Growth Of Tea Plants Research Articles

Revealing the Inhibition of Tea Cultivar ‘Ziyan’ Root Growth Caused by High Nitrogen Based on Physiological, Metabolite, and Transcriptome Analyses

Nitrogen (N) is a key regulator in the growth of tea plants and the synthesis of amino acids (AAs) and related secondary metabolites, thus affecting the yield and quality of tea leaves. Increased N fertilization significantly improves the yield and quality of tea plants, but applying excess nitrogen wastes resources and causes pollution problems. Herein, we employed morphological, physiological, metabolomic, and RNA-seq methods to study the response of ‘Ziyan’ roots to high N. High N supply induced an increase in arginine (Arg), asparagine (Asn), and glutamine (Gln) in roots and simultaneously decreased sucrose, polyphenols, and caffeine contents. High N reduced the length, volume, number, and activity of the roots by 10.63%, 25.00%, 26.95%, and 14.50%, respectively, which inhibited ‘Ziyan’ root growth, probably by disturbing the regulation of carbon and nitrogen metabolism in the tea plant. According to the Kyoto Encyclopedia of Genes and Genome (KEGG) enrichment analysis, AAs, flavonoids, and flavonol-related pathways were relatively active after supplying high N. In addition, the transcriptome analysis identified NRT1/PTR and GOGAT as key genes, and the transcription factors (e.g., AP2/ERF, MYB, and WRKY) and auxins were actively involved in the high N stress response of ‘Ziyan’ roots. These findings will help us understand the adaptive mechanism of high N supply in tea tree roots and provide a reference for guiding the fertilization of ‘Ziyan’ tea plants.

Physical Land Suitability Assessment for Tea Cultivation Using GIS-Based Multi-Criteria Approach at Dabus Basin of Oromia Region, Southwest Ethiopia

Tea is economically important export commodity for Ethiopia Predicting the physical land suitability of tea is vital to avoid a sightless expansion of tea plantations and significant to recognize the potential suitable area for tea to disseminate of tea plantations in the country. Land suitability analysis is pre-request for assigning specific land for specific purposes. The study incorporate applications of Geographic Information System, Remote Sensing and Analytical Hierarchical Process (AHP) to allocate suitability weights to criteria that influence tea plant's growth to produce a predictive suitability map for its cultivation. Topography, Soils, climatic and land use features were included in the process as an important contributing factor for tea plant's growth. Each of the evaluations criteria layers were classified into four suitability class of not suitable, less suitable, suitable, and highly suitable. The results indicated that important influential factors affecting tea cultivation suitability evaluation were Rainfall (23.9%) followed by soils pH (18.05%) Elevation (12.72%), land use (10.79%), Aspect (9.07%), soils texture (6.96%), Slope (6.43), soils Depth (5.25%) temperature (3.42%) and drainage class (3.42%) respectively with 8.23% consistency index. The results revealed that the moderately suitable suitability class occupied the largest proportion of Land (84.92%), followed by highly suitable area (11.42%) and the unsuitable area (3.66%). the study area were precipitation, soil reaction, Altitude, Aspect and current Land use were identified as main limiting factors for Tea productions.

Biochar application method influences root growth of tea (Camellia sinensis L.) by altering soil biochemical properties

Although the application of biochar increases crop productivity and soil fertility, the effects of different biochar application methods on tea plant growth and soil nutrient status remain unclear. In this study, we conducted a root chamber experiment to assess the effects of various biochar application methods on root growth in tea plants and edaphic factors. Four treatments were included: T1) No biochar, T2) Homogenized biochar, T3) Localized biochar, and T4) Strip biochar. Biochar application generally resulted in higher macronutrient contents in tea plants, with 114–371%, 196–1167%, and 327–960% increases in nitrogen (N), phosphorus (P), and potassium (K), respectively. Biochar application also increased the soil pH by 18.7–22.5% compared to the control. T2 treatment increased the leaf and root biomasses by 80.9% and 262.2%, respectively, compared to the control, and the total carbon and soil nutrient [i.e., total N, inorganic N, available P, and available K, calcium (Ca), and magnesium (Mg)] contents were significantly higher than in the control. Variation in root growth was significantly explained by soil properties, including microbial biomass carbon, Ca, Mg, and total N (P < 0.05), with contributions of 47.9%, 15.6%, 17.6%, and 4.7%, respectively. These results suggest that biochar application in acidic soils would increase tea plant productivity and soil nutrient contents. Overall, homogenized biochar application led to optimal tea plant growth and soil fertility.

Magnesium promotes tea plant growth via enhanced glutamine synthetase-mediated nitrogen assimilation.

Acidic tea (Camellia sinensis) plantation soil usually suffers from magnesium (Mg) deficiency, and as such, application of fertilizer containing Mg can substantially increase tea quality by enhancing the accumulation of nitrogen (N)-containing chemicals such as amino acids in young tea shoots. However, the molecular mechanisms underlying the promoting effects of Mg on N assimilation in tea plants remain unclear. Here, both hydroponic and field experiments were conducted to analyze N, Mg, metabolite contents, and gene expression patterns in tea plants. We found that N and amino acids accumulated in tea plant roots under Mg deficiency, while metabolism of N was enhanced by Mg supplementation, especially under a low N fertilizer regime. 15N tracing experiments demonstrated that assimilation of N was induced in tea roots following Mg application. Furthermore, weighted gene correlation network analysis (WGCNA) analysis of RNA-seq data suggested that genes encoding glutamine synthetase isozymes (CsGSs), key enzymes regulating N assimilation, were markedly regulated by Mg treatment. Overexpression of CsGS1.1 in Arabidopsis (Arabidopsis thaliana) resulted in a more tolerant phenotype under Mg deficiency and increased N assimilation. These results validate our suggestion that Mg transcriptionally regulates CsGS1.1 during the enhanced assimilation of N in tea plant. Moreover, results of a field experiment demonstrated that high Mg and low N had positive effects on tea quality. This study deepens our understanding of the molecular mechanisms underlying the interactive effects of Mg and N in tea plants while also providing both genetic and agronomic tools for future improvement of tea production.

Studying the adaptability of promising breeding forms of tea to static environmental factors

The article presents the results of a long-term assessment of the adaptive potential of breeding forms of tea plants cultivated in the natural and climatic conditions of the North-Western Caucasus (the Republic of Adygea) in order to select the most promising samples from the existing gene pool and use them to breed local highly adaptive varieties. In the course of studying adaptability, generally accepted methods have been used, including the «Program and Methodology for the Study of Fruit, Berry and Nut Crops», 1999 and «Determining the Resistance of Fruit and Berry Crops to Cold Season Stressors in Field and Controlled Conditions», 2002. Meteorological and climatic features of the tea growing area have been analyzed, weather conditions compared with the biorhythms of introduced plants, their influence on the state and productivity of tea noted. Correlation relationships between the temperature factor and the onset of the development phase of tea plants have been characterized. As a result, data have been obtained on the winter hardiness of the studied forms for various components, resistance to excess and lack of heat, and the characteristics of the growth and development of tea plants in various weather conditions and against the background of various regeneration processes have been analyzed. To accelerate the determination of the viability of the conducting system, the authors carried out the growth of damaged shoots at room temperature and presented in the article the results of observations that made it possible to see hidden local tissue damage and characterize their types. The most adaptive forms are AF-3 and AF-5, which show the best resistance to damaging environmental factors, have a high regenerative capacity and can provide a good harvest of green tea leaves for the sustainable development of tea growing in Adygea.

Effects of Tea Plant Varieties with High- and Low-Nutrient Efficiency on Nutrients in Degraded Soil.

Tea plants are widely planted in tropical and subtropical regions globally, especially in southern China. The high leaching and strong soil acidity in these areas, in addition to human factors (e.g., tea picking and inappropriate fertilization methods) aggravate the lack of nutrients in tea garden soil. Therefore, improving degraded tea-growing soil is urgently required. Although the influence of biological factors (e.g., tea plant variety) on soil nutrients has been explored in the existing literature, there are few studies on the inhibition of soil nutrient degradation using different tea plant varieties. In this study, two tea plant varieties with different nutrient efficiencies (high-nutrient-efficiency variety: Longjing43 (LJ43); low-nutrient-efficiency variety: Liyou002 (LY002)) were studied. Under a one-side fertilization mode of two rows and two plants, the tea plant growth status, soil pH, and available nutrients in the soil profiles were analyzed, aiming to reveal the improvement of degraded soil using different tea varieties. The results showed that (1) differences in the phenotypic features of growth (such as dry tea yield, chlorophyll, leaf nitrogen (N), phosphorus (P), and potassium (K) content) between the fertilization belts in LJ43 (LJ43-near and LJ43-far) were lower than those in LY002. (2) RDA results showed that the crucial soil nutrient factors which determine the features of tea plants included available P, slowly available K, and available K. Moreover, acidification was more serious near the fertilization belt. The pH of the soil near LJ43 was higher than that near LY002, indicating an improvement in soil acidification. (3) Soil nutrient heterogeneity between fertilization belts in LJ43 (LJ43-near and LJ43-far) was lower than in LY002. In conclusion, the long-term one-side fertilization mode of two rows and two plants usually causes spatial heterogeneities in soil nutrients and aggravates soil acidification. However, LJ43 can reduce the nutrient heterogeneities and soil acidification, which is probably due to the preferential development of secondary roots. These results are helpful in understanding the influence of tea plant variety on improving soil nutrients and provide a relevant scientific reference for breeding high-quality tea varieties, improving the state of degraded soil and maintaining soil health.

STABILITY ANALYSIS OF DYNAMICAL MODEL INTERACTIONS TEA PLANTS, PESTS, AND DISEASES WITH FUNGICIDES AND INSECTICIDES CONTROLS

Tea plants are one of the exports commodities in Indonesia. In their development, the plantation ecosystem is heavily influenced by several factors, both internal and external factors. In the field of applied mathematics, mathematical modelling can be used to analyze the development of tea plant growth and their interactions each other in their ecosystem. The mathematical model in this research is combining three main models, there are logistic model, epidemiological model, and predator prey model by adding fungicide and insecticide controls. Furthermore, local and global stability analysis is carried out and the optimal control problem is solved by Pontryagin maximum principle. The results of the analysis obtained five equilibrium points. Local stability analysis was carried out using the Routh Hurwitz criteria which showed the fifth equilibrium point is locally asymptotically stable. The basic reproduction number in the model is 0.99. Because 16R0&lt;1" style="width: 28pt; height: 11pt;"&gt;, it can be concluded that there is no spread of disease in the tea plantation ecosystem after a period of 5 years. The control provided can reduce pest and disease attacks. After being given control, the population of infected tea plants decreased by 93.21%, Empoasca pests decreased by 99.47%, and leaf roller caterpillars decreased by 99.31% compared to the model that was not given control.

Transcriptome Analysis of 5-Aminolevulinic Acid Contributing to Cold Tolerance in Tea Leaves (Camellia sinensis L.)

Tea (Camellia sinensis L.) is an important perennial cash crop and a typical subtropical plant. It is widely concerned because of its unique flavor and health benefits. In recent years, low temperatures have severely restricted the growth of tea plants and quality of tea products, especially in spring. As a common precursor for all porphyrin compounds, 5-aminolevulinic acid (ALA) is involved in photosynthesis and respiration and plays an active role in improving salt, drought and low-temperature tolerance in plants. However, it is not yet clear what affect exogenous ALA has on tea plants’ tolerance under low temperature. In the present study, we collected and deciphered the transcriptome profiles from Shaancha No. 1 leaf tissues under low temperature (−4 °C) treatment (T-4), exogenous ALA application (T-A), pretreated ALA before low temperature (T-A-4) and untreated control (T-CK). Results showed that 4990 (2375 up- and 2615 down-regulated), 223 (103 up- and 120 down-regulated) and 92 (13 up- and 79 down-regulated) differentially expression genes (DEGs) were identified at T-CK vs. T-4, T-CK vs. T-A and T-4 vs. T-A-4, respectively. Both T-4 and T-A treatments triggered a myriad of stress resistance genes up-regulated related to multiple signaling pathways by means of Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. This included MAPK, a toll-like receptor that signals pathways involved in cold resistance. However, gene ontology (GO) analysis showed that the DEGs in T-4 treatment were mainly enriched in the phenylpropanoid metabolic and redox processes that were relevant to membrane structure damage response. In contrast, the DEGs in T-A treatment were mainly enriched in cell recognition and amylase activity. Furthermore, in pairwise comparison of T-A-4 vs. T-4, the DEGs were enriched in ascorbate and aldarate, retionol, taurine and hypotaurine, glutathione metabolic pathways and two biosynthesis process including zeatin, diterpenoid biosynthesis, which might contribute to mitigating the damage caused by low temperature. Overall, these results indicated that exogenous ALA application may improve the biochemical attributes and enhance the tolerance to low temperature, which provides a valuable strategy to improve tea quality and cold stress.

Molecular and physiological mechanisms of tea (Camellia sinensis (L.) O. Kuntze) leaf and root in response to nitrogen deficiency

BackgroundAs an economically important crop, tea is strongly nitrogen (N)-dependent. However, the physiological and molecular mechanisms underlying the response of N deficiency in tea are not fully understood. Tea cultivar “Chunlv2” [Camellia sinensis (L.) O. Kuntze] were cultured with a nutrient solution with 0 mM [N-deficiency] or 3 mM (Control) NH4NO3 in 6 L pottery pots containing clean river sands.ResultsN deficiency significantly decreased N content, dry weight, chlorophyll (Chl) content, L-theanine and the activities of N metabolism-related enzymes, but increased the content of total flavonoids and polyphenols in tea leaves. N deficiency delayed the sprouting time of tea buds. By using the RNA-seq technique and subsequent bioinformatics analysis, 3050 up-regulated and 2688 down-regulated differentially expressed genes (DEGs) were isolated in tea leaves in response to N deficiency. However, only 1025 genes were up-regulated and 744 down-regulated in roots. Gene ontology (GO) term enrichment analysis showed that 205 DEGs in tea leaves were enriched in seven GO terms and 152 DEGs in tea roots were enriched in 11 GO items based on P < 0.05. In tea leaves, most GO-enriched DEGs were involved in chlorophyll a/b binding activities, photosynthetic performance, and transport activities. But most of the DEGs in tea roots were involved in the metabolism of carbohydrates and plant hormones with regard to the GO terms of biological processes. N deficiency significantly increased the expression level of phosphate transporter genes, which indicated that N deficiency might impair phosphorus metabolism in tea leaves. Furthermore, some DEGs, such as probable anion transporter 3 and high-affinity nitrate transporter 2.7, might be of great potential in improving the tolerance of N deficiency in tea plants and further study could work on this area in the future.ConclusionsOur results indicated N deficiency inhibited the growth of tea plant, which might be due to altered N metabolism and expression levels of DEGs involved in the photosynthetic performance, transport activity and oxidation–reduction processes.

Arbuscular mycorrhizal fungus alleviates anthracnose disease in tea seedlings.

Tea has been gaining increasing popularity all over the world in recent years, and its yield and quality depend on the growth and development of tea plants [Camellia sinensis (L.) Kuntze] in various environments. Nowadays, biotic stress and extreme weather, such as high temperature, drought, waterlogging, pests, and diseases, bring about much pressure on the production of tea with high quality. Wherein anthracnose, which is the most common and serious disease of tea plants, has earned more and more attention, as its control mainly relies on chemical pesticides. Arbuscular mycorrhizal fungi (AMF), forming symbiosis with most terrestrial plants, participate in plant resistance against the anthracnose disease, which was found by previous studies in a few herbaceous plants. However, there are a few studies about arbuscular mycorrhizal (AM) fungal regulation of the resistance to the anthracnose pathogen in woody plants so far. In this paper, we investigated the effect of AMF on the development of anthracnose caused by Colletotrichum camelliae and tried to decipher the pertinent mechanism through transcriptome analysis. Results showed that inoculating AMF significantly reduced the damage of anthracnose on tea seedlings by reducing the lesion area by 35.29% compared to that of the control. The content of superoxide anion and activities of catalase and peroxidase significantly increased (P < 0.05) in mycorrhizal treatment in response to the pathogen with 1.23, 2.00, and 1.39 times higher, respectively, than those in the control. Pathways of plant hormone signal transduction, mitogen-activated protein kinase (MAPK) signaling, and phenylpropanoid biosynthesis might play roles in this regulation according to the transcriptomic results. Further redundancy analysis (RDA) and partial least squares structural equation modeling (PLS-SEM) analysis found that plant hormones, such as auxin and ethylene, and the antioxidant system (especially peroxidase) were of great importance in the AM fungal alleviation of anthracnose. Our results preliminarily indicated the mechanisms of enhanced resistance in mycorrhizal tea seedlings to the anthracnose pathogen and provided a theoretical foundation for the application of AMF as one of the biological control methods in tea plantations.

Glycine-Induced Phosphorylation Plays a Pivotal Role in Energy Metabolism in Roots and Amino Acid Metabolism in Leaves of Tea Plant.

Phosphorylation is the most extensive post-translational modification of proteins and thus regulates plant growth. However, the regulatory mechanism of phosphorylation modification on the growth of tea plants caused by organic nitrogen is still unclear. In order to explore the phosphorylation modification mechanism of tea plants in response to organic nitrogen, we used glycine as the only nitrogen source and determined and analyzed the phosphorylated proteins in tea plants by phosphoproteomic analysis. The results showed that the phosphorylation modification induced by glycine-supply played important roles in the regulation of energy metabolism in tea roots and amino acid metabolism in tea leaves. In roots, glycine-supply induced dephosphorylation of proteins, such as fructose-bisphosphate aldolase cytoplasmic isozyme, glyceraldehyde-3-phosphate dehydrogenase, and phosphoenolpyruvate carboxylase, resulted in increased intensity of glycolysis and decreased intensity of tricarboxylic acid cycle. In leaves, the glycine-supply changed the phosphorylation levels of glycine dehydrogenase, aminomethyltransferase, glutamine synthetase, and ferredoxin-dependent glutamate synthase, which accelerated the decomposition of glycine and enhanced the ability of ammonia assimilation. In addition, glycine-supply could improve the tea quality by increasing the intensity of amino acids, such as theanine and alanine. This research clarified the important regulatory mechanism of amino acid nitrogen on tea plant growth and development through protein phosphorylation.

Evaluating drought stress tolerance in different Camellia sinensis L. cultivars and effect of melatonin on strengthening antioxidant system

• In this study, the tolerance of different cultivars to drought stress have been determined. • We can suggest cultivar DG 39 and DN as tolerant cultivars to drought stress, and this cultivar can be used in breeding programs (hybridization). • Exogenously applied melatonin improve the ability of tea seedlings to tolerate drought stress. Drought stress really restring the growth and development of tea plant and affecting quality and yield. In tea growing areas of Iran, drought stress is a serious problem that affects the yield and quality of green leaves, therefore introducing cultivars that tolerate drought stress is one of the breeding purpose. To distinguish the variations in four tea cultivars response to drought stress and the role of melatonin in reducing the destructive effects of drought stress, an experiment was done at Tea Research Center of Iran, using the factorial based on completely randomized design with three replicates. The first experimental factor was the cultivar at 4 levels (DG39, DG7, DN and Kashef) and the second factor was irrigation interruption treatment at 5 levels, including control (full irrigation), irrigation interruption for 7 days with 100 µm melatonin foliar application, irrigation interruption for 7 days without melatonin foliar application, irrigation interruption for 14 days with melatonin foliar application and irrigation interruption for 14 days without melatonin foliar application. The study indicated that the physiological and biochemical traits were significantly different among the cultivars and treatments. Based on some traits such as malondialdehyde, the activities of antioxidant enzymes (CAT, POD), carotenoid and polyphenol content, DG 39 and based on traits such as proline, total sugar and chlorophyll content, DN are introduced as the cultivars that showed better tolerance to drought stress and these cultivars can be used in future breeding programs. Also melatonin treatment significantly enhanced the drought tolerance of tea seedlings, as demonstrated by decreased membrane damage, raised the concentration of proline, total protein, and total sugar and enhanced the activities of catalase and peroxidase during drought stress.

Influence of chicken feather waste derived protein hydrolysate on the growth of tea plants under different application methods and fertilizer rates.

Modern agriculture prioritizes eco-friendly and sustainable strategies to enhance crop growth and productivity. The utilization of protein hydrolysate extracted from chicken feather waste as a plant biostimulant paves the path to waste recycling. A greenhouse experiment was performed to evaluate the implications of different doses (0, 1, 2, and 3g L-1) of chicken feather protein hydrolysate (CFPH), application method (soil and foliar), and fertilizer rate (50% and 100%) on the growth performance of tea nursery plants. The highest dose of CFPH (3g L-1) increased the shoot and root dry weights by 43% and 70%, respectively over control. However, no significant differences were observed between 2 and 3g L-1 doses in plant dry weight, biometric, and root morphological parameters. Foliar application of CFPH significantly increased all the growth parameters compared to soil drenching except N, P, and K concentrations in leaves and roots. Plants grown under 100% fertilizer rate showed better growth performance than 50% fertilizer rate. Tea nursery plants treated with foliar 2g L-1 dose and grown under full fertilizer rate recorded the highest plant dry weight, root length, and root surface area. However, tea plants under 50% fertilizer rate and treated with foliar 2 and 3g L-1 doses sustained the growth similar to untreated plants under 100% fertilizer rate. The significantly higher N, P, and K concentrations in leaves were observed in plants treated with soil drenching of 2 and 3g L-1 CFPH doses under 100% fertilizer rate. Our results indicate that the application of CFPH as a foliar spray is highly effective in producing vigorous tea nursery plants suitable for field planting, eventually capable of withstanding stress and higher yield.

Genome-wide identification and characterization of PIN-FORMED (PIN) and PIN-LIKES (PILS) gene family reveals their role in adventitious root development in tea nodal cutting (Camellia Sinensis)

Auxin affects all aspects of plant growth and development, including morphogenesis and adaptive responses. Auxin transmembrane transport is promoted by PIN formation (PIN) and a structurally similar PIN-like (PILS) gene family, which jointly controls the directional transport of the auxin between plant cells, and the accumulation of intracellular auxin. At present, there is no study investigating the roles of CslPIN and CslPILS gene family in root development in the tea plant (Camellia sinensis). In this study, 8 CslPIN and 10 CslPILS genes were identified in the tea plant, and their evolutionary relationships, physical and chemical properties, conserved motifs, cis-acting elements, chromosome location, collinearity, and expression characteristics were analyzed. The mechanism of CslPIN and CslPILS in the formation of tea adventitious roots (ARs) was studied by the AR induction system. Through functional verification, the regulation of CslPIN3 gene on root growth and development of tea plant was studied by over-expression of CslPIN3 in Arabidopsis thaliana and in situ hybridization in Camellia sinensis. The results confirmed CslPIN3 was involved in the regulation of root growth and development as well as auxin accumulation. This study provides a better insight into the regulatory mechanism of CslPIN and CslPILS gene family on the formation of AR in tea plant.

Genome-Wide Identification of AMT2-Type Ammonium Transporters Reveal That CsAMT2.2 and CsAMT2.3 Potentially Regulate NH4+ Absorption among Three Different Cultivars of Camellia sinensis

Ammonium (NH4+), as a major inorganic source of nitrogen (N) for tea plant growth, is transported and distributed across membranes by the proteins of ammonium transporters (AMTs). However, the AMT2-type AMTs from tea plants remain poorly understood. In this study, five CsAMT2 subfamily genes were identified in tea plant genomes, and their full-length coding sequences (CDS) were isolated from roots. Then, a NH4+ uptake kinetic comparison of Fudingdabaicha (FD), Huangdan (HD), and Maoxie (MX) showed that FD was a high N efficiency (HNE) cultivar that had a wide range of adaptability to NH4+, HD was a high N efficiency under high N conditions (HNEH) cultivar, in which it was easy to obtain higher yield in a high N environment, and MX was a high N efficiency under low N conditions (HNEL) cultivar, which had a higher affinity for NH4+ than the other two. Tissue-specific expression analysis suggested that CsAMT2.2 and CsAMT2.3 were highly expressed in the roots, indicating that these two members may be unique in the CsAMT2 subfamily. This is further supported by our findings from the temporal expression profiles in the roots among these three different N adaptation cultivars. Expression levels of CsAMT2.2 and CsAMT2.3 in FD and HD were upregulated by a short time (2 h) under high NH4+ treatment, while under low NH4+ treatment, CsAMT2.2 and CsAMT2.3 were highly expressed at 0 h and 2 h in the HNEL-type cultivar-MX. Furthermore, the functional analysis illustrated that CsAMT2.2 and CsAMT2.3 could make a functional complementation of NH4+-defective mutant yeast cells at low NH4+ levels, and the transport efficiency of CsAMT2.3 was higher than that of CsAMT2.2. Thus, we concluded that CsAMT2.2 and CsAMT2.3 might play roles in controlling the NH4+ uptake from the soil to the roots. These results will further the understanding of the NH4+ signal networks of AMT2-type proteins in tea plants.

Two or more bacterial mixtures increase tea plant growth, yield, nutrient intake and antioxidant enzyme activity

This study was carried out in order to determine bacterial strains that can be used as biological fertilizer in tea cultivation. The present study assessed possible effects of mineral NPK fertilizer (TF: 80 kg ha−1 compound 25: 5:10) and ACC deaminase-containing, N2-fixing, and P-solubilizing 6 bacteria strains as single (T1-T6:Pseudomonas fluorescens RC483, Pseudomonas fluorescens RC77E, Pseudomonas putida RC19b, Bacillus licheniformis RC5B2, Bacillus subtilis RC5A2, Bacillus pumilus RC7A1), binary (T7: RC483 + RC5A2, T8: RC77E + RC7A1), triple (T9: RC77E + RC5A2+ RC5B2, T10: RC483+ RC19b + RC7A1) and quadruple (T11: RC77E + RC5B2 + RC7A1+ RC5A2) inoculations, chemical fertilizer (80 kg ha−1 compound 25: 5: 10) and control treatments on growth, yield, yield, nutrient uptake and enzyme activity of Pazar-20 tea clones manufactured for commercial purposes. Experimental groups determined in the present study were formed by considering the results of our preliminary study and bacteria that do not have antagonistic effects on each other. Results showed that dual, triple and quadruple inoculations stimulated overal second and third leaf area, leaf yield, macro- and micro-nutrient concenrations, chlorophyll and anthocyanin content, and antioxidant, oxidative, catalytic, hydrolytic and quality-related enzymes activity. Tea plant growth responses were dependent on the inoculant strain and formulations used, as well as on the parameters evaluated. In conclusion, bacterial seed inoculations especially with quadruple bacterial formulation determined to be most effective in tea growth can improve tea yield and productivity on sustainable basis. The ability to increase enzyme activity, which may be important in taste and aroma, leaf antioxidant, oxidative pentose phosphate pathway (OPPP) and tea processing technology by using different combinations prepared with bacterial isolates will be able to a significant contribution to tea technology studies.

Insights into the functional role of tea microbes on tea growth, quality and resistance against pests and diseases

Tea is an economical and most widely used beverage across the globe owing to its unique fragrance and flavor. Plant microbe interaction has emerged as an important topic which got the attention of scientists to improve plant performance. Tea microbes remained a prominent research topic for scientists over the years as tea microbes helps in nutrient cycling and stress management which in turn improve the tea growth, yield and quality. The roots of tea plants are colonized by various microbes including arbuscular mycorrhizal fungi (AMF), bacterial communities, and endophytes increase root growth, development and nutrient uptake which in turn improve tea growth, yield and quality. These microbes also increase the concentration of nutrients, amino acids, soluble proteins, flavonoids, catechuic acid, glucose, fructose, sucrose contents caffeine, and polyphenols concentration in tea plants. Besides this, these microbes also protect the tea plants from harmful pest and diseases which in turn leads to an appreciable improvement in plant growth and development. The most important goal of any farming system is to establish a system with production of maximum food while minimizing impacts on the environment. The present review article highlights the role of various microbes in improving the growth, yield and quality of tea plants. In addition, we also discussed the research gaps to improve our understanding about the role of tea microbes in improving tea growth, yield, pest and diseases resistance. We believe that this review will provide a better insight into the existing knowledge of tea microbes in improving tea growth and yield.

Effects of a weak supply of light at night on the growth and quality components of tea plants

Abstract Supplying artificial light is widely used in crop cultivation to improve yield and quality. In this study, we investigated the effects of a weak supply of light (WSL) on the growth and quality components of tea plants. Starting from mid-winter (20 January 2021), the purple tea (Camellia sinensis) cultivar ‘Ziyan’ was exposed to four different spectra at an intensity of 2 μmol · m−2 · s−1 or 5 μmol · m−2 · s−1 for 3 h or 5 h after sunset. The field observations showed that the sprouting index, which represents the time and speed of bud flush, was significantly higher in most of the WSL treatments than in the control (CK, p &lt; 0.01). The total content of catechin in the harvested leaves of 3 WSL treatments was 11.51%–18.94% higher than that of the CK, but the content of anthocyanin of 4 WSL treatments unexpectedly decreased by 6.77%–11.69% (p &lt; 0.05). The differences in yield, free amino acids and caffeine contents between the WSL treatments and CK were not significant. We concluded that the WSL treatments during the early spring night had positive impacts on the growth and some quality components of tea plants.

Development and Application of SNP-KASP Markers Based on Genes Related to Nitrogen Uptake, Assimilation and Allocation in Tea Plant (Camellia sinensis L.)

Nitrogen is essential for the growth and quality formation of tea plants. Excessive and inefficient use of nitrogen fertilizer leads to cost increases and ecosystem pollution. It is important to improve the nitrogen use efficiency (NUE) for tea plantation. Breeding high-NUE varieties by marker-assisted selection using NUE-associated genes is a viable approach. However, few molecular markers related to nitrogen uptake and utilization have been identified in tea plants. In this study, a total of 2554 SNP loci within NUE-related genes were identified in a database. Of the non-synonymous SNPs, 46 were successfully converted to KASP markers. These markers were deployed on 35 tea germplasms to assess their suitability and accuracy in genetic analysis. The results show that 42 markers exhibited polymorphisms and the PIC values ranged from 0.05 to 0.38. The clustering results of the phylogenetic tree was basically consistent with the phenotype, showing that tea germplasms with high nitrogen accumulation and large biomass were grouped into one cluster. Using these markers, the fingerprints of these germplasms were constructed. The preliminary association analysis showed that there were two SNPs (CsSNP07 and CsSNP11) within CsNRT2.4 (CSS0001304) that were significantly associated with nitrogen accumulation (F = 4.631, P = 0.039 and F = 3.054, p = 0.047) and one SNP (CsSNP40) within CsAAP6 (CSS0035405) that was significantly associated with biomass (F = 3.842, p = 0.032). These functional SNP-KASP markers will be valuable for the early evaluation of tea germplasms and could accelerate the breeding of high-NUE varieties.

Exogenous Melatonin Attenuates Cd Toxicity in Tea (Camellia sinensis)

Cadmium (Cd) is highly toxic and not easily degradable. It damages plant growth and results in large-scale economic losses. The present study explored the feasibility of using melatonin to alleviate Cd toxicity, and to reduce Cd accumulation in tea seedlings cultivated in Cd-contaminated soil. Exogenous melatonin, especially at 150 μM, promoted tea seedling growth under Cd stress, and increased the photosynthetic pigment by 16% and soluble protein content by 5%. Furthermore, melatonin effectively increased the activities of superoxide dismutase (SOD), and peroxidase (POD) by 21 and 31%, respectively, contributed to a decrease of the malondialdehyde (MDA) by 2% and the Cd content in leaves by 52%. Furthermore, soil enzyme activities were enhanced, including acid phosphatase (ACP), urease (UE), soil sucrase (SC), and soil catalase (CAT), by 11, 70, 1, and 18%, respectively, along with a pH reduction and available Cd content increase, after melatonin application. Taken together, our results provide evidence that melatonin lessens the adverse Cd effects on tea seedlings’ physiology, mainly through enhancing the antioxidant capacity of the plants and soils to scavenge reactive oxygen species (ROS) upon Cd exposure. Therefore, melatonin may be used as a modulator to alleviate Cd-induced toxicity in tea seedlings, thereby resulting in healthier tea plant growth.