Purple Leaf Research Articles

The effect of colchicine treatment on phenotype and genotype characteristics of Detam-2 variety of soybean Glycine max

Abstract. Fathurrahman F, Ulpah S, Sodiq NAM, Mahadi I, 2024. The effect of Colchicine treatment on phenotype and genotype characteristics of Detam-2 variety of soybean Glycine max. Biodiversitas 25: 1230-1238. The enhancement of soybean plant mutagenesis to obtain phenotypic and genotypic diversity is essential in agriculture. This study aimed to analyze the effect of colchicine concentration on phenotypic and genotypic characteristics based on RAPD markers of detam-2 variety. The experiments were carried out from January to June 2023 in the experimental farm of the Agriculture Faculty, Universitas Islam Riau, Pekanbaru, Indonesia. Therefore, 600 plants were used, consisting of 200 controls and 400 samples treated with 3,500 ppm of colchicine. The growth parameter was analyzed using a DMRT statistical test at p<0.05, and stomata densities were compared using T-test. The mutant-1 produced the highest yield, a total of 235 pods (with 233 phity pods), seed weighed 93.20 g, which was significantly different from those of controls. Mutant-2 produced the highest dry weight of 100 seeds, which was 12.80 g, with a dry seed weight per plant of 63.30 g. Leaf types in mutant samples varied, including normal, purple leaf stems, and curly leaves. The genotypic study showed that primer OPAA-01 produced a different number of DNA bands. The highest genetic similarity was 0.961 among the controls, while the lowest was 0.451 between mutant-1 and the controls. Based on the results, the dendrogram produced two groups: control and mutant-1.

Utilization of Herbal Medicine for Hemorrhoids

Hemorrhoids is a disease characterized by swollen blood vessels in the rectum or anus. This disease is caused by low consumption of fiber, spicy foods and alcoholic drinks. Symptoms that can be experienced by hemorrhoid sufferers are the appearance of lumps and bleeding when defecating. One treatment for this disease is through the use of herbal medicine, namely purple leaves. The aim of this research is to prove whether people now also use purple leaves as a treatment for hemorrhoids. This type of research is non-experimental using survey methods. The instrument used was a questionnaire. The research results show that the majority of hemorrhoid sufferers (80%) use purple leaves to reduce hemorrhoid symptoms. The price of purple leaf medicine is very competitive with conventional hemorrhoid medicine, so that 52% of hemorrhoid sufferers consume purple leaf regularly (although not when experiencing hemorrhoid symptoms).

Pharmaceutical Properties and Phytochemical Profile of Extract Derived from Purple Leaf Graptophyllum pictum (L.) Griff.

Graptophyllum pictum (L.) Griff is a medicinal shrub belonging to the Acanthaceae family and is traditionally used to treat various diseases. Therefore, this study aimed to evaluate the pharmaceutical properties and phytochemical profiles of the methanolic extract of G. pictum. G. pictum leaves was extracted using methanol. Antioxidant, cytotoxic on Michigan Cancer Foundation-7 (MCF-7) and HepG2, antidiabetic, and antibacterial properties were evaluated in vitro. Chemical profile of the extract was identified through qualitative (for phytochemicals), quantitative (for phenolic and flavonoid content), and gas chromatography-mass spectrometry (GC-MS) analysis. The results showed that the extract had potent antioxidant activity against 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) and 2,2-diphenyl-1-picrylhydrazyl radicals with IC50 values of 49.00 ± 3.20 µg/mL and 70.18 ± 3.27 µg/mL, respectively. It also exhibited cytotoxic effects on human breast (MCF-7) and liver (HepG2) carcinoma cells with growth inhibition percentages of 74.29 ± 1.53% and 64.90 ± 1.94%, respectively. The antidiabetic assay showed that the extract had inhibitory effects on α-glucosidase activity with IC50 value 194.59 ± 15.59 µg/mL, indicating its potential to be developed as an antidiabetic agent. Furthermore, it had antibacterial properties against four test strains, and the highest activity was found against Bacillus subtilis American Type Culture Collection 19659, with minimum inhibitory concentration and minimum bactericidal concentration values of 625 µg/mL and 1250 µg/mL, respectively. Phytochemical tests indicated the presence of alkaloids, flavonoid and terpenoids in the extract, with total phenolic content and total flavonoid content of 41.17 ± 2.38 mg gallic acid equivalents/g and 26.52 ± 0.61 mg quercetin equivalent/g, respectively. GC-MS analysis revealed that it contained several active compounds, including eicosane, 2,4-Di-tert-butylphenol, hentriacontane, tetracosane, octacosane, sulfurous acid, 2-methylhexacosane, docosane, heneicosane, 1-propene-1,2,3-tricarboxylic acid, tributyl ester, and pentacosane. The extract derived from G. pictum leaves was a potential source of therapeutic compounds, particularly for antioxidant, antidiabetic, anticancer, and antibacterial agents.

Uji Aktivitas Antibakteri Ekstrak Etanol Daun Ungu (Graptophyllum pictum (L) Griff) terhadap Pertumbuhan Streptococcus sanguinis

Streptococcus sanguinis has strong adhesion with salivary pellicles which causes other oral bacteria to attach more and has contribution in causing caries and periodontal disease. S. sanguinis mediated the adhesion of S. mutans to dental pellicle receptors so inhibiting the interaction between S. sanguinis and S. mutans would prevent the risk of dental caries. Purple leaf (Graptophyllum pictum) is one of the medicinal plants or natural ingredients that are useful as antibacterials. The purpose of this study was to examine antibacterial activity of purple leaf extract against S. sanguinis. This experimental laboratory study with a pre-posttest control group design was conducted by dilution method on treatment groups, purple leaf extract with concentrations of 25%, 12.5%, 6.25% and 3.12%. Visual and spectrophotometer examination was observed before and after incubation.The result showed that purple leaf extract with concentrations of 6.25% and 3.12% and control + groups had not turbidity and decreased absorbance value. Furthermore, the One Way Anova parametric statistical test and also Post-Hoc Least Significant Difference showed that there were significant differences between the study groups. The purple leaf extract (Graptophyllum pictum L. Griff) had antibacterial activity against S. sanguinis. The antibacterial test for extracts that are dark in color can be continued using the TVC (Total Viable Count) method to provide a quantitative estimate of the concentration of bacterial cells in the sample in units of CFU/ml.

Analysis of flavonoid metabolism of compounds in succulent fruits and leaves of three different colors of Rosaceae

Red flesh apple (Malus pumila var. medzwetzkyana Dieck), purple leaf plum (Prunus cerasifera Ehrhar f), and purple leaf peach (Prunus persica ‘Atropurpurea’) are significant ornamental plants within the Rosaceae family. The coloration of their fruits and leaves is crucial in their appearance and nutritional quality. However, qualitative and quantitative studies on flavonoids in the succulent fruits and leaves of multicolored Rosaceae plants are lacking. To unveil the diversity and variety-specificity of flavonoids in these three varieties, we conducted a comparative analysis of flavonoid metabolic components using ultra-high-performance liquid phase mass spectrometry (UPLC-MS/MS). The results revealed the detection of 311 metabolites, including 47 flavonoids, 105 flavonols, 16 chalcones, 37 dihydroflavonoids, 8 dihydroflavonols, 30 anthocyanins, 14 flavonoid carbon glycosides, 23 flavanols, 8 isoflavones, 11 tannins, and 12 proanthocyanidins. Notably, although the purple plum and peach leaves exhibited distinct anthocyanin compounds, paeoniflorin and corythrin glycosides were common but displayed varying glycosylation levels. While the green purple leaf peach fruit (PEF) and red flesh apple leaf (AL) possessed the lowest anthocyanin content, they exhibited the highest total flavonoid content. Conversely, the red flesh apple fruit (AF) displayed the highest anthocyanin content and a diverse range of anthocyanin glycosylation modifications, indicating that anthocyanins predominantly influenced the fruit's color. Purple PLF, PLL, and PEL showcased varying concentrations of anthocyanins, suggesting that their colors result from the co-color interaction between specific types of anthocyanins and secondary metabolites, such as flavonols, flavonoids, and dihydroflavonoids. This study provides novel insights into the variations in tissue metabolites among Rosaceae plants with distinct fruit and leaf colors.

Transcription factor encoding gene OsC1 regulates leaf sheath color through anthocyanidin metabolism in Oryza rufipogon and Oryza sativa

Carbohydrates, proteins, lipids, minerals and vitamins are nutrient substances commonly seen in rice grains, but anthocyanidin, with benefit for plant growth and animal health, exists mainly in the common wild rice but hardly in the cultivated rice. To screen the rice germplasm with high intensity of anthocyanidins and identify the variations, we used metabolomics technique and detected significant different accumulation of anthocyanidins in common wild rice (Oryza rufipogon, with purple leaf sheath) and cultivated rice (Oryza sativa, with green leaf sheath). In this study, we identified and characterized a well-known MYB transcription factor, OsC1, through phenotypic (leaf sheath color) and metabolic (metabolite profiling) genome-wide association studies (pGWAS and mGWAS) in 160 common wild rice (O. rufipogon) and 151 cultivated (O. sativa) rice varieties. Transgenic experiments demonstrated that biosynthesis and accumulation of cyanidin-3-Galc, cyanidin 3-O-rutinoside and cyanidin O-syringic acid, as well as purple pigmentation in leaf sheath were regulated by OsC1. A total of 25 sequence variations of OsC1 constructed 16 functional haplotypes (higher accumulation of the three anthocyanidin types within purple leaf sheath) and 9 non-functional haplotypes (less accumulation of anthocyanidins within green leaf sheath). Three haplotypes of OsC1 were newly identified in our germplasm, which have potential values in functional genomics and molecular breeding of rice. Gene-to-metabolite analysis by mGWAS and pGWAS provides a useful and efficient tool for functional gene identification and omics-based crop genetic improvement.

Kajian Antioksidan dan Sifat Sensoris Hasil Pengeringan Daun Ungu (Graptophyllum pictum) dengan Mesin Fast Dryer

A purple leaf or possibly called a wungu leaf (Graptophyllum pictum) is a commonly used plant as an herbal medicine. Purple leaves have many benefits, and it is known that one can potentially counteract free radicals caused by high flavonoid compounds. One of the key stages in simplishing is the drying method. The study aims to identify the effects of temperature and long periods of drying as well as variations in temperature and length of time on the flavonoid, the sensory properties (color, scent, taste, and texture), water levels, and rendement on the dried purple leaves using fast dryer. The design of the experiments is a Randomized Block Design (RBD). The first factors are drying temperatures consisting of 45°C (C1), 50°C (C2), and 55°C (C3). The second factors is drying time of 3 hours (F1), 4 hours (F2), and 5 hours (F3). The data analysis is done using a ANOVA and if the results show a real difference then a nt test with a 5% confidence level. Studies indicate that the higher the temperature and time spent in drying, the greater the levels of flavonoid and sensory properties and the lower the water content and rendement in dried purple leaf.

Overexpression of black rice OsC1 confers tissue-specific anthocyanin accumulation in indica rice cv. Kasalath and its potential use as a visible marker in rice transformation

Anthocyanin biosynthesis, a process regulated by distinct MYB and MYC transcription factors, plays a crucial role in determining pigmentation in various tissue of plants. This study aimed to investigate the impact of overexpressing the OsC1 gene from black rice, encoding a MYB transcription factor, on anthocyanin pigmentation in red indica rice cv. Kasalath. Anthocyanin pigmentation was readily observed as purple spots in calli and as purple shoot tips and purple leaf sheath in transgenic seedlings. We confirmed the presence of the transgene using GUS assay and PCR analysis, and the pigmentation segregated following a 3:1 Mendelian ratio. T0 and T1 transgenic plants exhibits anthocyanin accumulation in various tissues including leaf sheaths, auricles, nodes, stigma, apiculus and awns, excluding the pericarp. Notably, the pigmentation in node tissues has not been previously reported for the OsC1 gene, and this gene does not involve in pericarp pigmentation. RT-PCR analysis of transgenic seedlings demonstrated that the overexpression of the OsC1 gene upregulated anthocyanin structural genes, particularly OsDFR, leading to anthocyanin accumulation. Intriguingly, the absence of OsB2 expression, encoding a MYC transcription factor, in transgenic seedlings suggests the involvement of alternative MYC factors in purple leaf sheaths. This study not only expands our understanding of OsC1's role in tissue specific anthocyanin pigmentation but also proposes OsC1 as a potential visible marker in rice transformation. Utilizing OsC1 as a marker provides an alternative approach to address concerns related to antibiotic-resistant genes while providing visually striking pigmentation.

Physiological Responses and Salt Tolerance Evaluation of Purple-Leaf Berberis (Berberis thunbergii var. Atropurpurea) and Glacier Red-Leaf Berberis (Berberis thunbergii) Under NaCl Stress

This study investigated the impact of various concentrations of NaCl stress treatment (0%, 0.1%, 0.2%, 0.3%, 0.4%) on the growth of one-year-old saplings of purple leaf barberry and glacier red leaf barberry. It also examined the impact on various physiological responses including plasma membrane permeability, antioxidant protective enzyme system, osmotic regulatory substance content, photosynthetic characteristics, ion content, and the ultrastructure of leaf cells using transmission electron microscopy. The goal was to determine the salt tolerance threshold and elucidate the physiological response mechanism to NaCl stress. The comprehensive assessment of salt tolerance in the two barberries was done using fuzzy membership functions. The results demonstrated that increasing concentrations of NaCl stress and longer treatment durations led to gradual decreases in sapling growth and increases in salt damage index. The salt tolerance thresholds were calculated to be 0.37% for purple leaf barberry and 0.33% for glacier red leaf barberry using the logistic curve equation. The activities of SOD and POD initially increased and then decreased in both barberries. Furthermore, MDA, free proline, and Na+ content gradually increased, while soluble protein content, chlorophyll content, net photosynthetic rate (Pn), K+ content, and K+/Na+ ratio gradually decreased. The purple leaf barberry displayed larger and deformed chloroplasts with significant separation of quality and wall, whereas the glacier red leaf barberry experienced a gradual decrease in chloroplast size and number until degradation. The membership function analysis revealed that purple leaf barberry exhibited superior resistance compared to glacier red leaf barberry.

The anthocyanin formation of purple leaf is associated with the activation of LfiHY5 and LfiMYB75 in crape myrtle

Purple-leafed plants not only have a higher resistance to biotic and abiotic stresses, but also have higher ornamental value. Anthocyanins are vital for leaf color formation, growth and development of purple leaves. However, the molecular mechanism underlying purple leaf formation in Lagerstroemia indica remains unclear. Metabolomic and transcriptomic analysis of purple-leafed cultivar ‘Ebony Embers’ and green-leafed cultivar ‘Arapahoe’ showed that the high expression of anthocyanin structure genes induced hyperaccumulation of cyanidin and pelargonidin derivatives, making the leaves purple. LfiHY5, LfiMYB75 and LfibHLH1 were identified using correlation analysis and weighted gene co-expression network analysis. In ‘Arapahoe’ × ‘Ebony Embers’ population, LfiHY5 and LfiMYB75 showed significant positive correlation with leaf anthocyanin content. Transient expression of LfiMYB75 and LfiHY5 in tobacco and purple-leafed crape myrtle indicated that the two genes activated anthocyanin synthesis. Yeast two-hybrid analysis showed that LfiMYB75 and LfibHLH1 could form a complex that enhanced anthocyanin synthesis. Yeast monohybrid and dual-luciferase assays confirmed that LfiHY5 activated the expression of LfiMYB75, to activate the transcription of anthocyanin structural genes LfiCHS and LfiANS. Moreover, there were three alleles of LfiHY5 in crape myrtle, and the different sequences had different activation effects on LfiMYB75. In conclusion, the results showed that LfiHY5 led to upregulate the transcription of LfiMYB75, and LfiMYB75 formed a complex with LfibHLH1, which increased the transcription level of LfiCHS and LfiANS to affect anthocyanin synthesis in crape myrtle.

Comparative Metabolomics Analysis of Different Perilla Varieties Provides Insights into Variation in Seed Metabolite Profiles and Antioxidant Activities.

Perilla seeds are essential functional foods and key ingredients in traditional medicine. Herein, we investigated the variation in phytochemical profiles and antioxidant activities of twelve different perilla seeds. The seeds showed significant variations in total phenolic and flavonoid contents ranging from 16.92 to 37.23 mg GAE/g (GAE, gallic acid equivalent) and 11.6 to 19.52 mg CAE/g (CAE, catechin equivalent), respectively. LC-QqQ-MS (liquid chromatography triple quadrupole tandem mass spectrometry)-based widely targeted metabolic profiling identified a total of 975 metabolites, including 68-269 differentially accumulated metabolites (DAMs). Multivariate analyses categorized the seeds into four groups based on the seed coat and leaf colors. Most key bioactive DAMs, including flavonoids (quercetin-3'-O-glucoside, prunin, naringenin, naringenin chalcone, butin, genistin, kaempferol-3-O-rutinoside, etc.), amino acids (valine, lysine, histidine, glutamine, threonine, etc.), and vitamins (B1, B3, B6, U, etc.) exhibited the highest relative content in PL3 (brown seed, purple leaf), PL1 (white seed, green-purple leaf), and PL4 (white seed, green leaf) groups, respectively. Meanwhile, key differentially accumulated phenolic acids showed a higher relative content in PL1 and PL4 than in other groups. Both seeds exhibited high antioxidant activities, although those of PL2 (brown seed, green leaf) group seeds were the lowest. Our results may facilitate the comprehensive use of perilla seeds in food and pharmaceutical industries.

Appropriate Nitrogen form Ratio and UV-A Supplementation Increased Quality and Production in Purple Lettuce (Lactuca sativa L.)

Purple lettuce (Lactuca sativa L. cv. Zhongshu Purple Lettuce) was chosen as the trial material, and LED intelligent light control consoles were used as the light sources. The purpose was to increase the yield and quality of purple lettuce while lowering its nitrate level. By adding various ratios of NO3−-N and NH4+-N to the nutrient solution and 20 µmol m−2 s−1 UV-A based on white, red, and blue light (130, 120, 30 µmol m−2 s−1), the effects of different NO3−-N/NH4+-N ratios (NO3−-N, NO3−-N/NH4+-N = 3/1, NH4+-N) and UV-A interaction on yield, quality, photosynthetic characteristics, anthocyanins, and nitrogen assimilation of purple lettuce were studied. In order to produce purple lettuce hydroponically under controlled environmental conditions, a theoretical foundation and technological specifications were developed, taking into account an appropriate UV-A dose and NO3−-N/NH4+-N ratio. Results demonstrate that adding a 20 µmol m−2 s−1 UV-A, and a NO3−-N/NH4+-N treatment of 3/1, significantly reduced the nitrate level while increasing the growth, photosynthetic rate, chlorophyll, carotenoid, and anthocyanin content of purple lettuce. The purple leaf lettuce leaves have an enhanced capacity to absorb nitrogen. Furthermore, plants have an acceleration of nitrogen metabolism, which raises the concentration of free amino acids and soluble proteins and promotes biomass synthesis. Thus, based on the NO3−-N/NH4+-N (3/1) treatment, adding 20 µmol m−2 s−1 UV-A will be helpful in boosting purple lettuce production and decreasing its nitrate content.

The Purple leaf (Pl) Alleles, Plw and Pli, Regulate Leaf Color Development Independently from the Pb Gene of Purple pericarp (Prp) in Rice

Color development in various rice organs results from the complementary expression of genes involved in anthocyanin biosynthesis. The Purple pericarp (Prp) trait and the Purple leaf (Pl) trait both display epistasis, relying on the complement of the Pb and Pp genes for pericarp coloration and the Pl and Pp genes for leaf coloration, respectively. However, there is still genetic uncertainty in identifying the genes responsible for the various color expressions and intensities of rice grain pericarp and leaves. In this study, we characterized the inheritance patterns of color development and the mode of anthocyanin pigments in rice by crossing two parental mutant lines. YUM051, exhibiting dark purple leaves (Plw) and purple pericarp (Prp), was crossed with YUM144, which displayed light purple leaves (Pli) and a white pericarp (prp). The F1 plants exhibited dark purple leaves with purple pericarps, indicating the dominant nature of the purple leaf (Pl) and purple pericarp (Prp) traits. The rice Prp traits display a complementary interaction, reflected in a 9:7 ratio of purple to white pericarp. However, the Prp trait followed Mendelian segregation with a 3:1 ratio of purple to white pericarp in this cross, indicating homozygous dominant Pp alleles in both parental plants. Meanwhile, the segregation of the purple leaf color in the F2 generation of this cross followed complementary inheritance, exhibiting a 9:7 segregation ratio between purple leaves and greenish leaves with purple leaf margins. Moreover, the co-segregation of Prp and Pl traits in the cross between YUM051 (Plw) and YUM144 (Pli) plants did not adhere to the Mendelian 9:3:3:1 independent assortment ratio, confirming that the Pl gene and Pb gene are linked on the same chromosome. Cyanidin-3-O-glucoside (C3G) was detected in the leaves of all progeny resulting from the Plw and Pli cross. However, C3G was exclusively identified in the seeds of offspring carrying the dominant Pb gene. Therefore, the Plw and Pli alleles are Pl genes responsible for purple leaf color, while the Pb gene is responsible for purple pericarp color in rice; these genes function independently of each other.

Differences in particulate matter retention and leaf microstructures of 10 plants in different urban environments in Lanzhou City.

Particulate matter (PM) is a major primary environmental air pollutant and poses a threat to human health. Differences in the environment and leaf microstructures of plants will result in varying abilities to retain PM, but the effects of changes in these factors on PM retention are not yet well understood. This study selected 10 plant species in four urban areas (sports field, park, residential green space, and greenway) as the study objects. The amount of retained PM by the different species was measured, and the leaf microstructures were observed. It was found that the environment significantly affected both PM retention and leaf microstructure. The ranking of PM retention in the 10 species in four areas was greenway > residential green space > park > sports field. The ranking of average stomatal width and length was park > sports field > residential green space > greenway, while that of average stomatal density was greenway > residential green space > park > sports field. Different environments affected the length and density of trichomes in the leaves. These changes represented the adaptation of plant species to the growth environment. The stomata and grooves of the leaf surface significantly affected the ability of plants to retain PM. The amount of PM retained by different species varied. In all four urban areas, Prunus × cistena N. E. Hansen ex Koehne (purple leaf sand cherry), Prunus cerasifera Ehrhart f. atropurpurea (Jacq.) Rehd. (cherry plum), Buxus sinica var. parvifolia M. Cheng (common boxwood), and Ligustrum × vicaryi Rehder (golden privet) showed strong PM retention. The results of this study will provide information for planners and urban managers for the selection of plant species.

Integrated Transcriptome and Metabolome Analysis Revealed the Molecular Mechanism of Anthocyanin Synthesis in Purple Leaf Pepper (Capsicum annuum L.) under Different Light Intensities

Light is a crucial environmental component for plant growth, and light intensity plays a crucial function in controlling pigment anabolism in plants. We performed physiological characterisation, transcriptome, and metabolome investigations on purple leaf peppers treated with different light intensities to evaluate the effect on plant leaf colour. The results showed that the leaves of the peppers became significantly purplish under high light, with significantly higher anthocyanin, chlorophyll a, and carotenoid contents. A total of 44,263 genes were quantified using RNA-Seq, with the photoprotein-related genes LRP and LIP maintaining high expression levels under high and medium light. The anthocyanin synthesis pathway was variously enriched among the comparison groups, according to KEGG. The expression of the genes involved in the anthocyanin synthesis pathway, such as CHI, F3H, DFR, and BZ1, was significantly higher under high light. In addition, MYB and bHLH gene families were the most abundant, and MYB1R1, MYB113-like, and bHLH90-like were significantly expressed under high light and highly positively correlated with the above anthocyanin synthesis genes. According to our metabolomic analysis, delphinidin-3-O-rutinoside and delphinidin-3-O-glucoside accumulated in significant concentrations in purple leaves under high light. This study is useful for understanding the process of anthocyanin synthesis and metabolism in pepper leaves that is generated and regulated by varied light intensity.

How monochromatic and composed light affect the kale ‘Scarlet’ in its initial growth stage

Interest in vegetables at their microgreen stage, especially those from the Brassicaceae family, has constantly grown due to their numerous health-promoting compounds. Brassica oleracea convar. acephala var. sabellica cv. Scarlet with purple leaf discolouration was used in the study. Four LED lighting treatments were applied: white light (control), monochromatic blue (430 nm), monochromatic red (660 nm) and purple, i.e., blue (30% in spectrum, 430 nm) mixed with red (70%, 620 nm and 660 nm in equal shares). Photosynthetic photon flux density (PPFD) was 100 µmol m–2 s–1, photoperiod – 16 h light. The purple light promoted the cotyledon growth but decreased the soluble sugars content. The blue light significantly enhanced the anthocyanins synthesis and the radical scavenging activity (RSA). While under white light, the highest concentration of free amino acids and the lowest RSA were observed. As regards the phenolic compounds and photosynthetic pigments content, the reaction of kale to white light was similar to those observed under the purple and red light conditions. The experiment discussed here is of great practical importance and reveals the need for more in-depth research.

Identification and characterization of the gene BraANS.A03 associated with purple leaf color in pak choi (Brassica rapa L. ssp. chinensis).

BraANS.A3 was the key gene controlling purple leaf color in pak choi, and two short fragments of promoter region in green pak choi might be interfering its normal expression. Pak choi (B. rapa L. ssp. chinensis) is an influential and important vegetable with green, yellow, or purple leaves that is cultivated worldwide. The purple leaves are rich in anthocyanins, but the underlying genetics and evolution have yet to be extensively studied. Free-hand sections of the purple leaves indicated that anthocyanins mainly accumulate throughout the adaxial and abaxial epidermal leaf cells. Segregation analyses of an F2 population of a B. rapa ssp. chinensis L. purple leaf mutant ZBC indicated that the purple trait is controlled by an incompletely dominant nuclear gene. Bulked segregant analysis (BSA) showed that the key genes controlling the trait were between 24.25 and 38.10Mb on chromosome A03 of B. rapa. From the annotated genes, only BraA03g050560.3C, homologous to Arabidopsis AtANS, was related to the anthocyanin synthesis pathway. Genome annotation results and transcriptional sequencing analyses revealed that the BraANS.A3 gene was involved in the purple leaf trait. qRT-PCR analyses showed that BraANS.A3 was highly upregulated in ZBC but hardly expressed in the leaves of an inbred homozygous line of B. campestris ssp. chinensis L. green leaf mutant WTC, indicating that BraANS.A3 played a key role catalyzing anthocyanin synthesis in ZBC. Full-length sequence alignment of BraANS.A3 in WTC and ZBC showed that it was highly conserved in the gene region, with significant variation in the promoter region. In particular, the insertion of two short fragments of the promoter region in WTC may interfere with its normal expression. The promoter regions of ANS in six Brassica species all had multiple cis-elements involved in responses to abscisic acid, light, and stress, suggesting that ANS may be involved in multiple metabolic pathways or biological processes. Protein-protein interactions predicted that BraANS.A3 interacts with virtually all catalytic proteins in the anthocyanin synthesis pathway and has a strong relationship with Transparent Testa 8 (TT8). These results suggest that BraANS.A3 promotes anthocyanin accumulation in purple pak choi and provide new insights into the functional analysis of anthocyanin-related genes in Chinese cabbage and transcriptional regulatory networks.

Integrative analysis of metabolome and transcriptome reveals the mechanism of color formation in cassava (Manihot esculenta Crantz) leaves.

Cassava (Manihot esculenta Crantz) leaves are often used as vegetables in Africa. Anthocyanins possess antioxidant, anti-inflammatory, anti-cancer, and other biological activities. They are poor in green leaves but rich in the purple leaves of cassava. The mechanism of anthocyanin's accumulation in cassava is poorly understood. In this study, two cassava varieties, SC9 with green leaves and Ziyehuangxin with purple leaves (PL), were selected to perform an integrative analysis using metabolomics and transcriptomics. The metabolomic analysis indicated that the most significantly differential metabolites (SDMs) belong to anthocyanins and are highly accumulated in PL. The transcriptomic analysis revealed that differentially expressed genes (DEGs) are enriched in secondary metabolites biosynthesis. The analysis of the combination of metabolomics and transcriptomics showed that metabolite changes are associated with the gene expressions in the anthocyanin biosynthesis pathway. In addition, some transcription factors (TFs) may be involved in anthocyanin biosynthesis. To further investigate the correlation between anthocyanin accumulation and color formation in cassava leaves, the virus-induced gene silencing (VIGS) system was used. VIGS-MeANR silenced plant showed the altered phenotypes of cassava leaves, partially from green to purple color, resulting in a significant increase of the total anthocyanin content and reduction in the expression of MeANR. These results provide a theoretical basis for breeding cassava varieties with anthocyanin-rich leaves.

First Report of Nalanthamala psidii causing wilt disease of guava in Guangdong, China.

Guava (Psidium guajava L.) is a tropical fruit with great economic value. Guangdong is one of the most important guava production areas. In November 2019, guava wilt disease (GWD) was observed in a 10.6 HA commercial orchard in NanSha district, Guangzhou, Guangdong (22°37'37.626" N, 113°35'56.089" E). Disease incidence was up to 35%. Initially, leaves on the top of some branches became purple or yellow interveinal chlorosis, later dry. Infection severely became systemic developing vascular discoloration of stem, black root rot, eventually entire trees wilted and died. The root tissues were cut into 5-mm2 pieces and surface disinfected with 70% ethanol for 30 sec, 3 % sodium hypochlorite for 4 min, rinsed by the sterile water, then plated onto potato dextrose agar and incubated for 5 days at 25°C. A total of 8 monoconidial isolates with identical colony morphology were obtained. All formed cottony, whitish to pale yellow colonies. Conidiophores were dimorphic, penicillate and acremonium-like. Penicillate conidiophores gave rise to ovoidal, one-celled conidia (4.15 to 6.55×2.28 to 4.61 μm) (n=100) with truncated ends. Cylindrical or fusiform conidia (7.02 to 15.57×2.01 to 5.30 μm) (n=100) arose in long chains on acremonium-like conidiophores. Morphological characteristics of the isolates were consistent with those of Nalanthamala psidii (syn. Myxosporium psidii) reported by Schroers (2005). The rDNA internal transcribed spacer (ITS) and partial nuclear large-subunit ribosomal DNA (LSU) of two representative isolates (GDNS02 and GDNS08) were amplified using the primers pairs ITS4/ITS5 (White et al. 1990) and V9G/LR5 (de Hoog and Gerrits van den. 1998), respectively. The obtained sequences were deposited in GenBank under the accession nos. OM278372 to 73 (ITS) and OM278377 to 78 (LSU). BLASTn analysis showed 99.81% and 100% identities with the reported sequences of N. psidii CBS 116952 (AY864836) and CBS 110507 (AY554243). Maximum likelihood analyses of combined ITS and LSU sequences indicated that these two isolates being clustered with N. psidii strains. Pathogenicity tests were performed twice using healthy seedlings (60-70 cm height, cv. pearl). Each stem of five seedlings was wounded using a 5-mm sterile cork borer, and 5-day-old mycelium plugs of isolate GDNS08 were inoculated into the holes (25-cm above the soil line) and covered with Parafilm, sterile PDA plugs were placed into the wounds of additional 5 control seedlings. All plants were kept in a greenhouse (25℃, 80% relative humidity, 16/8-h day/night). After 3 months, all inoculated plants developed purple leaf, defoliation and wilt symptoms resembling those observed in the orchards, while the controls remained asymptomatic. Nalanthamala psidii was reisolated from the roots tissue of the inoculated plants, identity was confirmed by morphological characteristics and ITS sequence analyses as described above, but not from the controls, fulfilling Koch's postulates. Nalanthamala psidii has been previously reported as the causal agent of guava wilt in Taiwan, Philippines, South Africa and Bangladesh (Hsieh et al. 1976; Opina 1995; Schoeman et al. 1997; Alam et al. 2019). To our knowledge, this is the first report of N. psidii causing guava wilt in Guangdong, China. The outbreak of GWD in South Africa in the 1980s resulted in devastating losses to guava industry (Schoeman et al. 1997). Further research is needed to develop the integrated management to constrain this disease from spreading.

Comparative transcriptome sequencing analysis to postulate the scheme of regulated leaf coloration in Perilla frutescens.

Perilla as herb, ornamental, oil and edible plant is widely used in East Asia. Until now, the mechanism of regulated leaf coloration is still unclear. In this study, four different kinds of leaf colors were used to measure pigment contents and do transcriptome sequence to postulate the mechanism of leaf coloration. The measurements of chlorophyll, carotenoid, flavonoid, and anthocyanin showed that higher contents of all the aforementioned four pigments were in full purple leaf 'M357', and they may be determined front and back leaf color formation with purple. Meanwhile, the content of anthocyanin was controlled back leaf coloration. The chromatic aberration analysis and correlative analysis between different pigments and L*a*b* values analysis also suggested front and back leaf color change was correlated with the above four pigments. The genes involved in leaf coloration were identified through transcriptome sequence. The expression levels of chlorophyll synthesis and degradation related genes, carotenoid synthesis related genes and anthocyanin synthesis genes showed up-/down-regulated expression in different color leaves and were consistent of accumulation of these pigments. It was suggested that they were the candidate genes regulated perilla leaf color formation, and genes including F3'H, F3H, F3',5'H, DFR, and ANS are probably important for regulating both front and back leaf purple formation. Transcription factors involved in anthocyanin accumulation, and regulating leaf coloration were also identified. Finally, the probable scheme of regulated both full green and full purple leaf coloration and back leaf coloration was postulated.