Preparation and Physicochemical Analysis of Camellia sinensis cv. 'Ziyan' Anthocyanin Microcapsules.

The new tea cultivar Ziyan has a high content of anthocyanin and ester catechins in the raw material, but the conventional processing and application methods are limited. To explore its application potential, the freeze-drying method was used to prepare microcapsules with an embedding time of 30 min, solid content of 30%, and core to wall ratio of 1:10 (g/g). The anthocyanin recovery was 95.94 ± 0.50%, and the encapsulation efficiency was 96.15 ± 0.11%. The stability of microcapsules and composite wall materials was evaluated in the simulation system. Results showed that microcapsules employing a maltodextrin-gum arabic ratio of 2:8 (w/w) as the wall material significantly reduced degradation rates, extending anthocyanin half-life under various storage conditions. Characterization indicated improved physical properties of Ziyan anthocyanin powder post-microencapsulation. FT-IR and DSC- revealed the formation of a new phase between anthocyanins and wall materials, leading to increased enthalpy and enhanced thermal stability. The microencapsulation results of this experiment proved that the storage stability of anthocyanin was effectively enhanced.

Genome-Wide Analysis of Nuclear factor-YC Genes in the Tea Plant (Camellia sinensis) and Functional Identification of CsNF-YC6.

Nuclear factor Y (NF-Y) is a class of transcription factors consisting of NF-YA, NF-YB and NF-YC subunits, which are widely distributed in eukaryotes. The NF-YC subunit regulates plant growth and development and plays an important role in the response to stresses. However, there are few reports on this gene subfamily in tea plants. In this study, nine CsNF-YC genes were identified in the genome of 'Longjing 43'. Their phylogeny, gene structure, promoter cis-acting elements, motifs and chromosomal localization of these gene were analyzed. Tissue expression characterization revealed that most of the CsNF-YCs were expressed at low levels in the terminal buds and at relatively high levels in the flowers and roots. CsNF-YC genes responded significantly to gibberellic acid (GA) and abscisic acid (ABA) treatments. We further focused on CsNF-YC6 because it may be involved in the growth and development of tea plants and the regulation of response to abiotic stresses. The CsNF-YC6 protein is localized in the nucleus. Arabidopsis that overexpressed CsNF-YC6 (CsNF-YC6-OE) showed increased seed germination and increased root length under ABA and GA treatments. In addition, the number of cauline leaves, stem lengths and silique numbers were significantly higher in overexpressing Arabidopsis lines than wild type under long-day growth conditions, and CsNF-YC6 promoted primary root growth and increased flowering in Arabidopsis. qPCR analysis showed that in CsNF-YC6-OE lines, flowering pathway-related genes were transcribed at higher levels than wild type. The investigation of the CsNF-YC gene has unveiled that CsNF-YC6 plays a pivotal role in plant growth, root and flower development, as well as responses to abiotic stress.

Insights into momentous aroma dominating the characteristic flavor of jasmine tea.

Jasmine tea is loved by most people who drink flower tea owing to its unique aroma, and it is known as the top of flower teas. In our study, the quantitative evaluation of the quality of jasmine tea and detection of aroma components were carried out. First, the flavor quality of 92 kinds of jasmine tea was evaluated using multiple sub-factor quality evaluation methods. According to the evaluation results, jasmine tea was divided into three types: "fresh and lovely" (FL), "heavy and thick" (HT), and "fresh and heavy" (FH). Gas chromatography-mass spectrometry (GC-MS) was used to detect the aroma components of the three types of jasmine tea samples. α-Farnesene, cis-3-hexenyl benzoate, acid phenylmethyl ester, linalool, methyl anthranilate, and indole were the main substances that constituted the basic aroma quality characteristics of jasmine tea. Compared to the FL type, the HT and FH types were weaker in the diversification of the characteristic aroma and accumulation of green, herb, sweet, and roast aroma substances. Green and herb aromas play crucial roles in the fresh and persistent qualities of the three types of jasmine tea, which are the key quality factors research focus of jasmine tea.

Untargeted metabolomics and quantification analysis reveal the shift of chemical constituents between instant dark teas individually liquid-state fermented by Aspergillus cristatus, Aspergillus niger, and Aspergillus tubingensis.

Instant dark teas (IDTs) were individually liquid-state fermented using the fungi Aspergillus cristatus, Aspergillus niger, and Aspergillus tubingensis. To understand how the chemical constituents of IDTs were affected by the fungi, samples were collected and measured by liquid chromatography-tandem mass-tandem mass spectrometry (LC-MS/MS). Untargeted metabolomics analysis revealed that 1,380 chemical constituents were identified in positive and negative ion modes, and 858 kinds of chemical components were differential metabolites. Through cluster analysis, IDTs were different from the blank control, and their chemical constituents mostly included carboxylic acids and their derivatives, flavonoids, organooxygen compounds, and fatty acyls. And the metabolites of IDTs fermented by A. niger and A. tubingensis had a high degree of similarity and were classified into one category, which showed that the fungus used to ferment is critical to the formation of certain qualities of IDTs. The biosynthesis of flavonoids and phenylpropanoid, which involved nine different metabolites such as p-coumarate, p-coumaroyl-CoA, caffeate, ferulate, naringenin, kaempferol, leucocyanidin, cyanidin, and (-)-epicatechin, were significant pathways influencing the quality formation of IDTs. Quantification analysis indicated that the A. tubingensis fermented-IDT had the highest content of theaflavin, theabrownin, and caffeine, while the A. cristatus fermented-IDT had the lowest content of theabrownin, and caffeine. Overall, the results provided new insights into the relationship between the quality formation of IDTs and the microorganisms used in liquid-state fermentation.

Dynamic changes in the diversity and function of bacterial community during black tea processing.

Among all types of tea, black tea is produced in the largest amount worldwide, and its consumption is still increasing. Enzymatic fermentation is considered majorly contribute to quality formation of black tea, and the information about the roles of bacterial community in black tea processing is scarce. This study aimed to analyze the dynamic changes in composition, structure, and function of microbial communities during black tea processing and reveal the roles of bacterial community in black tea processing. Results showed that the genera Sphingomonas and Variovorax were dominant throughout the processing of black tea. Prediction function analysis of bacterial community showed that the mean proportions of glucuronoarabinoxylan endo - 1,4 - beta - xylanase, aminopeptidase B, phosphoserine phosphatase, homoserine O-acetyltransferase, glycolysis related enzymes, pyruvate dehydrogenase, tricarboxylic acid cycle related enzymes, and glyoxylate bypass were significantly elevated in the rolling and fermentation stages. The contents of amino acids, soluble sugar, theaflavins, thearubigins, and theabrownins increased greatly during the rolling and fermentation processes. Redundancy and Pearson's correlation analyses showed that the relative abundance of bacteria was closely related to the contents of water extract, tea polyphenols, epigallocatechin, epicatechin gallate, catechin gallate, thearubigins, theaflavins, and theabrownins. Overall, the findings provided new insights into the variation of bacterial community during black tea processing and improved our understanding of the core functional bacteria involved in black tea processing.

Microbial Community Analysis in Sichuan South-road Dark Tea Piled Center at Pile-Fermentation Metaphase and Insight Into Organoleptic Quality Development Mediated by Aspergillus niger M10.

Microbes are critical in the Sichuan South-road Dark Tea (SSDT) organoleptic quality development during pile-fermentation. Piled tea center at fermenting metaphase is crucial for the conversion of its quality components. In this study, we investigated the microbial community of piled SSDT center below the stacked tea surface of 15 cm (SSDTB), 50 cm (SSDTX), and 85 cm (SSDTH) on the second turning time of pile-fermentation, respectively. Results showed that SSDTH and SSDTB had a higher similarity in the microbial community. Pantoea (36.8%), Klebsiella (67.7%), and Aspergillus (35.3%) were the most abundant in SSDTH, SSDTB, and SSDTX, respectively. We found 895 species were common among all samples, but 86, 293, and 36 species were unique to SSDTB, SSDTX, and SSDTH, respectively. Aspergillus niger showed high co-occurrence and was positively correlated with numerous microbes in SSDT samples, and Aspergillus niger M10 isolated from SSDTX was excellent at enhancing soluble sugar (SS), amino acids (AAs), theaflavin (TF), and thearubigins (TR) contents, while decreasing catechin (Cat), tea polyphenols (TPs)/AA, Caf/SS, Cat/SS, TPs/SS, and (TPs + Caf)/SS levels in AM10 post-fermentation, as compared with the control. Moreover, it also produced a noticeable difference in the CIELab parameters in dried, liquor, and infused tea colors between AM10 and control during fermentation. When it was further inoculated on differential mediums, we detected glycoside hydrolases, namely, ß-glucosidase, mannosidase, pectinase, cellulase, amylase, and α-galactosidase being secreted by Aspergillus niger M10. Taken together, SSDXT presented a more unique microbial community. Aspergillus niger M10 probably improved the sweet and mellow taste, and the yellow brightness and red color of SSDT during fermentation. It also provided new insights into the microbial profile and organoleptic quality development mechanism of SSDT during pile-fermentation.

Genetic analysis of the early bud flush trait of tea plants (Camellia sinensis) in the cultivar 'Emei Wenchun' and its open-pollinated offspring.

The timing of bud flush (TBF) in the spring is one of the most important agronomic traits of tea plants (Camellia sinensis). In this study, we designed an open-pollination breeding program using 'Emei Wenchun' (EW, a clonal tea cultivar with extra-early TBF) as a female parent. A half-sib population (n = 388) was selected for genotyping using specific-locus amplified fragment sequencing. The results enabled the identification of paternity for 294 (75.8%) of the offspring, including 11 (2.8%) from EW selfing and 217 (55.9%) assigned to a common father, 'Chuanmu 217' (CM). The putative EW × CM full-sib population was used to construct a linkage map. The map has 4244 markers distributed in 15 linkage groups, with an average marker distance of 0.34 cM. A high degree of collinearity between the linkage map and physical map was observed. Sprouting index, a trait closely related to TBF, was recorded for the offspring population in 2020 and 2021. The trait had moderate variation, with coefficients of variation of 18.5 and 17.6% in 2020 and 2021, respectively. Quantitative trait locus (QTL) mapping that was performed using the linkage map identified two major QTLs and three minor QTLs related to the sprouting index. These QTLs are distributed on Chr3, Chr4, Chr5, Chr9, and Chr14 of the reference genome. A total of 1960 predicted genes were found within the confidence intervals of QTLs, and 22 key candidate genes that underlie these QTLs were preliminarily screened. These results are important for breeding and understanding the genetic base of the TBF trait of tea plants.

The complete mitochondrial genome of a tea bagworm, Mahasena colona (Lepidoptera: Psychidae).

The mitochondrial genome of Mahasena colona Sonan has been sequenced and annotated completely. The entire genome is 16,119 bp in length with an A + T content of 82.85% (GenBank accession No. KY856825). The tea bagworm mt genome encodes all 37 genes that are typically found in animal mt genomes, consists of 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. Within the mt genome of M. colona, there are six gene reading frame overlaps. The gene order is consistent with other sequenced mt genome of moths and butterflies in Ditrysia. The mt genome of M. colona contains a 728 bp A + T-rich region with a high A + T content of 97.66%.

The complete mitochondrial genome of a tea geometrid, Ectropis obliqua (Lepidoptera: Geometridae).

The tea geometrid, Ectropis obliqua Prout (Lepidoptera: Geometridae), is a major pest of tea plantation and poses a considerable economic threat to tea industry. We have sequenced the complete mitochondrial genome of E. obliqua. The entire genome is 16,535 bp in length with an A + T content of 81.32% (GenBank accession No. KX827002). The tea geometrid mt genome encodes all 37 genes that are typically found in animal mt genomes, consists of 13 protein-coding genes (PCG), two ribosomal RNA genes, and 22 transfer RNA genes. The gene order is consistent with other sequenced mt genome of moths and butterflies in Ditrysia. The A + T-rich region is 1523 bp long and consisting of the motif 'ATAGA', a 19 bp poly-T stretch, and a tandem repeat sequence with seven 194 bp repeat units. Phylogenetic analysis was performed using 13 PCG with 16 moths showed that E. obliqua clusters with other Geometridae species.

The complete mitochondrial genome of the tea lace bug, Stephanitis chinensis (Hemiptera: Tingidae).

The tea lace bug, Stephanitis chinensis Drake (Hemiptera: Tingidae), is a pest which feeds on the undersides of tea leaves by piercing the epidermis and sucking the sap, and causes great harm to plant growth and tea production. We have obtained the whole mitochondrial genome of S. chinensis (GenBank accession No. MF498769). The entire mt genome is 16,667 bp in size with an A + T content of 78.41%. The tea lace bug mt genome encodes all 37 genes that are typically found in animal mt genomes, consists of 13 protein-coding genes (PCGs), 2 ribosomal RNA, and 22 transfer RNA genes. The gene order is consistent with other sequenced mt genome of lace bugs. The A + T-rich region of this genome is 2215 bp long with the A + T content of 82.58%, and located between the rrnS and trnI genes. Phylogenetic analysis performed using 13 PCGs with 14 heteropteran insects showed that S. chinensis clusters with other Tingidae species.

The Complete Mitochondrial Genome of Aleurocanthus camelliae: Insights into Gene Arrangement and Genome Organization within the Family Aleyrodidae.

There are numerous gene rearrangements and transfer RNA gene absences existing in mitochondrial (mt) genomes of Aleyrodidae species. To understand how mt genomes evolved in the family Aleyrodidae, we have sequenced the complete mt genome of Aleurocanthus camelliae and comparatively analyzed all reported whitefly mt genomes. The mt genome of A. camelliae is 15,188 bp long, and consists of 13 protein-coding genes, two rRNA genes, 21 tRNA genes and a putative control region (GenBank: KU761949). The tRNA gene, trnI, has not been observed in this genome. The mt genome has a unique gene order and shares most gene boundaries with Tetraleurodes acaciae. Nineteen of 21 tRNA genes have the conventional cloverleaf shaped secondary structure and two (trnS1 and trnS2) lack the dihydrouridine (DHU) arm. Using ARWEN and homologous sequence alignment, we have identified five tRNA genes and revised the annotation for three whitefly mt genomes. This result suggests that most absent genes exist in the genomes and have not been identified, due to be lack of technology and inference sequence. The phylogenetic relationships among 11 whiteflies and Drosophila melanogaster were inferred by maximum likelihood and Bayesian inference methods. Aleurocanthus camelliae and T. acaciae form a sister group, and all three Bemisia tabaci and two Bemisia afer strains gather together. These results are identical to the relationships inferred from gene order. We inferred that gene rearrangement plays an important role in the mt genome evolved from whiteflies.

The Dark-Purple Tea Cultivar 'Ziyan' Accumulates a Large Amount of Delphinidin-Related Anthocyanins.

Recently, we developed a novel tea cultivar 'Ziyan' with distinct purple leaves. There was a significant correlation between leaf color and anthocyanin pigment content in the leaves. A distinct allocation of metabolic flow for B-ring trihydroxylated anthocyanins and catechins in 'Ziyan' was observed. Delphinidin, cyanidin, and pelargonidin (88.15 mg/100 g FW in total) but no other anthocyanin pigments were detected in 'Ziyan', and delphinidin (70.76 mg/100 g FW) was particularly predominant. An analysis of the catechin content in 'Ziyan' and eight other cultivars indicated that 'Ziyan' exhibits a preference for synthesizing B-ring trihydroxylated catechins (with a proportion of 74%). The full-length cDNA sequences of flavonoid pathway genes were isolated by RNA-Seq coupled with conventional TA cloning, and their expression patterns were characterized. Purple-leaved cultivars had lower amounts of total catechins, polyphenols, and water extract than ordinary non-anthocyanin cultivars but similar levels of caffeine. Because dark-purple-leaved Camellia species are rare in nature, this study provides new insights into the interplay between the accumulations of anthocyanins and other bioactive components in tea leaves.

The complete mitogenome of Jankowskia athleta (Lepidoptera: Geometridae).

We have sequenced the entire mitochondrial genome of Jankowskia athleta, that is 15 534 bp in length with a 79.53% A + T content (GenBank accession no. KR822683). The mt genome of J. athleta encodes 37 genes that are typically found in metazoan mt genomes, consists of 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. Within the mt genome of J. athleta, there are six gene reading frame overlaps. The gene order is consistent with other yet sequenced mt genome in Geometridae. The mt genome of J. athleta has a 475 bp A + T-rich region with an A + T content of 93.47%. The result of phylogenetic analysis infers that J. athleta is more closely related to species of Geometridae than other moths.