Identification of miRNA-eQTLs in maize mature leaf by GWAS

Background MiRNAs play essential roles in plant development and response to biotic and abiotic stresses through interaction with their target genes. The expression level of miRNAs shows great variations among different plant accessions, developmental stages, and tissues. Little is known about the content within the plant genome contributing to the variations in plants. This study aims to identify miRNA expression-related quantitative trait loci (miR-QTLs) in the maize genome. Results The miRNA expression level from next generation sequencing (NGS) small RNA libraries derived from mature leaf samples of the maize panel (200 maize lines) was estimated as phenotypes, and maize Hapmap v3.2.1 was chosen as the genotype for the genome-wide association study (GWAS). A total of four significant miR-eQTLs were identified contributing to miR156k-5p, miR159a-3p, miR390a-5p and miR396e-5p, and all of them are trans-eQTLs. In addition, a strong positive coexpression of miRNA was found among five miRNA families. Investigation of the effects of these miRNAs on the expression levels and target genes provided evidence that miRNAs control the expression of their targets by suppression and enhancement. Conclusions These identified significant miR-eQTLs contribute to the diversity of miRNA expression in the maize penal at the developmental stages of mature leaves in maize, and the positive and negative regulation between miRNA and its target genes has also been uncovered.

Efficacy of Terminalia arjuna mature leaf powder and Phyllanthus emblica bark powder to reduce nitrate: N and total hardness in groundwater in karstified limestone aquifer

Groundwater is a vital resource in the northern region of Sri Lanka, as it is the only water resource used for domestic, agricultural and industrial activities in that area. However, due to excessive usage of synthetic fertilizer, the groundwater in this part of the country is highly contaminated with nitrates. In addition, due to the effect of underlain limestone aquifer, water hardness is also high. The present study aimed to study the effect of filtration through Terminalia arjuna mature leaf powder and Phyllanthus emblica bark powder on reducing nitrate concentration and hardness. The results indicated that 21.4% reduction of nitrate concentration can be achieved by filtration through Terminalia arjuna mature leaf powder and 9.3% reduction of total hardness by filtration through Phyllanthus emblica bark powder. Therefore, further research is recommended on testing the potential and side effects of using Terminalia arjuna mature leaf powder and Phyllanthus emblica bark powder as a combined home remedial treatment technique for treating nitrate contaminated hard water.

Camellia puhoatensis (Sect. Archecamellia – Theaceae), a new species from Vietnam

A new species of Theaceae, Camellia puhoatensis N.S. Lý, V.D. Luong, T.H. Le, D.H. Nguyen & N.D. Do, sp. nov., is described and illustrated from Nghe An Province, North Central Coastal Region, Vietnam. It is most similar to C. chrysanthoides, C. flavida and C. petelotii within sect. Archecamellia in shape and colouration of leaf, petal, ovary and glabrous stamen, but differs by its young puberulous shoot, mature leaf sparsely puberulous abaxially and leaf base rounded or broadly obtuse, petiole and pedicel puberulous, tepals 12–13, ovary and style pubescent. The comparison between the new species and C. velutina and C. dormoyana is presented. Data on distribution, ecology, phenology, use and provisional conservation assessment of the new species are given along with an illustration and a colour plate.

Variation in Macronutrient Content, Phytochemical Constitution and In Vitro Antioxidant Capacity of Green and Red Butterhead Lettuce Dictated by Different Developmental Stages of Harvest Maturity

Rising life expectancy and the demanding modern lifestyle drive the growing appeal of healthy and balanced diets centered on vegetable and fruit consumption. Functional, phytonutrient-packed and principally raw food is in high demand. Microgreens constitute such a novel functional food that combines a high sensory and bioactive value, which invites comparison to their mature-leaf counterparts. For this purpose, a controlled environment chamber experiment was carried out to compare the mineral, phytochemical and antioxidant capacity attributes of two-pigmented Lactuca sativa L. var. capitata cultivars (green and red Salanova®) harvested at the microgreens and the mature-leaf stage. Macronutrients were assessed through ion chromatography, while carotenoids and polyphenols were assessed and quantified through HPLC-DAD and UHPLC-Q-Orbitrap HRMS, respectively. Calcium and magnesium were higher in microgreens irrespective of the cultivar; conversely, phosphorous, potassium and nitrate where higher in mature leaves. All pigments including chlorophyll, lutein and β-carotene augmented at advanced maturity stage and were more concentrated in the red pigmented cultivar at both stages. Total polyphenols accumulated more densely in red Salanova, particularly in the microgreens stage; whereas, in green Salanova, the accumulation was significant but less pronounced in the mcirogreens stage. Chlorogenic acid, quercetin malonyl glucoside, rutin and coumaroyl quinic acid were the most concentrated phenolic acids in microgreens, while feruloyl tartaric acid was predominant in mature leaves. Finally, when a high carotenoids content is sought, mature lettuce leaves should be the prime culinary choice, whereas high polyphenolic content is dictated by both the cultivar and the harvest stage, with red Salanova microgreens being the most nutrient-packed choice.

Phenotypic Characterization of Dioscorea burkilliana J. Miège (Dioscoreaceae) Genetic Resources

Aims: This study investigated morphological characterization of eighty accessions of Dioscorea burkilliana obtained from the Genetic Resources Center of International Institute of Tropical Agriculture (IITA) Ibadan, Nigeria. Study Design and Methods: The experimental field was laid out in a complete randomized design with three replicates on plots of 10 meters length spaced at one meter between rows and one meter within rows (10 m x 1 m x 1 m). Results: The evaluation of nine qualitative and six quantitative traits revealed phenotypic variations in D. burkilliana accessions using IPGRI’s descriptors. The mature stem colour of spot at spine base (MSCSSB) had the highest mean of 61.73 cm, while young stem with absence or presence of scale leaves (YSA/PSL) had least value of 0.37 cm. The principal component analysis (PCA) produced the highest eigenvector of 3.122 for Prin 1 with highest proportion of 20.81%, while Prin 15 had the least (0.11%). Also, in Prin 1, the mature leaf petiole at base (MLP A), mature leaf petiole at middle ( MLP B) and mature leaf petiole at top (MLP C) were closely related compared to matured leaf measurement MLM-Breadth A, MLM-Breadth B and MSA-PCS. There was positive and strong relationship between mature leaf petiole at base (MLP-A) with mature leaf petiole at middle (MLP-B) (r = 0.84, p< 0.005) and mature leaf petiole at top (MLP-C) (r = 0.75). The dendrogram was delineated into seven cluster groups in which cluster V had 18 accessions which was the highest, while cluster VI had the least with one accession (DbB 222). Conclusion: The strong positive associations among MLP-A, MLP-B and MLP-C as well as MSS SAB and MSA/PCS suggested the consideration of these traits for future breedings. Accessions DbB 83, DbB 140 and DbB 254 could be recommended as parent material for the improvement of Discorea burkilliana.

Antioxidant and Glycemic Regulatory Properties Potential of Different Maturity Stages of Leaf of Ceylon Cinnamon (Cinnamomum zeylanicum Blume) In Vitro

Dichloromethane:methanol (1:1, v/v) extracts of different maturity stages (immature, partly mature, and mature) of authenticated leaves of Ceylon cinnamon (CC) were used in this study. Antioxidant properties [total polyphenolic content (TPC) and total flavonoid content (TFC), 1, 1-diphenyl-2-picryl-hydrazyl (DPPH), 2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS)), oxygen radical absorbance capacity (ORAC), and ferric reducing antioxidant power (FRAP)] and glycemic regulatory properties [antiamylase (AA); antiglucosidase (AG)] were evaluated using 96-well microplate based bio assays in vitro (TPC, TFC, DPPH, ABTS, ORAC n=4 each; FRAP, AA, AG n=3 each). Results clearly revealed significant differences (p<0.05) among different maturity stages of leaf of CC for both antioxidant and glycemic regulatory properties (except AG activity). The mean antioxidant and glycemic regulatory activities of immature, partly mature, and mature leaves ranged from TPC: 0.68 ± 0.02–22.35 ± 0.21 mg gallic acid equivalents/g of sample (GS); TFC: 0.85 ± 0.01–4.68 ± 0.06 mg quercetin equivalents/GS; DPPH: 0.42 ± 0.01–27.09 ± 0.65 mg Trolox equivalents (TE)/GS; ABTS: 3.57 ± 0.10–43.91 ± 1.46 TE/GS; ORAC: 0.71 ± 0.01–18.70 ± 0.26 TE/G, FRAP: 0.31 ± 0.02–69.16 ± 0.52 TE/GS; and AA: 18.05 ± 0.24–36.62 ± 4.00% inhibition at 2.5 mg/mL. Mature leaf had the highest antioxidant and AA activities for all the assays investigated. In contrast, immature leaf had the lowest. The order of potency for antioxidant and AA activities was mature leaf > partly mature leaf > immature leaf. This is the first study to report on antioxidant and glycemic regulatory properties of different maturity stages of leaf of Ceylon cinnamon and highlights its potential use in management of oxidative stress-associated chronic diseases including diabetes mellitus.