Determinant Factors and Regulatory Systems for Anthocyanin Biosynthesis in Rice Apiculi and Stigmas

Anthocyanins cause purple, brown or red colors in various tissues of rice plants, but the specific determinant factors and regulatory systems for anthocyanin biosynthesis in almost all tissues remain largely unknown. In the present study, we mapped and isolated two complementary genes, OsC1 encoding a R2R3-MYB transcriptional factor and OsDFR encoding a dihydroflavonol 4-reductase, which are responsible for the purple coloration of apiculi and stigmas in indica cultivar Xieqingzao by the map-based cloning strategy. We also identified two tissue-specific pigmentation genes, OsPa for apiculi and OsPs for stigmas, by phylogenetic analysis of all anthocyanin biosynthesis-associated bHLH transcriptional factors in maize and rice, CRISPR/Cas9 knockout and transcriptional expression analysis. The OsC1, OsPa and OsPs proteins are all localized in the nucleus while the OsDFR protein is localized in the nucleus and cytoplasm, and the OsC1 and OsDFR genes are preferentially strongly expressed in both purple-colored tissues while the OsPa and OsPs genes are preferentially strongly expressed in apiculi and stigmas, respectively. OsC1 specifically interacts with OsPa or OsPs to activate OsDFR and other anthocyanin biosynthesis genes, resulting in purple-colored apiculi or stigmas. OsC1 itself does not produce color but can produce brown apiculi when functioning together with OsPa. Loss of function of OsDFR alone leads to brown apiculi and straw-white stigmas. Genotyping and phenotyping of a panel of 176 rice accessions revealed diverse genotypic combinations of OsC1, OsDFR, OsPa and OsPs that enable accurate prediction of their apiculus and stigma pigmentation phenotypes, thus validating the general applicability of the OsC1-OsDFR-OsPa and OsC1-OsDFR-OsPs models to natural populations. Our findings disclosed the biological functions of OsC1, OsPa and OsPs, and shed light on the specific regulatory systems of anthocyanin biosynthesis in apiculi and stigmas, a further step in understanding the regulatory network of anthocyanin biosynthesis in rice.

Transcriptomic Analysis of the Anthocyanin Biosynthetic Pathway Reveals the Molecular Mechanism Associated with Purple Color Formation in Dendrobium Nestor

Dendrobium nestor is a famous orchid species in the Orchidaceae family. There is a diversity of flower colorations in the Dendrobium species, but knowledge of the genes involved and molecular mechanism underlying the flower color formation in D. nestor is less studied. Therefore, we performed transcriptome profiling using Illumina sequencing to facilitate thorough studies of the purple color formation in petal samples collected at three developmental stages, namely—flower bud stage (F), half bloom stage (H), and full bloom stage (B) in D. nestor. In addition, we identified key genes and their biosynthetic pathways as well as the transcription factors (TFs) associated with purple flower color formation. We found that the phenylpropanoid–flavonoid–anthocyanin biosynthesis genes such as phenylalanine ammonia lyase, chalcone synthase, anthocyanidin synthase, and UDP-flavonoid glucosyl transferase, were largely up-regulated in the H and B samples as compared to the F samples. This upregulation might partly account for the accumulation of anthocyanins, which confer the purple coloration in these samples. We further identified several differentially expressed genes related to phytohormones such as auxin, ethylene, cytokinins, salicylic acid, brassinosteroid, and abscisic acid, as well as TFs such as MYB and bHLH, which might play important roles in color formation in D. nestor flower. Sturdy upregulation of anthocyanin biosynthetic structural genes might be a potential regulatory mechanism in purple color formation in D. nestor flowers. Several TFs were predicted to regulate the anthocyanin genes through a K-mean clustering analysis. Our study provides valuable resource for future studies to expand our understanding of flower color development mechanisms in D. nestor.

Agro-morphological traits and harvest period assessment of winged bean (Psophocarpus tetragonolobus) genotypes for pods production

Ishthifaiyyah SA, Syukur M, Trikoesoemaningtyas, Maharijaya A. 2021. Agro-morphological traits and harvest period assessment of winged bean (Psophocarpus tetragonolobus) genotypes for pods production. Biodiversitas 22: 1069-1075. Winged bean (Psophocarpus tetragonolobus) is an underutilized crop in Indonesia. Winged bean varieties for pods productions not only must have high productivity and nutrient contents, but also have a long harvest period. This research aimed to evaluate agro-morphological traits and harvest period of eighth-generation winged bean genotypes. Twenty genotypes of winged beans were evaluated using randomized complete block design (RCB) with three replications in Bogor, Indonesia. Several qualitative and quantitative traits were evaluated from each genotype. The results showed that there were variations among winged bean genotypes which were based on qualitative traits as well as the color of stem, calyx, corolla, pod, and pod wings. Purple coloration in the calyx of P1 and H3U genotypes was known to correspond with the purple color in stem, corolla, pod, and pod wings. The highest yield among F8 genotypes was found in H2 (6.69 to ha-1), similar to P2. However, the longest harvest period among F8 genotypes was found in H1U-2 (78 days). This study revealed that harvest period had positive correlation with the leaflet size. Based on nutrient content, H3U and L2 were considered as the genotypes with the highest protein and fiber content respectively among F8 genotypes.

Nutraceutical fruit characterization, nutritional aspects and sensory analysis of dovyalis jams

ABSTRACT: The objective of this study is to evaluate the composition, nutritional aspects and sensory analysis of the dovyalis jam. Dovyalis fruits were harvested from 4-year-old plants in the orchard of the Unioeste Experimental Farm. They were collected in the morning in polyethylene boxes, when they were ripe and with a purple coloration from the epicarp, being immediately transported to the Laboratory to prepare the jams. After fruits arrival, they were selected by size, color and weight and then sanitized in running water and the cups of the fruits were removed. The sensory evaluations of the jam samples were performed in a randomized fashion, with 30 volunteer tasters. The tasters were previously advised to evaluate the acceptance of the jams and their purchase intentions. Fruits in natura and dovyalis jam are sources of vitamin C. Dovyalis fruits can be used in the processing, due to its acidity. The jam prepared with dovyalis fruits without epicarp and endocarp, and less sugar, was more appreciated by the tasters.

The Purple Leaf (pl6) Mutation Regulates Leaf Color by Altering the Anthocyanin and Chlorophyll Contents in Rice

The anthocyanin biosynthesis attracts strong interest due to the potential antioxidant value and as an important morphological marker. However, the underlying mechanism of anthocyanin accumulation in plant tissues is not clearly understood. Here, a rice mutant with a purple color in the leaf blade, named pl6, was developed from wild type (WT), Zhenong 41, with gamma ray treatment. By map-based cloning, the OsPL6 gene was located on the short arm of chromosome 6. The multiple mutations, such as single nucleotide polymorphism (SNP) at −702, −598, −450, an insertion at −119 in the promoter, three SNPs and one 6-bp deletion in the 5′-UTR region, were identified, which could upregulate the expression of OsPL6 to accumulate anthocyanin. Subsequently, the transcript level of structural genes in the anthocyanin biosynthesis pathway, including OsCHS, OsPAL, OsF3H and OsF3′H, was elevated significantly. Histological analysis revealed that the light attenuation feature of anthocyanin has degraded the grana and stroma thylakoids, which resulted in poor photosynthetic efficiency of purple leaves. Despite this, the photoabatement and antioxidative activity of anthocyanin have better equipped the pl6 mutant to minimize the oxidative damage. Moreover, the contents of abscisic acid (ABA) and cytokanin (CK) were elevated along with anthocyanin accumulation in the pl6 mutant. In conclusion, our results demonstrate that activation of OsPL6 could be responsible for the purple coloration in leaves by accumulating excessive anthocyanin and further reveal that anthocyanin acts as a strong antioxidant to scavenge reactive oxygen species (ROS) and thus play an important role in tissue maintenance.

Two new species of Meriania (Melastomataceae) from eastern Ecuador

We describe two new species of Meriania (Melastomataceae), Meriania ardyae from Llanganates National Park and Meriania zunacensis from the Río Zuñac Reserve in Ecuador. Meriania ardyae is characterized by dark crimson petals, hypanthium and calyx with a dark purple coloration, young branches and internodes covered with a dense pubescence of violet-black hirsute trichomes and slightly dimorphic stamens. Meriania zunacensis is distinguished by conspicuous interpetiolar flaps, inflorescences with glomerulate flower clusters, large flowers with magenta petals, isomorphic stamens, and a fleshy, strongly curved style.

Evaluation of Anthocyanin Profile, Antioxidant, Cytoprotective, and Anti-Angiogenic Properties of Callistemon citrinus Flowers

Lemon bottlebrush (Callistemon citrinus (Curtis) Skeels) is one of the most common ornamental plants, diffused worldwide, and characterized by the presence of flowers with an intense red/purple coloration. There is increasing interest in the use and application of anthocyanins for their unique structural/chemical features in both food and pharmaceutical applications. RP-HPLC-DAD-ESI-MS/MS analysis of an enriched fraction of acidified methanolic extract of C. citrinus flowers allow the possibility of identifying, for the first time, the presence of four anthocyanins: cyanidin-3,5-O-diglucoside (cyanin), peonidin-3,5-O-diglucoside (peonin), cyanidin-3-O-glucoside, and cyanidin-coumaroylglucoside-pyruvic acid. Moreover, the evaluation of antioxidant and biological potential showed a remarkable activity of this fraction, able to actively scavenge DPPH, AAPH, and ABTS radicals, and to counteract the β-carotene-bleaching. In addition, it protects human mononuclear cells from oxidative injuries and prevents angiogenesis (acting in the range of few μg/ml); furthermore, it does not show significant iron-chelating ability (up to 200 µg/mL). The easy way of cultivation, robustness, and adaptability to different environments make the flowers of this plant a useful source of anthocyanins, with remarkable health promoting properties.

Upregulation of the MYB2 Transcription Factor is Associated with Increased Accumulation of Anthocyanin in the Leaves of Dendrobium bigibbum

Orchids with colorful leaves and flowers have significant ornamental value. Here, we used γ-irradiation-based mutagenesis to produce a Dendrobium bigibbum mutant that developed purple instead of the normal green leaves. RNA sequencing of the mutant plant identified 2513 differentially expressed genes, including 1870 up- and 706 downregulated genes. The purple leaf color of mutant leaves was associated with increased expression of genes that encoded key biosynthetic enzymes in the anthocyanin biosynthetic pathway. In addition, the mutant leaves also showed increased expression of several families of transcription factors including the MYB2 gene. Transient overexpression of D. biggibumMYB2 in Nicotiana benthamiana was associated with increased expression of endogenous anthocyanin biosynthesis genes. Interestingly, transient overexpression of orthologous MYB2 genes from other orchids did not upregulate expression of endogenous anthocyanin biosynthesis genes. Together, these results suggest that the purple coloration of D. biggibum leaves is at least associated with increased expression of the MYB2 gene, and the MYB2 orthologs from orchids likely function differently, regardless of their high level of similarity.

New species of Furculanurida (Collembola, Neanuridae, Pseudachorutinae) from the Luquillo Mountains, Puerto Rico

A new species of Furculanurida is described and illustrated. Furculanurida bistribussp. nov. differs from other species of the genus by the presence of three eyes, three setae on the dens, and the white and purple coloration pattern. A key for identification of the world species of the genus is included.

Micronutrient Biofortification with Fe, Zn and Cu for Enhanced Growth, Increased Yield and High Profitability of Purple Yam

The importance of micronutrient biofortification in improving the growth and yield of crops is needed nowadays due to the rapid decline in crop yield caused by soil infertility and the prevalence of malnutrition among young children. Micronutrients (Fe, Zn, and Cu) were added to NPK fertilizers to investigate their effects on the growth and yield of purple yam tubers and assess the profitability of their addition on yam production. The different treatments used in the study were: T1 control; T = 150-50-150 kg/ha (N-P O - K O); T = T + 8 kg/ha Zn; T = T + 8 kg/ha Fe; = 2 2 5 2 3 2 4 2 and T = T + 8 kg/ha Cu. The results showed that the addition of micronutrients such 5 2 as Fe, Zn, and Cu to NPK fertilizers statistically increased the growth and yield of purple yam. The addition of 8 kg/ha Fe and Cu to 150-50-150 kg/ha N-P O -K O 2 5 2 increased the size of tubers and the intensity of purple coloration. These treatments likewise produced high yields equivalent to 29.39 to 29.83 tons/ha. This was about 129 to 133 percent higher than the control group which yielded only 12.80 tons/ha. Moreover, treatment T which is a combination of 150-50-150 kg/ha N-P O -K O + 8 5 2 5 2 kg/ha Fe, has produced the highest net income of PhP1,420,704.00/ha. This was 155% higher than the net income obtained by the control group that only amounted to PhP 557,790.00.