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Mechanization is the inevitable future of tea harvesting, but its impact on tea chemistry and quality remains uncertain. Our study examines untargeted metabolomic data from 185 oolong tea products (Tieguanyin) made from leaves harvested by hand or machine based on UPLC-QToF-MS analysis. The data revealed a minimum 50% loss for over half of the chemicals in the machine-harvested group, including catechins, theaflavin, gallic acid, chlorogenic acid, and kaempferol-3-gluocside. Integrating sensory evaluation, OPLS-DA identified the six most important metabolites as significant contributors to sensory decline caused by harvesting mechanization. Furthermore, our research validates the possibility of using DD-SIMCA modelling with untargeted metabolomic data for distinguishing handpicked from machine-harvested tea products. The model was able to achieve 93% accuracy. This study provides crucial insights into the chemical and sensory shifts during mechanization, along with tools to manage and monitor these changes. [ABSTRACT FROM AUTHOR]

Gray blight disease, which is caused by Pestalotiopsis-like species, poses significant challenges to global tea production. However, the comprehensive metabolic responses of tea plants during gray blight infection remain understudied. Here, we employed a multi-omics strategy to characterize the temporal transcriptomic and metabolomic changes in tea plants during infection by Pseudopestalotiopsis theae, the causal agent of gray blight. Untargeted metabolomic profiling with ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) revealed extensive metabolic rewiring over the course of infection, particularly within 24 h post-inoculation. A total of 64 differentially accumulated metabolites were identified, including elevated levels of antimicrobial compounds such as caffeine and (−)-epigallocatechin 3-gallate, as well as oxidative catechin polymers like theaflavins, theasinensins and theacitrins. Conversely, the synthesis of (+)-catechin, (−)-epicatechin, oligomeric proanthocyanidins and flavonol glycosides decreased. Integrated omics analyses uncovered up-regulation of phenylpropanoid, flavonoid, lignin biosynthesis and down-regulation of photosynthesis in response to the pathogen stress. This study provides novel insights into the defense strategies of tea plants against gray blight disease, offering potential targets for disease control and crop improvement. [ABSTRACT FROM AUTHOR]

Camellia seed oil is a top-end quality of cooking oil in China. The oil quality and quantity are formed during seed maturation and desiccation. So far, it remains largely unresolved whether lipid degradation occurs and contributes to Camellia oil traits. In this study, three different Camellia germplasms, C. oleifera cv. Min 43 (M43), C. meiocarpa var. Qingguo (QG), and C. meiocarpa cv Hongguo (HG) were selected, their seed oil contents and compositions were quantified across different stages of seed desiccation. We found that at the late stage of desiccation, M43 and QG lost a significant portion of seed oil, while such an event was not observed in HG. To explore the molecular bases for the oil loss In M43, the transcriptomic profiling of M43 and HG was performed at the early and the late seed desiccation, respectively, and differentially expressed genes (DEGs) from the lipid metabolic pathway were identified and analyzed. Our data demonstrated that different Camellia species have diverse mechanisms to regulate seed oil accumulation and degradation, and that triacylglycerol-to-terpenoid conversion could account for the oil loss in M43 during late seed desiccation. [ABSTRACT FROM AUTHOR]

The design and construction of semiconductor–metal heterojunctions are being considered to be an effective way to overcome the limited visible-light absorption of semiconductors. Herein, a facile and scale approach is reported for the first time to synthesize Cu/ZnO heterojunctions by one-step galvanic replacement between Zn and cuprous solution reaction. Two kinds of morphologies Cu/ZnO heterojunctions could be obtained by changing cuprous salt anion such as Br−, Cl− and I−. A flower-like Cu/ZnO heterostructured is chosen as a representative to demonstrate the facility and enhanced photocatalytic performance toward Rhodamine B degradation under visible-light irradiation. Results showed flower-like Cu/ZnO heterojunctions have higher photocatalytic performance than the other two morphologies. The galvanic replacement growth mechanism of Cu/ZnO heterojunctions was also further investigated. It is found that Cu/ZnO heterojunctions formed from Zn and Cu2O at an acid solution and room condition. This work indicates that galvanic replacement reaction at room temperature is an excellent technique to grow Cu/ZnO heterojunctions and demonstrates that the hole and electron transfer between Cu and ZnO can efficiently enhance their photocatalytic performance. This general method can also be further explored to guide the design of metal/metal oxide heterostructured on other substrates, such as Zn, Ni and Cu foils. Scale Cu/ZnO heterojunctions were synthesized by one-step galvanic replacement approach. Different morphologies of Cu/ZnO heterojunctions can be obtained by changing cuprous salt anion. The photocatalytic degradation of rhodamine B (RhB) over Cu/ZnO heterojunctions under visible light irradiation was investigated in this study, RhB (0.02 mM/L) was almost completely decolorized in given conditions. This general method can also be further explored to guide the design of metal/metal oxide heterostructures on other substrates. [ABSTRACT FROM AUTHOR]

The cuticle plays a major role in restricting nonstomatal water transpiration in plants. There is therefore a long-standing interest to understand the structure and function of the plant cuticle. Although many efforts have been devoted, it remains controversial to what degree the various cuticular parameters contribute to the water transpiration barrier. In this study, eight tea germplasms were grown under normal conditions; cuticle thickness, wax coverage, and compositions were analyzed from the epicuticular waxes and the intracuticular waxes of both leaf surfaces. The cuticular transpiration rates were measured from the individual leaf surface as well as the intracuticular wax layer. Epicuticular wax resistances were also calculated from both leaf surfaces. The correlation analysis between the cuticular transpiration rates (or resistances) and various cuticle parameters was conducted. We found that the abaxial cuticular transpiration rates accounted for 64–78% of total cuticular transpiration and were the dominant factor in the variations for the total cuticular transpiration. On the adaxial surface, the major cuticular transpiration barrier was located on the intracuticular waxes; however, on the abaxial surface, the major cuticular transpiration barrier was located on the epicuticular waxes. Cuticle thickness was not a factor affecting cuticular transpiration. However, the abaxial epicuticular wax coverage was found to be significantly and positively correlated with the abaxial epicuticular resistance. Correlation analysis suggested that the very-long-chain aliphatic compounds and glycol esters play major roles in the cuticular transpiration barrier in tea trees grown under normal conditions. Our results provided novel insights about the complex structure–functional relationships in the tea cuticle. [ABSTRACT FROM AUTHOR]

The cuticle is regarded as a non-living tissue; it remains unknown whether the cuticle could be reversibly modified and what are the potential mechanisms. In this study, three tea germplasms (Wuniuzao , 0202-10 , and 0306A) were subjected to water deprivation followed by rehydration. The epicuticular waxes and intracuticular waxes from both leaf surfaces were quantified from the mature 5th leaf. Cuticular transpiration rates were then measured from leaf drying curves, and the correlations between cuticular transpiration rates and cuticular wax coverage were analyzed. We found that the cuticular transpiration barriers were reinforced by drought and reversed by rehydration treatment; the initial weak cuticular transpiration barriers were preferentially reinforced by drought stress, while the original major cuticular transpiration barriers were either strengthened or unaltered. Correlation analysis suggests that cuticle modifications could be realized by selective deposition of specific wax compounds into individual cuticular compartments through multiple mechanisms, including in vivo wax synthesis or transport, dynamic phase separation between epicuticular waxes and the intracuticular waxes, in vitro polymerization, and retro transportation into epidermal cell wall or protoplast for further transformation. Our data suggest that modifications of a limited set of specific wax components from individual cuticular compartments are sufficient to alter cuticular transpiration barrier properties. [ABSTRACT FROM AUTHOR]

Aroma is one of the key sensory attributes of tea. Quantitative volatile measurement is essential but technically challenging. Sample extraction is the first critical step for quantification. However, volatile extraction method has not been systematically optimized. The goal of this research was to establish a quantitative volatile measurement method in tea. For this end, solvent‐assisted flavour evaporation method was used; the effects of the numbers of extraction, stirring, sample amounts, solid–liquid ratios and postharvest treatments on volatile isolation were compared. We demonstrated that stirring did not improve total volatile recovery; the number of volatiles detected was positively correlated with sample amounts and the solid–liquid ratio, excess sample amounts compromised the quantification accuracy of abundant volatiles; cryopreservation largely preserved the volatile contents and composition of fresh tea leaves. Based on these findings, volatile extraction method was optimized. The volatile compounds were qualitatively and quantitatively analysed by GC‐MS and GC‐FID, respectively; the FID relative response factor for individual volatile was calculated to calibrate individual peak area of tea volatile. By integrating these techniques, a quantitative volatile measurement method was established. As a proof of concept, the described method was applied to investigate the seasonal effects on fresh tea leaf volatile. The described method should also be applicable to other horticultural crop species. [ABSTRACT FROM AUTHOR]

The plant cuticle is the major barrier that limits unrestricted water loss and hence plays a critical role in plant drought tolerance. Due to the presence of stomata on the leaf abaxial surface, it is technically challenging to measure abaxial cuticular transpiration. Most of the existing reports were only focused on leaf astomatous adaxial surface, and few data are available regarding abaxial cuticular transpiration. Developing a method that can measure cuticular transpiration from both leaf surfaces simultaneously will improve our understanding about leaf transpiration barrier organization. Here, we developed a new method that enabled the simultaneous measurement of cuticular transpiration rates from the adaxial and abaxial surfaces. The proposed method combined multi-step leaf pretreatments including water equilibration under dark and ABA treatment to close stomata, as well as gum arabic or vaseline application to remove or seal the epicuticular wax layer. Mathematical formulas were established and used to calculate the transpiration rates of individual leaf surfaces from observed experimental data. This method facilitates the simultaneous quantification of cuticular transpiration from adaxial and abaxial leaf surfaces. By applying this method, we demonstrated that the adaxial intracuticular waxes and the abaxial epicuticular waxes constitute the major transpiration barriers in Camellia sinensis. Wax analysis indicated that adaxial intracuticular waxes had higher coverage of very long chain fatty acids, 1-alkanol esters, and glycols, which may be attributed to its higher transpiration barrier than that of the abaxial intracuticular waxes. [ABSTRACT FROM AUTHOR]

Lipid droplets (LDs) have been widely found from diverse species and exhibit diverse functions. It remains unexplored what potential roles they played in tea. To address this question, we analyzed the chemical composition and the dynamic changes of cytosolic LDs during leaf growth and diurnal cycle. Using TopFluor cholesterol and Nile Red staining we demonstrated that cytosolic LDs were heterogeneous in tea tree (Camellia sinensis cv. Tieguanyin); the size and number of LDs increased with leaf growth. Compositional analysis showed that terpenoid esters and diacylglycerol are the major components of cytosolic LDs. The contents of total sterol esters (SEs) and β-amyrin esters increased with leaf expansion and growth; individual SE also showed diurnal changes. Our data suggest that cytosolic LDs from tea tree leave mainly serve as storage site for free sterols and triterpenoids in the form of esters. Cytosolic LDs were not the major contributors to the aroma quality of made tea. [ABSTRACT FROM AUTHOR]

• Self-supporting ternary alloy catalyst was prepared by one step growth. • The principle of interface reaction at the atomic level. • Excellent HER properties attributed to ternary alloy catalysts structure. Active electrocatalysts are the key of water splitting for hydrogen production through the electrolysis. In this paper, Ni foams substrates as templates, self-supporting ternary alloy catalyst was prepared by one step at room temperature. Growth mechanism of self-supporting ternary alloy catalyst is explored by growth process. Micro-current technology of galvanic reaction and the principle of interface electric double layer reaction are important to the self-supporting ternary alloy catalyst. Their catalytic activity was evaluated by electrocatalytic hydrogen evolution(HER). It exhibits excellent HER properties with a overpotential (17 mV) and small Tafel slope (10.2 mVdec−1). Their enhanced performances in HER catalysts can be mainly attributed to ternary alloy catalysts structure, which allows the appearance synergistic effects and larger specific surface area. This research is to control the micro-area of chemical reaction at the atomic level by non-precious template and all kinds of precursor mixture solution. Self-supporting ternary alloy catalyst was prepared by one-step galvanic replacement. They display exerlent superior activity for the HER in base solution with an onset reduction potential of + 17 mV vs RHE and small Tafel slope (10.2 mVdec−1). This activity is due to the synergistic effects and larger specific surface area. [Display omitted]. [ABSTRACT FROM AUTHOR]

• 38 volatile compounds were identified from four ripening stages of papaya fruit. • Each aroma showed specific changing trends during fruit ripening. • Correlation analysis identified putative genes for specific aroma biosynthesis. The purpose of this research was to quantify volatile compound changes during papaya fruit ripening and to identify putative genes that are responsible for aroma synthesis. Volatile compounds at four different stages of fruit ripening were isolated from 'Hong fei' variety by solvent assisted flavor evaporation, then analyzed by gas chromatography-mass spectrometry. In total, 38 different volatile compounds were identified, including terpenes, esters, lactones, ketones, alcohols, aldehydes, volatile acids, S- and N- containing compounds, and volatile phenols. The contents of terpenes, esters, lactones, ketones, volatile acids, and volatile phenols showed general upward trends and reached amximum at half yellow or full ripe stages, meanwhile most alcohols, aldehydes, S- and N-containing compounds showed downward trends with fruit ripening. The putative aroma biosynthesis genes were quantified by RT- qPCR, and the correlation analysis suggested that CpLIS1 and CpP450-2 could be responsible for linalool and linalool oxide biosynthesis, respectively; BITC biosynthesis could be regulated at post-transcriptional, post-translational or enzymatic levels, CpAAT1 and CpACX1 could catalyze the formation of some specific esters or lactones. This study offered important clues for further dissection of the molecular mechanisms underlining aroma synthesis in 'Hong fei' during fruit ripening. [ABSTRACT FROM AUTHOR]

Tea (Camellia sinensis) is enriched with bioactive secondary metabolites, and is one of the most popular nonalcoholic beverages globally. Two tea reference genomes have been reported; however, the functional analysis of tea genes has lagged, mainly due to tea's recalcitrance to genetic transformation and the absence of alternative high throughput heterologous expression systems. A full-length cDNA collection with a streamlined cloning system is needed in this economically important woody crop species. RNAs were isolated from nine different vegetative tea tissues, pooled, then used to construct a normalized full-length cDNA library. The titer of unamplified and amplified cDNA library was 6.89 × 106 and 1.8 × 1010 cfu/mL, respectively; the library recombinant rate was 87.2%. Preliminary characterization demonstrated that this collection can complement existing tea reference genomes and facilitate rare gene discovery. In addition, to streamline tea cDNA cloning and functional analysis, a binary vector (pBIG2113SF) was reengineered, seven tea cDNAs isolated from this library were successfully cloned into this vector, then transformed into Arabidopsis. One FL-cDNA, which encodes a putative P1B-type ATPase 5 (CsHMA5), was characterized further as a proof of concept. We demonstrated that overexpression of CsHMA5 in Arabidopsis resulted in copper hyposensitivity. Thus, our data demonstrated that this represents an efficient system for rare gene discovery and functional characterization of tea genes. The integration of a tea FL-cDNA collection with efficient cloning and a heterologous expression system would facilitate functional annotation and characterization of tea genes. [ABSTRACT FROM AUTHOR]

The goal of the present study was to compare the structural and compositional differences of cuticle between tender leaf and fully-expanded leaf in Camellia sinensis, and provide metabolic base for the further characterization of wax biosynthesis in this economically important crop species. The tender second leaf and the fully-expanded fifth leaf from new twig were demonstrated to represent two different developmental stages, their cuticle thickness were measured by transmission electron microscopy. The thickness of the adaxial cuticle on the second and fifth leaf was 1.15 µm and 2.48 µm, respectively; the thickness of the abaxial cuticle on the second and fifth leaf was 0.47 µm and 1.05 µm, respectively. The thickness of the epicuticular wax layer from different leaf position or different sides of same leaf were similar. However, the intracuticular wax layer of the fifth leaf was much thicker than that of the second leaf. Total wax lipids were isolated from the second leaf and the fifth leaf, respectively. Gas chromatography-mass spectrometry analysis identified 51 wax constituents belonging to 13 chemical classes, including esters, glycols, terpenoids, fatty acids and their derivatives. Wax coverage on the second and fifth leaf was 4.76 µg/cm2 and 15.38 µg/cm2, respectively. Primary alcohols dominated in the tender second leaf. However, triterpenoids were the major components from the fully-expanded fifth leaf. The predominant carbon chains varied depending on chemical class. These data showed that the wax profiles of Camellia sinensis leaves are development stage dependent, suggesting distinct developmental dependent metabolic pathways and regulatory mechanisms. [ABSTRACT FROM AUTHOR]

• The lipid composition from papaya leave plasma membrane was characterized in detail. • Papaya plasma membrane lipidome remodeling by cold was revealed. • The fatty acid desaturases responsible for plasma membrane remodeling were identified. • This study uncovered several potential targets for cold tolerance improvement of papaya. Carica papaya is a cold-sensitive horticultural crop, the mechanisms underlying its cold sensitivity remains unclear which limit its genetic improvements in cold tolerance. In this study, aqueous dextran-polyethylene glycol two-phase partition systems were applied to purify plasma membrane from papaya leaves grown under 28 °C and 10 °C, the plasma membrane total lipids were analyzed by lipidomic approach; meanwhile, the transcription levels of putative fatty acid desaturases were quantified by RT-qPCR. We found that cerebrosides are dominate plasma membrane lipid species, followed by phospholipids and free sterols. Cold treatment increased the mono-unsaturated and di-unsaturated phospholipids, and decreased di-saturated phospholipids, the proportion of total phospholipids was not affected. Cold stress enhanced the transcription of CpFAD4 , CpFAD6 and CpFAB2−2. Pathway analysis suggested that the cold induction of CpFAB2−2 transcription and CpFAD2 enzyme activities play important roles for plasma membrane lipidome remodeling under cold stress. Our findings uncovered potential targets to improve papaya cold tolerance. [ABSTRACT FROM AUTHOR]

Fusarium wilt of banana (FWB), caused by Fusarium oxysporum f. sp. cubense (Foc), especially tropical race 4 (TR4), presents the foremost menace to the global banana production. Extensive efforts have been made to search for efficient biological control agents for disease management. Our previous study showed that Streptomyces sp. XY006 exhibited a strong inhibitory activity against several phytopathogenic fungi, including F. oxysporum . Here, the corresponding antifungal metabolites were purified and determined to be two cyclic lipopeptide homologs, lipopeptin A and lipopeptin B. Combined treatment with lipopeptin complex antagonized Foc TR4 by inhibiting mycelial growth and conidial sporulation, suppressing the synthesis of ergosterol and fatty acids and lowering the production of fusaric acid. Electron microscopy observation showed that lipopeptide treatment induced a severe disruption of the plasma membrane, leading to cell leakage. Lipopeptin A displayed a more pronounced antifungal activity against Foc TR4 than lipopeptin B. In pot experiments, strain XY006 successfully colonized banana plantlets and suppressed the incidence of FWB, with a biocontrol efficacy of up to 87.7%. Additionally, XY006 fermentation culture application improved plant growth parameters and induced peroxidase activity in treated plantlets, suggesting a possible role in induced resistance. Our findings highlight the potential of strain XY006 as a biological agent for FWB, and further research is needed to enhance its efficacy and mode of action in planta ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wang, Du, Chen, Guo, Mao, Wu, Wu, Han, Xie, Zeng, Shan, Wang and Yu.)