Physiological, Transcriptomic Investigation on the Tea Plant Growth and Yield Motivation by Chitosan Oligosaccharides

Chitosan oligosaccharides (COS) has been abundantly studied for its application on regulating plant growth of many horticultural and agricultural crops. We presented here the effect of COS on tea plant growth and yield by physiological and transcriptomic checking. The results showed that COS treatment can enhance the antioxidant activity of superoxide dismutase (SOD) and peroxidase (POD) and increase the content of chlorophyll and soluble sugar in tea plants. The field trail results show that COS treatment can increase tea buds’ density by 13.81–23.16%, the weight of 100 buds by 15.94–18.15%, and the yield by 14.22–21.08%. Transcriptome analysis found 5409 COS-responsive differentially expressed genes (DEGs), including 3149 up-regulated and 2260 down-regulated genes, and concluded the possible metabolism pathway that responsible for COS promoting tea plant growth. Our results provided fundamental information for better understanding the molecular mechanisms for COS’s acting on tea plant growth and yield promotion and offer academic support for its practical application in tea plant.

The relationship Between Soil Chemical Properties and Uptake of Tea Plant Nutrient in PTPN VI Jambi

Healthy soil could support plant growth by optimizing the availability of nutrients. The availability of nutrients influences the health of tea plants. Nutrient deficiencies would affect the plant physiology that exhibits the plant withering. This study aimed to define the relationship between soil nutrient availability with plant nutrient uptake. This research was conducted by managing secondary data soil chemical properties, and tea plant nutrients analyzed statistically with Pearson correlation. This study only found a significant correlation between soil pH with P and Mg uptake. Correlation results between soil nutrient and plant nutrient uptake obtained a significantly negative correlation on soil pH with P and Mg nutrients with a correlation value of pH-P (r=-0.52), pH-Mg (r=-0.52). There was no correlation between other soil nutrients and plant nutrient uptake. The results of this study can be used to determine the dose of fertilization and the management recommendation of tea plants.

The NAC-like transcription factor CsNAC7 positively regulates the caffeine biosynthesis-related gene yhNMT1 in Camellia sinensis

Caffeine is an important functional substance and is abundant in tea plant, but little is known about how its biosynthesis is regulated by transcription factors. In this study, the NAC-like transcription factor-encoding gene CsNAC7, which is involved in caffeine synthesis, was isolated from a Yinghong 9 cDNA library using a yeast one-hybrid assay; this gene comprises 1371 bp nucleotides and is predicted to encode 456 amino acids. The expression of CsNAC7 at the transcriptional level in tea shoots shared a similar pattern with that of the caffeine synthase gene yhNMT1 in the spring and summer, and its expressed protein was localized in the nucleus. Assays of gene activity showed that CsNAC7 has self-activation activity in yeast, that the active region is at the N-terminus, and that the transient expression of CsNAC7 could significantly promote the expression of yhNMT1 in tobacco leaves. In addition, overexpression or silencing of CsNAC7 significantly increased or decreased the expression of yhNMT1 and the accumulation of caffeine in transgenic tea calli, respectively. Our data suggest that the isolated transcription factor CsNAC7 positively regulates the caffeine synthase gene yhNMT1 and promotes caffeine accumulation in tea plant.

The Relation Study of Soil Nutrient to Productivity of productive Tea Plants in Pagar Alam Tea Plantation, South Sumatra

Tea plantation area in recent years has decreased by 0.75% annually. With the decline in the area of tea plantations, productivity also decreases. Decreased productivity can be caused by erosion, climate, clones, and management applications. The purpose of this study was to determine the availability of soil nutrients in Pagar Alam tea plantation and the relationship with productivity. The observation was held with secondary data and analyzed statistically with the correlation method. Parameters observed were pH, organic C, total N, P2O5, exchangeable K, and exchangeable Mg. The result showed that the relationship between soil nutrients such as organic C, total N, available P, exchangeable K, and exchangeable Mg with productivity was weak with correlation coefficient values of 0.00 – 0.199. These results also showed that the correlation was negative, which means that the two variables were inversely proportional. Plant maintenance factors have a more significant role in tea plant productivity than nutrients and fertilization, such as picking, pruning, root zone improvement, and plant pest control. If these factors can be controlled properly, shoot production will increase, and plant health can be maintained. Thus, in this case, the nutrient factor is not the main factor affecting productivity at Pagar Alam Tea Plantation, indeed the plant care factor.

Assessment of tea plant (Camellia sinensis L.) accessions for pollen sources in natural crossing by using microsatellites

Tea (Camellia sinensis L. [O.] Kuntze) is a highly cross-pollinated and self-incompatible plant. Seeds can be harvested from specific individual mother plants in polyclonal tea gardens. Whether the pollen donor plays an important role in seed formation remains unclear. This study aimed to identify the male parents of 72 natural hybridized progenies (F1) from one female parent on the basis of a putative specific allele by using simple-sequence repeat (SSR) markers and the exclusion-likelihood method with Cervus 3.0 software. The genetic material, which comprised seven accessions of C. sinensis L., was acquired from Assamica planted in the Kayulandak polyclonal seed garden of the Pagilaran tea plantation in Batang District, Central Java, Indonesia, and was studied during 2019 and 2020. The genotype PGL-15 was used as the female parent, whereas the six candidate genotypes PGL-10, GMB-9, GMB-7, TPS-93, GMB-11, and TRI-2025 were used as the male parents. In this study, 13 SSR loci were used to identify the male parents of the F1 progenies obtained through natural hybridization between one female and six male tea accessions. Results indicated that the exclusion-likelihood method, which correctly predicted 100% of the male parents, was more effective than the putative specific allele approach, which correctly predicted only 34.72% of the male parents in the 72 hybridized F1 progenies of tea plants.

Dynamics of Fractional Model of Biological Pest Control in Tea Plants with Beddington–DeAngelis Functional Response

In this study, we depicted the spread of pests in tea plants and their control by biological enemies in the frame of a fractional-order model, and its dynamics are surveyed in terms of boundedness, uniqueness, and the existence of the solutions. To reduce the harm to the tea plant, a harvesting term is introduced into the equation that estimates the growth of tea leaves. We analyzed various points of equilibrium of the projected model and derived the conditions for the stability of these equilibrium points. The complex nature is examined by changing the values of various parameters and fractional derivatives. Numerical computations are conducted to strengthen the theoretical findings.

NHX Gene Family in Camellia sinensis: In-silico Genome-Wide Identification, Expression Profiles, and Regulatory Network Analysis

Salt stress affects the plant growth and productivity worldwide and NHX is one of those genes that are well known to improve salt tolerance in transgenic plants. It is well characterized in several plants, such as Arabidopsis thaliana and cotton; however, not much is known about NHXs in tea plant. In the present study, NHX genes of tea were obtained through a genome-wide search using A. thaliana as reference genome. Out of the 9 NHX genes in tea, 7 genes were localized in vacuole while the remaining 2 genes were localized in the endoplasmic reticulum (ER; CsNHX8) and plasma membrane (PM; CsNHX9), respectively. Furthermore, phylogenetic relationships along with structural analysis which includes gene structure, location, and protein-conserved motifs and domains were systematically examined and further, predictions were validated by the expression analysis. The dN/dS values show that the majority of tea NHX genes is subjected to strong purifying selection under the course of evolution. Also, functional interaction was carried out in Camellia sinensis based on the orthologous genes in A. thaliana. The expression profiles linked to various stress treatments revealed wide involvement of NHX genes from tea in response to various abiotic factors. This study provides the targets for further comprehensive identification, functional study, and also contributed for a better understanding of the NHX regulatory network in C. sinensis.