Essential oil-grafted copper nanoparticles as a potential next-generation fungicide for holistic disease management in maize.

Sustainable food production is necessary to meet the demand of the incessantly growing human population. Phytopathogens pose a major constraint in food production, and the use of conventional fungicides to manage them is under the purview of criticism due to their numerous setbacks. In the present study, essential oil-grafted copper nanoparticles (EGC) were generated, characterized, and evaluated against the maize fungal pathogens, viz., Bipolaris maydis, Rhizoctonia solani f. sp. sasakii, Macrophomina phaseolina, Fusarium verticillioides, and Sclerotium rolfsii. The ED50 for the fungi under study ranged from 43 to 56 µg ml-1, and a significant inhibition was observed at a low dose of 20 µg ml-1 under in vitro conditions. Under net house conditions, seed treatment + foliar spray at 250 and 500 mg L-1 of EGC performed remarkably against maydis leaf blight (MLB), with reduced percent disease index (PDI) by 27.116 and 25.292%, respectively, in two Kharif seasons (May-Sep, 2021, 2022). The activity of enzymatic antioxidants, viz., ß-1, 3-glucanase, PAL, POX, and PPO, and a non-enzymatic antioxidant (total phenolics) was increased in treated maize plants, indicating host defense was triggered. The optimum concentrations of EGC (250 mg L-1 and 500 mg L-1) exhibited improved physiological characteristics such as photosynthetic activity, shoot biomass, plant height, germination percentage, vigor index, and root system traits. However, higher concentrations of 1,000 mg L-1 rendered phytotoxicity, reducing growth, biomass, and copper bioaccumulation to high toxic levels, mainly in the foliar-sprayed maize leaves. In addition, EGC and copper nanoparticles (CuNPs) at 1,000 mg L-1 reduced the absorption and concentration of manganese and zinc indicating a negative correlation between Cu and Mn/Zn. Our study proposes that the CuNPs combined with EO (Clove oil) exhibit astounding synergistic efficacy against maize fungal pathogens and optimized concentrations can be used as an alternative to commercial fungicides without any serious impact on environmental health.

Genome-wide identification and development of miniature inverted-repeat transposable elements and intron length polymorphic markers in tea plant (Camellia sinensis).

Marker-assisted breeding and tagging of important quantitative trait loci for beneficial traits are two important strategies for the genetic improvement of plants. However, the scarcity of diverse and informative genetic markers covering the entire tea genome limits our ability to achieve such goals. In the present study, we used a comparative genomic approach to mine the tea genomes of Camellia sinensis var. assamica (CSA) and C. sinensis var. sinensis (CSS) to identify the markers to differentiate tea genotypes. In our study, 43 and 60 Camellia sinensis miniature inverted-repeat transposable element (CsMITE) families were identified in these two sequenced tea genomes, with 23,170 and 37,958 putative CsMITE sequences, respectively. In addition, we identified 4912 non-redundant, Camellia sinensis intron length polymorphic (CsILP) markers, 85.8% of which were shared by both the CSS and CSA genomes. To validate, a subset of randomly chosen 10 CsMITE markers and 15 CsILP markers were tested and found to be polymorphic among the 36 highly diverse tea genotypes. These genome-wide markers, which were identified for the first time in tea plants, will be a valuable resource for genetic diversity analysis as well as marker-assisted breeding of tea genotypes for quality improvement.

A first-generation haplotype map (HapMap-1) of tea (Camellia sinensis L. O. Kuntz).

MOTIVATION: Tea is a cross-pollinated woody perennial plant, which is why, application of conventional breeding is limited for its genetic improvement. However, lack of the genome-wide high-density SNP markers and genome-wide haplotype information has greatly hampered the utilization of tea genetic resources toward fast-track tea breeding programs. To address this challenge, we have generated a first-generation haplotype map of tea (Tea HapMap-1). Out-crossing and highly heterozygous nature of tea plants, make them more complicated for DNA-level variant discovery. RESULTS: In this study, whole genome re-sequencing data of 369 tea genotypes were used to generate 2,334,564 biallelic SNPs and 1,447,985 InDels. Around 2928.04 million paired-end reads were used with an average mapping depth of ∼0.31× per accession. Identified polymorphic sites in this study will be useful in mapping the genomic regions responsible for important traits of tea. These resources lay the foundation for future research to understand the genetic diversity within tea germplasm and utilize genes that determine tea quality. This will further facilitate the understanding of tea genome evolution and tea metabolite pathways thus, offers an effective germplasm utilization for breeding the tea varieties. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Genome-wide identification, evolutionary relationship and expression analysis of AGO, DCL and RDR family genes in tea.

Three gene families in plants viz. Argonaute (AGOs), Dicer-like (DCLs) and RNA dependent RNA polymerase (RDRs) constitute the core components of small RNA mediated gene silencing machinery. The present study endeavours to identify members of these gene families in tea and to investigate their expression patterns in different tissues and various stress regimes. Using genome-wide analysis, we have identified 18 AGOs, 5 DCLs and 9 RDRs in tea, and analyzed their phylogenetic relationship with orthologs of Arabidopsis thaliana. Gene expression analysis revealed constitutive expression of CsAGO1 in all the studied tissues and stress conditions, whereas CsAGO10c showed most variable expression among all the genes. CsAGO10c gene was found to be upregulated in tissues undergoing high meristematic activity such as buds and roots, as well as in Exobasidium vexans infected samples. CsRDR2 and two paralogs of CsAGO4, which are known to participate in biogenesis of hc-siRNAs, showed similarities in their expression levels in most of the tea plant tissues. This report provides first ever insight into the important gene families involved in biogenesis of small RNAs in tea. The comprehensive knowledge of these small RNA biogenesis purveyors can be utilized for tea crop improvement aimed at stress tolerance and quality enhancement.

Comparative analysis of chloroplast genomes indicated different origin for Indian tea (Camellia assamica cv TV1) as compared to Chinese tea.

Based upon the morphological characteristics, tea is classified botanically into 2 main types i.e. Assam and China, which are morphologically very distinct. Further, they are so easily pollinated among themselves, that a third category, Cambod type is also described. Although the general consensus of origin of tea is India, Burma and China adjoining area, yet specific origin of China and Assam type tea are not yet clear. Thus, we made an attempt to understand the origin of Indian tea through the comparative analysis of different chloroplast (cp) genomes under the Camellia genus by performing evolutionary study and comparing simple sequence repeats (SSRs) and codon usage distribution patterns among them. The Cp genome based phylogenetic analysis indicated that Indian Tea, TV1 formed a different group from that of China tea, indicating that TV1 might have undergone different domestications and hence owe different origins. The simple sequence repeats (SSRs) analysis and codon usage distribution patterns also supported the clustering order in the cp genome based phylogenetic tree.

TeaMiD: a comprehensive database of simple sequence repeat markers of tea.

Tea is a highly cross-pollinated, woody, perennial tree. High heterozygosity combined with a long gestational period makes conventional breeding a cumbersome process. Therefore, marker-assisted breeding is a better alternative approach when compared with conventional breeding. Considering the large genome size of tea (~3 Gb), information about simple sequence repeat (SSR) is scanty. Thus, we have taken advantage of the recently published tea genomes to identify large numbers of SSR markers in the tea. Besides the genomic sequences, we identified SSRs from the other publicly available sequences such as RNA-seq, GSS, ESTs and organelle genomes (chloroplasts and mitochondrial) and also searched published literature to catalog validated set of tea SSR markers. The complete exercise yielded a total of 935 547 SSRs. Out of the total, 82 SSRs were selected for validation among a diverse set of tea genotypes. Six primers (each with four to six alleles, an average of five alleles per locus) out of the total 27 polymorphic primers were used for a diversity analysis in 36 tea genotypes with mean polymorphic information content of 0.61-0.76. Finally, using all the information generated in this study, we have developed a user-friendly database (TeaMiD; http://indianteagenome.in:8080/teamid/) that hosts SSR from all the six resources including three nuclear genomes of tea and transcriptome sequences of 17 Camellia wild species. Database URL: http://indianteagenome.in:8080/teamid/.

Pharmacological evaluation and chemical standardization of an ayurvedic formulation for wound healing activity.

Wound healing is a topic of substantial prominence in Ayurveda, the Indian traditional system of medicine. Test drug Kshatantak Malam (KM), otherwise named as Baharer Nani, is described in Ayurveda since a long time for wound healing activity but necessitates scientific base. The test drug was prepared in the form of natural ointment with the plants like Achyranthes aspera, Allium cepa, and Canabis sativa under the base of butter in a specialized form of preparation. Chemical standardization was made on the basis of the physical character, rancidity test, extractive value, thin-layer chromatography, and gas chromatography. An 8-mm-diameter full-thickness punch was produced in Wistar rats. The test drug was applied topically and compared with standard comparators like framycetin ointment and povidone iodine ointment. Effects were observed on the basis of physical parameters like wound contraction size (mm(2)), wound index, healing period (days), tensile strength (g) and biochemical parameters like tissue DNA (mg/g), RNA (mg/g), total protein (mg/g), hydroxyproline (mg/g), PAGE study, and histopathological observations. Significant results (P < .05) were observed with KM in the punch wound model on the basis of various physical, biochemical, and histopathological parameters. The drug was found to be safe in acute and chronic toxicity models in animals. Chemically it is enriched with fatty substances.

Changes of growth, photosynthesis and alteration of leaf antioxidative defence system of tea [Camellia sinensis (L.) O. Kuntze] seedlings under aluminum stress.

Tea [Camellia sinensis (L.) O. Kuntze] is an aluminum (Al) hyperaccumulator plant and is commercially important due to its high content of antioxidants. Although Al induced growth is well-known for the plants growing in acid soil, yet the cause underlying the stimulatory effect of Al has not been fully understood. To investigate the possible role of Al in growth induction, we studied morphological, physiological as well as biochemical changes of tea plant under different Al concentrations (0-4,000 µM). In hydroponics, Al (15 µM), enhanced shoot and root growth, but at higher concentrations, it caused oxidative damage which culminated in a cascade of biochemical changes, Al content increased concurrently with the maturity of the leaf as well as stem tissues than their younger counterparts. Hematoxylin staining indicated that Al accumulation started after 6 h of exposure in the tips of young roots and accumulation was dose dependent. The physiological parameters such as pigments, photosynthetic rate, transpiration and stomatal conductance were declined due to Al toxicity. Alteration in activated oxygen metabolism was also evidenced by increasing lipid peroxidation, membrane injury, evolution of superoxide anions and accumulation of H(2)O(2). Contents of phenols initially exhibited an acceleration which gradually plummeted at higher levels whereas total sugar and starch contents decimated beyond 15 µM of Al concentration. Activities of antioxidant defense enzymes were increased with the elevated concentration of Al. Expression of citrate synthase gene was up-regulated in the mature leaves, young as well as old roots simultaneously with increased concentration of Al in those parts; indicating the formation of Al-citrate complex. These results cooperatively specified that Al concentration at lower level promoted growth but turned out to be a stressor at elevated stages indicating the sensitivity of the cultivar (T-78) to Al.