatile components were the key volatile compounds of green tea under different light conditions. Among them, 3-methyl-butanal, (E)-nerolidol, and linalool were the sources of chestnut-like aroma in green tea and were significantly accumulated under medium (MRL) and low intensity (LRL) red light. The results of the present study provided a theoretical basis that could guide green tea processing with red-light intensities to increase the aroma quality components of green tea.
通讯机构：
[Jian Zhao] S;State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University , Hefei 230036, China<&wdkj&>Key Laboratory of Tea Science of Ministry of Education, College of Horticulture, Hunan Agricultural University , Changsha 410128, China
摘要：
Stomata perform important functions in plant photosynthesis, respiration, gas exchange, and interactions with environments. However, tea plant stomata development and functions are not known. Here, we show morphological changes during stomata development and genetic dissection of stomata lineage genes regulating stomata formation in tea developing leaves. Different tea plant cultivars displayed clear variations in the stomata development rate, density and size, which are closely related to their tolerance against dehydration capabilities. Whole sets of stomata lineage genes were identified to display predicted functions in regulating stomatal development and formation. The stomata development and lineage genes were tightly regulated by light intensities and high or low temperature stresses, which affected stomata density and function. Furthermore, lower stomatal density and larger size were observed in triploid tea varieties as compared to those in diploid plant. Key stomata lineage genes such as CsSPCHs, CsSCRM, and CsFAMA showed much lower expression levels, whereas negative regulators CsEPF1 and CsYODAs had higher expression levels in triploid than in diploid tea varieties. Our study provides new insight into tea plant stomatal morphological development and the genetic regulatory mechanisms on stomata development under abiotic stresses and genetic backgrounds. The study lays a foundation for future exploring of the genetic improvement of water use efficiency in tea plants for living up to the challenge of global climate change.
作者机构：
[欧阳建; 彭忠; 刘洋; 李娟; 王英姿; 李适; 黄建安; 刘仲华; 欧行畅] National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Key Lab of Education Ministry of Hunan Agricultural University for Tea Science, Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Changsha, 410128, China;[黄纯勇] Xiangnong University Tea Industry Research Institute, Xiangxi, 416099, China
通讯机构：
[Liu, Z.; Huang, J.] N;National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, China
通讯机构：
[Zou, X.] L;[Qin, C.] E;Engineering Research Center of Zunyi Pepper Germplasm Resources Conservation and Breeding Cultivation of Guizhou Province, China;Longping Branch, China
摘要：
Ovate family proteins (OFPs) are transcriptional inhibitors that regulate plant growth and development and play important roles in the synthesis of secondary cell walls during pollen development. This study identified the pepper OFP gene family based on the genome-wide analysis and used bioinformatics methods to provide a fundamental profile of the gene family. 74 OFP genes with typical Ovate domain were identified in cultivated pepper Zunla-1, wild pepper Chiltepin and CM334. Chromosome mapping revealed that CazOFP genes were unevenly distributed on 11 chromosomes and Chr00 in Zunla-1, CacOFP genes on 12 chromosomes in Chiltepin, and CamOFP genes on 12 chromosomes and two Scaffflods in CM334. Gene structure analysis revealed that CaOFP genes possessed 1-3 exons, and the analysis of physicochemical properties suggested that CaOFPs were hydrophilic. Many cis-acting elements were identified in the promoter region of CaOFP genes, including ABRE, ARE, Box 4, G-box, TC-rich, and TCT-motif. The expression patterns of pepper at different growth stages showed that CaOFP genes were actively involved in the growth and fruit development of pepper, and CazOFP16 and CazOFP17 were actively involved in response to multiple hormones and stress events. qRT-PCR was also used to verify the expression of CazOFP gene in two developmental stages of seven pepper varieties with different fruit shapes, and it was found that CaOFP genes may be involved in the formation of fruit type in pepper. This study provides theoretical and practical evidence for future research on the OFP gene family.
