Purple Leaf Research Articles

Comprehensive analysis of metabolome and transcriptome reveals the mechanism of color formation in different leave of Loropetalum Chinense var. Rubrum

BackgroundLoropetalum chinense var. rubrum (L. chinense var. rubrum) is a precious, coloured-leaf native ornamental plant in the Hunan Province. We found an L. chinense var. rubrum tree with three different leaf colours: GL (green leaf), ML (mosaic leaf), and PL (purple leaf). The mechanism of leaf coloration in this plant is still unclear. Therefore, this study aimed to identify the metabolites and genes involved in determining the colour composition of L. chinense var. rubrum leaves, using phenotypic/anatomic observations, pigment content detection, and comparative metabolomics and transcriptomics.ResultsWe observed that the mesophyll cells in PL were purple, while those in GL were green and those in ML were a mix of purple-green. The contents of chlorophyll a, b, carotenoids, and total chlorophyll in PL and ML were significantly lower than those in GL. While the anthocyanin content in PL and ML was significantly higher than that in GL. The metabolomics results showed the differences in the content of cyanidin 3-O-glucoside, delphinidin 3-O-glucoside, cyanidin 3,5-O-diglucoside, pelargonidin, and petunidin 3,5-diglucoside in ML, GL, and PL were significant. Considering that the change trend of anthocyanin content change was consistent with the leaf colour difference, we speculated that these compounds might influence the colour of L. chinense var. rubrum leaves. Using transcriptomics, we finally identified nine differentially expressed structural genes (one ANR (ANR1217); four CYP75As (CYP75A1815, CYP75A2846, CYP75A2909, and CYP75A1716); four UFGTs (UFGT1876, UFGT1649, UFGT1839, and UFGT3273) and nine transcription factors (two MYBs (MYB1057 and MYB1211), one MADS-box (MADS1235), two AP2-likes (AP2-like1779 and AP2-like2234), one bZIP (bZIP3720), two WD40s (WD2173 and WD1867) and one bHLH (bHLH1631) that might be related to flavonoid biosynthesis and then impacted the appearance of colour in L. chinense var. rubrum leaves.ConclusionThis study revealed potential molecular mechanisms associated with leaf coloration in L. chinense var. rubrum by analyzing differential metabolites and genes related to the anthocyanin biosynthesis pathway. It also provided a reference for research on leaf colour variation in other ornamental plants.

Genotypic effects on the response of soybean (Glycine max (L.) Merrill) to sulfonylurea herbicides

AbstractSulfonylurea (SU) herbicides registered for use in other crops in Australia may leave residues in the soil interrupting rotations involving soybean. However, two unlinked genes (ALS1 and ALS2) confer SU tolerance in soybean. Here, we report experiments that explored the effectiveness of these ALS genes in Australian soybean germplasm. The first two experiments assessed the tolerance to halosulfuron‐methyl or metsulfuron‐methyl of lines with either zero ALS gene (ALS1) or both ALS1 and ALS2 in five different Australian genetic backgrounds. The presence of both ALS1 and ALS2 conferred strong SU tolerance at herbicide application rates as high as four times (4×) the recommended field rate, with evidence of interaction with the genetic background; lines carrying only ALS1 also performed well but demonstrated less tolerance. For the third experiment, the five lines homozygous for both ALS genes were intercrossed in a half‐diallel mating design. The resulting F2 population were screened for tolerance to metsulfuron‐methyl herbicide. In all instances, the presence of the two ALS genes provided absolute protection for the growth tip. Analyses of seedling dry weight and purple leaf discoloration demonstrated significant differences among the crosses. For dry weight, high and significant heritability estimates indicated significant additional genetic variation for SU tolerance in five of the 10 F2 crosses (p ≤ 0.05). The results of these three studies confirm that two ALS genes confer tolerance to SU herbicides when crossed into Australian soybean germplasm, but suggest possible epistatic effects within different backgrounds, and the possibility of other (minor) genes conferring additional SU tolerance.

The Flavonoid Biosynthesis and Regulation in Brassica napus: A Review

Brassica napus is an important crop for edible oil, vegetables, biofuel, and animal food. It is also an ornamental crop for its various petal colors. Flavonoids are a group of secondary metabolites with antioxidant activities and medicinal values, and are important to plant pigmentation, disease resistance, and abiotic stress responses. The yellow seed coat, purple leaf and inflorescence, and colorful petals of B. napus have been bred for improved nutritional value, tourism and city ornamentation. The putative loci and genes regulating flavonoid biosynthesis in B. napus have been identified using germplasms with various seed, petal, leaf, and stem colors, or different flavonoid contents under stress conditions. This review introduces the advances of flavonoid profiling, biosynthesis, and regulation during development and stress responses of B. napus, and hopes to help with the breeding of B. napus with better quality, ornamental value, and stress resistances.

Effects of LED light intensity on purple leaf lettuce seedlings

<p>To explore the light intensity suitable for the growth of purple leaf lettuce seedlings in plant factories and greenhouses, the effects of light intensity of 6000, 12,000, 18,000, 24,000, and 30,000 lx on growth morphology, nutritional quality, photosynthetic pigment, and photosynthetic characteristics of purple leaf lettuce seedlings were studied with ‘Beizisheng 3’ as the experimental material under the condition of white light quality unchanged. The results showed that under a light intensity of 30,000 lx, purple leaf lettuce seedlings grew well, and the biomass, chlorophyll a content, chlorophyll b content, carotenoid content, total chlorophyll, soluble protein content, soluble sugar content, vitamin C content, anthocyanin content, net photosynthetic rate, transpiration rate, and stomatal conductance were the largest, while the nitrate content and intercellular CO<sub>2</sub> concentration were the lowest. However, chlorophyll b content, carotenoid content, soluble protein content, and transpiration rate had no significant difference compared with those under 24000 lx light intensity, and the plant height was the highest under 24,000 lx light intensity. Under the condition of white light quality, the most suitable light intensity for the growth of purple leaf lettuce seedlings is 30,000 lx.</p>

Phytochemical Test and Acute Safety Evaluation of Oral Purple Leaves (Graptophyllum Pictum L. Griff) Extract in Rats

Background: Purple leaves (Graptophyllum pictum (L) Griff) is a native plant from Indonesia (Polynesia) which is empirically common used to treat hemorrhoids, diabetes, and many other diseases. Despite its massive development globally, there are few studies have written about the toxicity of this herbal medicine. Aim: The aim of this study is to describe the acute toxicity of this herbal medicine, as the basic ground of the further safe development of this medicine. Method: Each purple leaf dry powder (2 kg) was extracted with 15 L of 70% ethanol and 15 L of hexane by maceration method for 3 days at room temperature and then filtered to obtain macerate liquid. The study was conducted on 36 male 6-8 weeks, Sprague–Dawley (SD) rats. The result was presented as the mean value ± standard deviation (SD). Data were evaluated for homogeneity using Saphiro Wilk. The comparisons between pre dan post treatment body weight were measured by paired student t test and hematological measurements were analyzed by ANOVA. P value less than 0.05 was considered significant. Results: Acute toxicity of ethanol and hexane extract were assessed following a single dose administered by gavage at a dose of 50, 2000 and 3000 g/kg bw. The mean body weight of rats increased from 150 ± 2.22 g to 161 ± 6.68 g during the 14 days. The difference of body weight between before and at 14 days amongs groups were significantly different with P value <0.01. Conclusion: The present study showed that hexane extract contains more valuable components for medical treatment purposes. The acute toxicity on 50, 2000,3000 kg/BW oral ethanol and hexane extract of Graptophyllum pictum showed no significant influence on hematological blood parameters of rats. It is safe to administered orally ethanol or hexane extract of G. pictum below 3000mg/kgBW rats.

Integrated Analysis of Transcriptome and Metabolome Reveals New Insights into the Formation of Purple Leaf Veins and Leaf Edge Cracks in Brassica juncea.

Purple leaf veins and leaf edge cracks comprise the typical leaf phenotype of Brassica juncea; however, the molecular mechanisms and metabolic pathways of the formation of purple leaf veins and leaf edge cracks remain unclear. In this study, transcriptome and metabolome analyses were conducted to explore the regulation pathway of purple leaf vein and leaf edge crack formation based on four mustard samples that showed different leaf colors and degrees of cracking. The results showed genes with higher expression in purple leaf veins were mainly enriched in the flavonoid biosynthesis pathway. Integrating related genes and metabolites showed that the highly expressed genes of ANS (BjuA004031, BjuB014115, BjuB044852, and BjuO009605) and the excessive accumulation of dihydrokaempferol and dihydroquercetin contributed to the purple leaf veins by activating the synthetic pathways of pelargonidin-based anthocyanins and delphinidin-based anthocyanins. Meanwhile, “alpha-farnesene synthase activity” and “glucan endo-1, 3-beta-D-glucosidase activity” related to the adversity were mainly enriched in the serrated and lobed leaves, indicating that the environmental pressure was the dominant factor controlling the change in leaf shape. Overall, these results provided new insights into the regulation pathways for formation of purple leaf veins and leaf edge cracks, which could better accelerate the theoretical research on purple leaf vein color and leaf edge cracks in mustard.

The Combined Analysis of Transcriptome and Metabolome Provides Insights into Purple Leaves in Eruca vesicaria subsp. sativa

Background: Arugula is an essential oil crop of cruciferous species worldwide and serves as a salad vegetable. Purple plant leaves provide nutrients benefiting human beings and are mainly attributed to high anthocyanins. In this study, we collected a purple arugula cultivar with purple leaves and a green arugula with green leaves. The genetic bases and mechanisms underlying purple leaf formation in arugula remain unclear. Therefore, we conducted integrative metabolomics and transcriptomics of two arugula cultivars with different leaf colors. Methods: To study the underlying mechanisms, transcriptomic and metabolomic analyses were carried out. Results: Metabolomic analysis revealed that 84 of 747 metabolites were significantly differentially expressed, comprising 30 depleted and 49 enriched metabolites. Further analysis showed that cyanidin is the main components responsible for the purple color. A total of 144,790 unigenes were obtained by transcriptomic analysis, with 13,204 unigenes differentially expressed, comprising 8120 downregulated and 5084 upregulated unigenes. Seven structural genes, PAL, C4H, 4CL, CHS, CCoAOMT, LDOX, and UFGT, were identified as candidate genes associated with anthocyanin accumulation through combined analysis of transcriptome and metabolome. Conclusions: Collectively, the differences in the expression levels of PAL, C4H, 4CL, CHS, CCoAOMT, LDOX, and UFGT might be responsible for purple leaf coloration, providing important data for the discovery of candidate genes and molecular bases controlling the purple leaves in arugula.

A NEW DISEASE PROBLEM INDUCED BY CHANGING CLIMATE IN WESTERN ROMANIA

The paper presents results regarding the new winter wheat disease present with great intensity in the north-west Romania during the year 2020. In the climatically changing context, viruses of poaceae affected with intensity the wheat, with a severe reduction of yield. The paper presents the symptoms of bydv during of the phenological stage: yellowing of leave, margins shading leaves, purple leaf coloration, blackened of plant. An unusual positive correlation was point out between purple leaf coloration, caused by virus, and percent of total protein content. some genotypes (Bogdana, Ursita, and Abundent) seems to have some resistance to virus. The best entries have either Otilia or the line f.00628g34 (derived from a triticale/wheat cross), or both in their pedigrees.

Unraveling the Mechanism of Purple Leaf Formation in Brassica napus by Integrated Metabolome and Transcriptome Analyses.

Brassica napus as both oilseed and vegetable, is widely cultivated in China. The purple leaf of B. napus is rich in anthocyanins and can provide valuable nutrients. Although several high-anthocyanin cultivars have been reported, the molecular mechanism underlying anthocyanin biosynthesis in B. napus remains lesser-known. Therefore, in this study, we conducted integrative metabolome and transcriptome analyses in three B. napus cultivars with different leaf colors. Overall, 39 flavonoids were identified (including 35 anthocyanins), and 22 anthocyanins were differentially accumulated in the leaves, contributing to the different leaf colors. Cyanidin-3,5,3’-O-triglucoside was confirmed as the main contributor of the purple leaf phenotype. Meanwhile, other anthocyanins may play important roles in deepening the color of B. napus leaves. A total of 5,069 differentially expressed genes (DEGs) and 32 overlapping DEGs were identified by RNA-sequencing; hence, the correlation between anthocyanin content and DEG expression levels was explored. Two structural genes (DFR and ANS), three GSTs (homologous to TT19), and 68 differentially expressed transcription factors (TFs), especially MYB-related TFs and WRKY44, were identified in three B. napus varieties characterized by different leaf color, thereby indicating that these genes may contribute to anthocyanin biosynthesis, transport, or accumulation in B. napus leaves. The findings of study provide important insights that may contribute to gaining a better understanding of the transcriptional regulation of anthocyanin metabolism in B. napus.

The Role of Ipomoea batatas Leaves Extract as a Potent Antioxidant and Anti-inflammatory in Rats Fed High-fat Diet

Ipomoea batatas L purple variant is a natural source of bioactive compounds with strong antioxidant activity and has long been used in folk medicine. This study aimed to evaluate the active compounds, antioxidant, and anti-inflammatory activities of Ipomoea batatas L purple variant leaf extract in rats fed a high-fat diet. The presence of active compounds in the Ipomoea batatas L purple variant was determined by liquid chromatography high resolution mass spectrometry (LC-HRMS). The rats were divided into five experimental groups of six animals in each group. Namely standard diet/normal group (SD), high-fat diet group (HFD), and HFD plus extracts (625; 1250; or 2500 mg/kg) groups for twelve weeks. The effect of leaf extract on antioxidant activity was analyzed using the DPPH assay, while oxidative stress and anti-inflammatory analysis were performed by immunohistochemistry. LC-HRMS analysis showed six active compounds were identified from Ipomoea batatas L. Besides, there is a reduction in oxidative stress through malondialdehyde (MDA) expression on the oral supplementation with Ipomoea batatas leaf purple variant extract doses of 1250 and 2500 mg/kg body weight. Meanwhile, all extract doses can significantly increase antioxidant activities such as nuclear factor-erythroid 2 related factor 2 (Nrf-2) expression, superoxide dismutase 2 (SOD2) expression, and decrease pro-inflammatory such as tumor necrosis factor alpha (TNF-α) expression in the aorta. Taken together, these findings provide a basis for the recommendation of compounds from the supplementation of an Ipomoea batatas L purple variant leaf extract can be an alternative herbal therapy to inhibit the harmful effects of a high-fat diet.

Transcriptome and Metabolome Profiling to Explore the Causes of Purple Leaves Formation in Non-Heading Chinese Cabbage (Brassica rapa L. ssp. chinensis Makino var. mutliceps Hort.).

Purple non-heading Chinese cabbage is one of the most popular vegetables, and is rich in various health-beneficial anthocyanins. Research related to genes associated with anthocyanin biosynthesis in non-heading Chinese cabbage is important. This study performed integrative transcriptome and metabolome analysis in the purple non-heading Chinese cabbage wild type (WT) and its green mutant to elucidate the formation of purple leaves. The anthocyanin level was higher in purple than in green plants, while the contents of chlorophyll and carotenoid were higher in the green mutant than in the purple WT. Twenty-five anthocyanins were identified in purple and green cultivars; eleven anthocyanin metabolites were identified specifically in the purple plants. RNA-seq analysis indicated that 27 anthocyanin biosynthetic genes and 83 transcription factors were significantly differentially expressed between the WT and its mutant, most of them with higher expression in the purple than green non-heading Chinese cabbage. Transcriptome and metabolome analyses showed that UGT75C1 catalyzing the formation of pelargonidin-3,5-O-diglucoside and cyanidin-3,5-O-diglucoside may play a critical role in purple leaf formation in non-heading Chinese cabbage. Therefore, these results provide crucial information for elucidating the formation of purple leaves in non-heading Chinese cabbage.

Regulation of flavonoid synthesis by &amp;lt;italic&amp;gt;BjA09.TT8 &amp;lt;/italic&amp;gt;and &amp;lt;italic&amp;gt;BjB08.TT8&amp;lt;/italic&amp;gt; genes in &amp;lt;italic&amp;gt;Brassica juncea&amp;lt;/italic&amp;gt;

<p id="C3">bHLH transcription factors TT8 can effectively regulate the biosynthesis of plant flavonoids. In this study, two copies of <italic>TT8 </italic>were obtained in <italic>Brassica juncea</italic> by homologous cloning method, and named <italic>BjA09.TT8</italic> and <italic>BjB08.TT8</italic>, which encoded 521 and 517 amino acids, respectively. Interestedly, qRT-PCR showed that the relative expression levels of the two copies in leaves were significantly higher than those in stems and roots, both responded to jasmonic acid (JA) signal, and the relative expression levels of <italic>Bju.TT8</italic> reached maximum after 50 µmol L^-1methyl jasmonate treatment for 0.5 hour. Furthermore, we found that both <italic>Bj.TT8</italic> can increase the contents of total flavonoids in hairy roots of purple leaf mustard and green leaf mustard cultiver Sichuan Yellow Seed by hairy root system overexpression assay. It promoted the expression of flavonoid synthesis<italic> Bj.CHS</italic>, indicating they acted as redundant function. Over expression of <italic>BjA09.TT8 </italic>and <italic>BjB08.TT8 </italic>of wild-type <italic>Arabidopsis</italic> and <italic>Arabidopsis tt8</italic> mutant revealed that the leaf colour of overexpressed <italic>Arabidopsis</italic> plant turned purple. Moreover, the contents of total flavonoid and proanthocyanidins increased significantly. In summary, <italic>BjA09.TT8 </italic>and <italic>BjB08.TT8</italic> genes could promote the synthesis of flavonoids in<italic> Brassica juncea</italic>, which provided a reference for further analysis of the regulatory mechanism of proanthocyanidin synthesis in <italic>Brassica</italic>.

Integrated Transcriptomic and Metabolomic Analyses Reveal the Mechanisms Underlying Anthocyanin Coloration and Aroma Formation in Purple Fennel.

The color and aroma are the significant traits of vegetables and fruits, but the metabolic and molecular mechanisms underlying anthocyanin accumulation and aroma formation remain almost unknown in fennel (Anethum foeniculum L.), which is a crucial vegetable crop and grown widely for aromatic leaves and bulbs. Here, ten major anthocyanins identified and quantified by ultra-high performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) were mainly responsible for the coloration of purple fennel leaf. With the application of GC-MS, it was found that the reduced volatile phenylpropanoids including isoeugenol, trans-isoeugenol, and apiol chiefly account for the characteristic aroma changes of the purple fennel. Moreover, the characteristic anthocyanin coloration and aroma formation in purple fennel were systematically studied with the integrated transcriptomics and metabolomics. The critical genes associated with the biosynthesis and regulation of anthocyanins and volatile phenylpropanoids were isolated and studied carefully in transiently transfected tobacco cells and transgenic tomato plants. Together with the results of UHPLC-Q-Orbitrap HRMS, RT-qPCR, and yeast two hybrid (Y2H), it is proved that the metabolic flux redirection of phenylpropanoid pathway primarily regulated by a functional MYB-bHLH-WD40 complex consisting of AfTT8, AfMYB7, and AfTTG1 accounts for the characteristic anthocyanin coloration and aroma formation in purple fennel leaf. The systematic understanding of the anthocyanin accumulation and aroma formation will assist in the improvement of fennel resource utilization and breeding.

Phytochemistry and Biological Activities of &lt;i&gt;Curcuma aeruginosa&lt;/i&gt; (Roxb.)

Curcuma aeruginosa Roxb. is a stemless, aromatic rhizomatous plant, generally characterized by red corolla lobes, purple calyx, dark purple leaf sheath, purple-brown midrib, and greenish-blue rhizome. This species is usually blooming during the wet and rainy seasons, while the rhizome and leaves have an aromatic odor indicating the presence of volatile constituents. This plant has been used in many traditional medicines as a disinfectant, expectorant, and tonic, including treatment for the wound, diarrhea, dysmenorrhea, fever, coughs, and asthma. This paper aims to provide C. aeruginosa Roxb., summarized data regarding traditional uses, ethnopharmacology, phytochemistry, and pharmacological activities. From 1987 to 2021, about 34 phytochemicals have been isolated, and up to 223 compounds have been detected using Gas Chromatography-Mass Spectrometry. These metabolites differ from flavonoids, terpenoids, steroids, phenanthrenes, and so forth. Furthermore, various investigations demonstrated that the extracts and compounds obtained from the plant possess several pharmacological activities such as anticancer, antioxidant, antimicrobial, anti-dengue, immunostimulant, anthelmintic, anti-inflammatory, antiandrogenic, anti-nociceptive, and antipyretic, as well as uterine relaxant effect. Curcuma aeruginosa Roxb. is a promising medicinal herb and is usually used as oriental traditional medicine by local folks. Therefore, the result supports this plant as a potential source for therapeutic applications and drug development prospects.

Untargeted metabolomics and comparative flavonoid analysis reveal the nutritional aspects of pak choi

Pak choi is a leafy vegetable with high economic value. Despite its importance, the information related to its metabolomics profile has still not been well-understood. This study aimed to determine the leaf metabolite composition of seven pak choi. In total, 513 metabolites belonging to 24 separate metabolite groups were detected. Pak choi leaves were rich in organic acids, amino acids, and flavonoids. There were ninety-two flavonoid compounds detected in pak choi leaves. Multivariate analysis revealed a distinct variation in the metabolite and flavonoid profile of green and purple leaved varieties. The flavonoid accumulation was comparatively greater in green leaved than purple leaf cultivar. This work provides novel insights into pak choi metabolomics profile, the flavonoids in particular, thus, to assess the nutritional value of this vegetable for humans.

Antioxidant and Antihyperlipidemic Effect of Purple Sweet Potato Leaf Extract (Ipomoea batatas L.) and Red Yeast Rice Combination In Hypercholesterol Rats

Hyperlipidemia is a condition of lipid such as cholesterol and triglycerides in the blood are high, which is the cause of other diseases. This condition also causes an increase in free radicals resulting in oxidative stress. Purple sweet potato leaves and red yeast rice have been reported to have antihyperlipidemic and antioxidant activity in several studies. This study aimed to examine the effect of the combination of purple sweet potato leaves extract and red yeast rice on cholesterol and triglyceride levels as well as MDA levels and GPx activity on rats induced by a high-fat diet. Experimental animals were randomly divided into 6 groups of 5 mice each: group 1 being the normal group; group 2 positive control; group 3 negative control; group 4 purple sweet potato leaf extract 400 mg/kg BW; group 5 red yeast rice 40 mg/kg BW; group 6 combination of purple sweet potato leaf extract 360 mg/kg BW and red yeast rice 40 mg/kg BW. Rats were treated with high-fat feed for 28 days, on day 15-28 were given oral preparations. At the end of the study, all rats were blood drawn to measure cholesterol and triglyceride levels, then rats were sacrificed and the liver was taken to measure MDA and glutathione peroxidase levels. The administration of purple sweet potato leaf extract, red yeast rice, and their combination significantly (p&lt;0,05) reduced cholesterol, triglyceride, and MDA levels, and increased GPx activity, with the best effect in the combination group. This finding showed that the combination of purple sweet potato leaf extract and red yeast rice had antihyperlipidemic and antioxidant activity in hypercholesterol rats.

Comparative Analysis of Proanthocyanidin Metabolism and Genes Regulatory Network in Fresh Leaves of Two Different Ecotypes of Tetrastigma hemsleyanum.

Tetrastigma hemsleyanum Diels et Gilg is a rare and wild medicinal resource. Metabolites, especially secondary metabolites, have an important influence on T. hemsleyanum adaptability and its medicinal quality. The metabolite proanthocyanidin (PA) is a polyphenol compound widely distributed in land plants, which can be used as antioxidants and anticancer agents. Here, we discovered that three types of PA accumulated in large amounts in purple leaves (PL), but not in green leaves (RG), based on widely non-targeted metabolomics. In addition, we further found that catechins and their derivatives, which are the structural units of PA, are also enriched in PL. Afterwards, we screened and obtained five key genes, DNR1/2, ANS, ANR and LAR closely related to PA biosynthesis through transcriptome analysis and found they were all highly expressed in PL compared to RG. Therefore, observed the regulatory relationship between the main compounds and genes network, and the PA metabolism regulatory pathway was complicated, which may be different to other species.

Assessment of Genetic Variability in Onion against Purple Leaf Blotch Disease under Field Conditions and its Management

Assessment of Genetic Variability in Onion against Purple Leaf Blotch Disease under Field Conditions and its Management

Purple leaf basil plants express micronutrient deficiencies symptoms differently than green leaf basil plants

All living organisms need essential nutrient elements to survive and thrive. For plants, of the 14 essential nutrient elements, over half show deficiency symptoms that include chlorosis. However, this is for plants with green leaves. For purple leaf basil, there has been no reported research on how microelement deficiency is expressed, diagnosed and/or corrected. The purpose of this research was to visually and quantitatively identify micronutrient element deficiencies, specifically, iron (Fe), manganese (Mn) and zinc (Zn), in ‘Red Rubin’, a purple leaf basil. To do this, three cultivars of basil, Italian Large Leaf, a green leaf basil; Aromatto, a mottled purple and green leaf basil; and Red Rubin, a purple leaf basil, were grown for 13–16 weeks. The experiment design was a split-plot with four treatments and the three cultivars. Data included visual observations, relative greenness (SPAD) measurements and tissue nutrient analysis. ‘Red Rubin’ leaves had similar SPAD values to both of the other cultivars. When Fe, Mn or Zn was deficient, purple pigment was lost. However, visual deficiencies such as yellowing and an increase in green color either veinally, interveinally or on the leaf margins varied. Based upon overlapping symptoms and based on tissue analysis, it is possible that there exists a 3-way or even 4-way interaction/balance among the minor elements Fe, Mn, Zn and possibly copper (Cu).

Germplasm Screening of Green Manure Rapeseed through the Effects of Short-Term Decomposition on Soil Nutrients and Microorganisms

The rapidly emerging fertilizer rapeseed used as green manure has wide applications for use. However, there have been few studies on its decomposition and effects on soil nutrients and microorganisms after its decay. In this study, 12 rapeseed lines to be screened were decomposed through a randomized block field design with two green-manure-specific varieties as the controls. The contents of nitrogen, phosphorus, and potassium from the plants, soil nutrients, and microbial changes after degradation were measured. There were substantial differences in the rates of decomposition and cumulative release of nutrients among the different lines after 30 days of rolling. The contents of phosphorus and potassium in the soil were 1.23–2.03 and 3.93–6.32 times those before decomposition, respectively. In addition, there was a significant difference in the relative content of soil microorganisms at the phylum level after the decomposition of different species of rapeseeds. Most of the top 20 bacterial groups significantly correlated with the characteristics of plant decomposition and soil nutrient content, including Proteobacteria, Actinomycetes, Armatimonadetes, Rokubacteria, and Planctomycetes. A principal component analysis showed that the soil microorganisms and nutrients are the leading factors that enable the evaluation of the decomposing characteristics of green manure rapeseed. Numbers 5 (purple leaf mustard) and 8 (Xiafang self-seeding) were more effective than two controls, which can be used as excellent types of germplasm to promote the breeding of green manure rapeseed.