scholarly journals Dark/Light Treatments Followed by γ-Irradiation Increase the Frequency of Leaf-Color Mutants in Cymbidium

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 532 ◽  
Author(s):  
Sang Hoon Kim ◽  
Se Won Kim ◽  
Jaihyunk Ryu ◽  
Si-Yong Kang ◽  
Byoung-Cheorl Kang ◽  
...  
Keyword(s):  
Chlorophyll Biosynthesis ◽  
Flower Color ◽  
Light Treatment ◽  
Leaf Color ◽  
Γ Irradiation ◽  
Dark Light ◽  
Chlorophyll Metabolism ◽  
Anthocyanin Pathway ◽  
Pathway Gene ◽  
Radiation Treatments

Radiation randomly induces chromosomal mutations in plants. However, it was recently found that the frequency of flower-color mutants could be specifically increased by upregulating anthocyanin pathway gene expression before radiation treatments. The mechanisms of chlorophyll biosynthesis and degradation are active areas of plant study because chlorophyll metabolism is closely connected to photosynthesis. In this study, we determined the dark/light treatment conditions that resulted in upregulation of the expression levels of six chlorophyll pathway genes, uroporphyrinogen III synthase (HEMD), uroporphyrinogen III decarboxylase (HEME2), NADPH-protochlorophyllide oxidoreductase (POR) A (PORA), chlorophyll synthase (CHLG), chlorophyllase (CLH2), and red chlorophyll catabolite reductase (RCCR), and measured their effects on the γ-irradiation-induced frequencies of leaf-color mutants in two Cymbidium cultivars. To degrade chlorophyll in rhizomes, 60–75 days of dark treatment were required. To upregulate the expressions of chlorophyll pathway genes, 10 days of light treatment appeared to be optimal. Dark/light treatments followed by γ-irradiation increased chlorophyll-related leaf mutants by 1.4- to 2.0-fold compared with γ-ray treatment alone. Dark/light treatments combined with γ-irradiation increased the frequency of leaf-color mutants in Cymbidium, which supports the wider implementation of a plant breeding methodology that increases the mutation frequency of a target trait by controlling the expression of target trait-related genes.

Integrated analyses of rice dark response and leaf color regulation reveal links with porphyrin and chlorophyll metabolism

2020 ◽  
Author(s):  
Tianxingzi Wang ◽  
Yue Chen ◽  
Zheng Zhu ◽  
Yuqing Liu ◽  
Gaowei Yan ◽  
...  
Keyword(s):  
Stress Response ◽  
Chlorophyll Biosynthesis ◽  
Light Signal ◽  
Integrated Analysis ◽  
Rna Seq ◽  
Leaf Color ◽  
Chlorophyll Metabolism ◽  
Leaf Yellowing ◽  
Dark Stress ◽  
Color Regulation

Abstract Background Light is a key regulatory signal for rice growth and development. Under dark stress, rice shows leaf yellowing. Whole genome transcriptomic analysis will identify differentially expressed genes (DEG) in dark-treated rice seedlings and DEG-enriched metabolic pathways. Rice leaf color is an essential agronomic trait. Traditional genetic experiments have reported over a hundred of leaf color-related (LCR) genes and some of them were also regulated by light signal. Thus, an integrated analysis for the two set of data will be helpful for illustration of the mechanism for both dark-response and leaf color regulation. Results Transcriptome changes in response to dark treatment were surveyed by RNA-Seq analysis. About 13,115 DEGs were identified. One hundred and fifty rice LCR genes were collected. It was found that 102 LCR genes (68.0%) were also dark-response DEGs, which suggests an overlap between dark response and LCR networks. Fifty DEG overlapped LCR genes was associated with chloroplast development. KEGG analysis revealed enrichment of LCR genes in porphyrin and chlorophyll metabolism (PCM) (18/44, 40.9%). Of the 18 LCR genes in the PCM pathway, 15 were dark-response DEGs (83.3%). More interestingly, most of them are involved in a central PCM sub-pathway, chlorophyll biosynthesis. Conclusions Integrated analysis for dark stress-response and leaf color regulation identified the correlation between the two processes and mutually supported evidences were obtained. It was found that PCM pathway, particularly chlorophyll biosynthesis process, is a core component of the overlap and plays important roles in rice LCR and dark stress-response. This study provides important clues for identifying additional LCR genes, understanding the mechanisms of dark response and leaf color regulation.

scholarly journals Integrated analyses of rice dark response and leaf color control reveal links with porphyrin and chlorophyll metabolism

2020 ◽  
Author(s):  
Tianxingzi Wang ◽  
Yue Chen ◽  
Zheng Zhu ◽  
Yuqing Liu ◽  
Gaowei Yan ◽  
...  
Keyword(s):  
Stress Response ◽  
Differentially Expressed Genes ◽  
Chlorophyll Biosynthesis ◽  
Light Signal ◽  
Differentially Expressed ◽  
Integrated Analysis ◽  
Leaf Color ◽  
Chlorophyll Metabolism ◽  
Color Control ◽  
Dark Stress

Abstract Background: Light is a key regulatory signal for rice growth and development. Under dark stress, rice shows leaf yellowing. Whole genome transcriptomic analysis will identify differentially expressed genes (DEG) in dark-treated rice seedlings and DEG-enriched metabolic pathways. Rice leaf color is an essential agronomic trait. Traditional genetic experiments have reported over a hundred of leaf color control (LCC) genes and some of them were also regulated by light signal. Thus, an integrated analysis for the two set of data will be helpful for illustration of the mechanism for both dark-response and leaf color control.Results: Transcriptome changes in response to dark treatment were surveyed by RNA-Seq analysis. About 13,115 differentially expressed genes (DEGs) were identified. One hundred and fifty rice LCC genes were collected. It was found that 102 LCC genes (68.0%) were also dark-response DEGs, which suggests an overlap between dark response and LCC networks. Fifty DEG overlapped LCC genes was associated with chloroplast development. KEGG analysis revealed enrichment of LCC genes in porphyrin and chlorophyll metabolism (PCM) (18/44, 40.9%). Of the 18 LCC genes in the PCM pathway, 15 were dark-response DEGs (83.3%). More interestingly, all of them are involved in a central PCM sub-pathway, chlorophyll biosynthesis.Conclusions: Integrated analysis for dark stress-response and leaf color control identified the correlation between the two processes and mutually supported evidences were obtained. It was found that PCM pathway, particularly chlorophyll biosynthesis process, plays important roles in rice LCC and dark stress-response. This study provides important clues for understanding the mechanisms of dark response and leaf color control and identifying additional LCC genes.

scholarly journals Identification of two recessive etiolation genes (py1, py2) in pakchoi (Brassica rapa L. ssp. chinensis)

2020 ◽  
Author(s):  
Kun Zhang ◽  
Yu Mu ◽  
Weijia Li ◽  
Xiaofei Shan ◽  
Nan Wang ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Crop Yields ◽  
Microspore Culture ◽  
Chlorophyll Biosynthesis ◽  
Differentially Expressed Gene ◽  
Nuclear Genes ◽  
Single Amino Acid ◽  
Leaf Color ◽  
Chlorophyll Metabolism ◽  
Metabolism Regulation

Abstract Background: Leaf color is a major agronomic trait, which has a strong influence on crop yields. Isolating leaf color mutants can represent valuable materials for research in chlorophyll biosynthesis and metabolism regulation.Results: In this study, we identified a stably inherited yellow leaf mutant derived from ‘Huaguan’ pakchoi variety via isolated microspore culture and designated as pylm. This mutant displayed yellow leaves after germination. Its etiolated phenotype was nonlethal and stable during the whole growth period. Its growth was weak and its hypocotyls were markedly elongated. Genetic analysis revealed that two recessive nuclear genes, named py1 and py2, are responsible for the etiolation phenotype. Bulked segregant RNA sequencing (BSR-Seq) showed that py1 and py2 were mapped on chromosomes A09 and A07, respectively. The genes were single Mendelian factors in F3:4 populations based on a 3:1 phenotypic segregation ratio. The py1 was localized to a 258.3-kb interval on a 34-gene genome. The differentially expressed gene BraA09004189 was detected in the py1 mapping region and regulated heme catabolism. One single-nucleotide polymorphism (SNP) of BraA09004189 occurred in pylm. A candidate gene-specific SNP marker in 1,520 F3:4 yellow-colored individuals co-segregated with py1. For py2, 1,860 recessive homozygous F3:4 individuals were investigated and localized py2 to a 4.4-kb interval. Of the five genes in this region, BraA07001774 was predicted as a candidate for py2. It encoded an embryo defective 1187 and a phosphotransferase related to chlorophyll deficiency and hypocotyl elongation. One SNP of BraA07001774 occurred in pylm. It caused a single amino acid mutation from Asp to Asn. According to quantitative real-time polymerase chain reaction (qRT-PCR), BraA07001774 was downregulated in pylm. Conclusions: Our study identified a Chl deficiency mutant pylm in pakchoi. Two recessive nuclear genes named py1 and py2 had a significant effect on etiolation. Candidate genes regulating etiolation were identified as BraA09004189 and BraA07001774, respectively. These findings will elucidate chlorophyll metabolism and the molecular mechanisms of the gene interactions controlling pakchoi etiolation.

scholarly journals CmNAC73 Mediates the Formation of Green Color in Chrysanthemum Flowers by Directly Activating the Expression of Chlorophyll Biosynthesis Genes HEMA1 and CRD1

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 704
Author(s):  
Jing Luo ◽  
Huan Wang ◽  
Sijia Chen ◽  
Shengjing Ren ◽  
Hansen Fu ◽  
...  
Keyword(s):  
Chlorophyll Biosynthesis ◽  
Flower Color ◽  
Chlorophyll Synthesis ◽  
Chrysanthemum Morifolium ◽  
Gene Encoding ◽  
Chlorophyll Metabolism ◽  
Chlorophyll Accumulation ◽  
Transient Overexpression ◽  
Highly Correlated ◽  
Dark Green

Chrysanthemum is one of the most beautiful and popular flowers in the world, and the flower color is an important ornamental trait of chrysanthemum. Compared with other flower colors, green flowers are relatively rare. The formation of green flower color is attributed to the accumulation of chlorophyll; however, the regulatory mechanism of chlorophyll metabolism in chrysanthemum with green flowers remains largely unknown. In this study, we performed Illumina RNA sequencing on three chrysanthemum materials, Chrysanthemum vestitum and Chrysanthemum morifolium cultivars ‘Chunxiao’ and ‘Green anna,’ which produce white, light green and dark green flowers, respectively. Based on the results of comparative transcriptome analysis, a gene encoding a novel NAC family transcription factor, CmNAC73, was found to be highly correlated to chlorophyll accumulation in the outer whorl of ray florets in chrysanthemum. The results of transient overexpression in chrysanthemum leaves showed that CmNAC73 acts as a positive regulator of chlorophyll biosynthesis. Furthermore, transactivation and yeast one-hybrid assays indicated that CmNAC73 directly binds to the promoters of chlorophyll synthesis-related genes HEMA1 and CRD1. Thus, this study uncovers the transcriptional regulation of chlorophyll synthesis-related genes HEMA1 and CRD1 by CmNAC73 and provides new insights into the development of green flower color in chrysanthemum and chlorophyll metabolism in plants.

scholarly journals Effect of chlorophyll biosynthesis-related genes on the leaf color in Hosta (Hosta plantaginea Aschers) and tobacco (Nicotiana tabacum L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingying Zhang ◽  
Changhai Sui ◽  
Huimin Liu ◽  
Jinjiao Chen ◽  
Zhilin Han ◽  
...  
Keyword(s):  
Light Intensity ◽  
Antioxidant Capacity ◽  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Expression Level ◽  
Virus Induced Gene Silencing ◽  
Leaf Color ◽  
Color Changes ◽  
Light Intensities ◽  
Structure Changes

Abstract Background ‘Regal Splendour’ (Hosta variety) is famous for its multi-color leaves, which are useful resources for exploring chloroplast development and color changes. The expressions of chlorophyll biosynthesis-related genes (HrHEMA, HrPOR and HrCAO) in Hosta have been demonstrated to be associated with leaf color. Herein, we isolated, sequenced, and analyzed HrHEMA, HrPOR and HrCAO genes. Subcellular localization was also performed to determine the location of the corresponding enzymes. After plasmid construction, virus-induced gene silencing (VIGS) was carried out to reduce the expressions of those genes. In addition, HrHEMA-, HrPOR- and HrCAO-overexpressing tobacco plants were made to verify the genes function. Changes of transgenic tobacco were recorded under 2000 lx, 6000 lx and 10,000 lx light intensity. Additionally, the contents of enzyme 5-aminolevulinic acid (5-ALA), porphobilinogen (PBG), chlorophyll a and b (Chla and Chlb), carotenoid (Cxc), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), proline (Pro) and catalase (CAT) under different light intensities were evaluated. Results The silencing of HrHEMA, HrPOR and HrCAO genes can induce leaf yellowing and chloroplast structure changes in Hosta. Specifically, leaves of Hosta with HrCAO silencing were the most affected, while those with HrPOR silencing were the least affected. Moreover, all three genes in tobacco were highly expressed, whereas no expression was detected in wild-type (WT). However, the sensitivities of the three genes to different light intensities were different. The highest expression level of HrHEMA and HrPOR was detected under 10,000 lx of illumination, while HrCAO showed the highest expression level under 6000 lx. Lastly, the 5-ALA, Chla, Cxc, SOD, POD, MDA, Pro and CAT contents in different transgenic tobaccos changed significantly under different light intensities. Conclusion The overexpression of these three genes in tobacco enhanced photosynthesis by accumulating chlorophyll content, but the influential level varied under different light intensities. Furthermore, HrHEMA-, HrPOR- and HrCAO- overexpressing in tobacco can enhance the antioxidant capacity of plants to cope with stress under higher light intensity. However, under lower light intensity, the antioxidant capacity was declined in HrHEMA-, HrPOR- and HrCAO- overexpressing tobaccos.

scholarly journals Computational modeling of anthocyanin pathway evolution

2019 ◽  
Author(s):  
Lucas C. Wheeler ◽  
Stacey D. Smith
Keyword(s):  
Metabolic Pathways ◽  
Flower Color ◽  
Complex Phenotype ◽  
Pathway Evolution ◽  
Anthocyanin Pathway ◽  
Trade Offs ◽  
Wide Range ◽  
Pathway Function ◽  
Simple Kinetic Model ◽  
New Mutations

AbstractAlteration of metabolic pathways is a key component of the evolution of new phenotypes. Flower color is a striking example of the importance of metabolic evolution in a complex phenotype, wherein shifts in the activity of the underlying pathway lead to a wide range of pigments. Although experimental work has identified common classes of mutations responsible for transitions among colors, we lack a unifying model that relates pathway function and activity to the evolution of distinct pigment phenotypes. One challenge in creating such a model is the branching structure of pigment pathways, which may lead to evolutionary trade-offs due to competition for shared substrates. In order to predict the effects of shifts in enzyme function and activity on pigment production, we created a simple kinetic model of a major plant pigmentaion pathway: the anthocyanin pathway. This model describes the production of the three classes of blue, purple and red anthocyanin pigments, and accordingly, includes multiple branches and substrate competition. We first studied the general behavior of this model using a realistic, functional set of parameters. We then stochastically evolved the pathway toward a defined optimum and and analyzed the patterns of fixed mutations. This approach allowed us to quantify the probability density of trajectories through pathway state space and identify the types and number of changes. Finally, we examine whether the observed trajectories and constraints help to explain experimental observations, i.e., the predominance of mutations which change color by altering the function of branching genes in the pathway. These analyses provide a theoretical framework which can be used to predict the consequences of new mutations in terms of both pigment phenotypes and pleiotropic effects.

scholarly journals Eksplorasi dan Karakterisasi Tanaman Genjer (Limnocharis flava (L.) Buch) di Kabupaten Pangandaran Berdasarkan Karakter Morfologi dan Agronomi

Jurnal Agro ◽  
10.15575/967 ◽  
2016 ◽  
Vol 3 (2) ◽  
pp. 53-66 ◽  
Author(s):  
Liberty Chaidir ◽  
Kristi Yuliani ◽  
Budy Frasetya Taufik Qurrohman
Keyword(s):  
Heavy Metals ◽  
Genetic Relationship ◽  
Euclidean Distance ◽  
Flower Color ◽  
Leaf Length ◽  
Agronomic Characters ◽  
Leaf Color ◽  
Purposive Sampling ◽  
Lowland Area ◽  
Relationship Of

Genjer merupakan tanaman yang tumbuh liar di area persawahan, rawa, atau sungai yang keberadaannya sering dianggap sebagai gulma. Tanaman genjer memiliki banyak manfaat, diantaranya sebagai bahan penyerap logam berat dalam tanah dan sebagai obat yang memiliki banyak kandungan gizi. Penelitian ini bertujuan untuk mengetahui variasi karakter morfologi dan karakter agronomi untuk mengetahui hubungan kekerabatan tanaman genjer antar daerah di Kabupaten Pangandaran. Penelitian dilaksanakan di Kabupaten Pangandaran pada Mei sampai Oktober 2015. Metode yang digunakan adalah metode eksplorasi purposive sampling pada 77 aksesi genjer yang diambil dari Kabupaten Pangandaran. Hasil penelitian menunjukkan terdapat keragaman fenotipik yang luas pada karakter morfologi ujung daun, warna batang, tekstur daun, warna daun, panjang lekukan bawah daun, warna kelopak bunga dan warna bunga. Karakter agronomi yang mempunyai keragaman yang luas ialah tinggi tanaman, jumlah batang per rumpun, panjang daun, lebar daun, jumlah daun, jumlah bunga dan diameter batang. Tanaman genjer di Kabupaten Pangandaran memiliki kekerabatan yang jauh dengan rentang jarak Euclidian 0,48 sampai 10,17. Aksesi yang memiliki hubungan kekerabatan paling jauh yaitu Ciakar (001) dengan jarak Euclidian 10,17, sedangkan yang memiliki hubungan kekerabatan paling dekat yaitu Cikalong (003) dan Cikalong (004) dengan jarak Euclidian 0,48. Genjer or Yellow velvetleaf is a plant that grows wild in lowland area, swamp or river which existence is considered as a weed. Genjer has a lot of benefits, such as material absorbent for heavy metals in the soil and medicine that has a lot of nutrition. This study aimed to determine the variety of morphological and agronomic characters of Genjer in Pangandaran Regency and to determine the genetic relationship of genjer between regions in Pangandaran. The research was conducted in the Pangandaran Regency on May to October 2015. The method used purposive sampling exploration method in 77 accession genjer collected from Pangandaran Regency. The results showed there were extensively phenotypic variation in tip of leaf, stem color, leaf texture, leaf color, length curve of bottom leaf, petal color and flower color. While agronomic characters for plant height, stem amount, leaf length, leaf width, leaf amount, flower amount and diameter of the stem had wide variation. Relationship between genjer in Pangandaran Regency had Euclidean distance with a range of 0.48 to 10.17. The accession which had the farthest distance was Ciakar (001) with Euclidean distance of 10.17, while those with the closest relationship were Cikalong (003) and Cikalong (004) with Euclidean distance of 0.48.

scholarly journals Comparative Transcriptome Analysis Revealed Two Alternative Splicing bHLHs Account for Flower Color Alteration in Chrysanthemum

2021 ◽  
Vol 22 (23) ◽  
pp. 12769
Author(s):  
Lili Xiang ◽  
Xiaofen Liu ◽  
Yanna Shi ◽  
Yajing Li ◽  
Weidong Li ◽  
...  
Keyword(s):  
Feedback Loop ◽  
Flower Color ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Anthocyanin Accumulation ◽  
Comparative Transcriptome ◽  
Moderate Amount ◽  
Anthocyanin Pathway ◽  
Color Alteration ◽  
Two Hybrid

‘Jimba’ is a white chrysanthemum cultivar, which occasionally and spontaneously produces red flower petals under natural cultivation due to cyanidin-based anthocyanin accumulation. To investigate the underlying mechanism of this process, a comparative transcriptome was analyzed between white and turning red ‘Jimba’. The structural and regulatory genes of anthocyanin pathway were significantly up-regulated in turning red ‘Jimba’. Among them, two alternative splicings, CmbHLH2 and CmbHLH2.1, showed the most significantly up-regulated in turning red tissue. Transiently over-expressed 35S::CmMYB6-CmbHLH2 strongly induced anthocyanin accumulation in ‘Jimba’ flower petals, while moderate amount of anthocyanin was detected when over-expressed 35S::CmMYB6-CmbHLH2.1. Both CmbHLH2 and CmbHLH2.1 could interact with CmMYB6 to activate CmDFR promoter according to Yeast two-hybrid and dual-luciferase assay. Moreover, CmMYB6-CmbHLH2 but not CmMYB6-CmbHLH2.1 could activate the CmbHLH2 promoter to provide positive feedback loop regulation. Taken together, it suggested that both CmbHLH2 and CmbHLH2.1 involved in regulation flower color alteration in turning red ‘Jimba’, and CmbHLH2 played a predominant role in this process.

scholarly journals Comparative transcriptome analyses reveal genes related to pigmentation in the petals of a flower color variation cultivar of Rhododendron obtusum

2021 ◽  
Author(s):  
Xiaobo Sun ◽  
Lisi He ◽  
Zhenhao Guo ◽  
Jiale Su ◽  
Xiaoqing Liu ◽  
...  
Keyword(s):  
Flower Color ◽  
Development Stage ◽  
Color Variation ◽  
Strongly Correlated ◽  
Anthocyanin Pathway ◽  
Phenylpropanoid Biosynthesis ◽  
Genetic Mechanisms ◽  
Research Goal ◽  
Woody Ornamental Plant ◽  
R2r3 Myb

Abstract Rhododendron is an important woody ornamental plant and breeding varieties with different colors is vital research goal. In this study, a flower color variation cultivar ‘Yanzhi Mi’ (pink petals) and the wild-type (WT) cultivar ‘Dayuanyangjin’ (white petals with pink stripes) were used as research objects, the pigment and transcriptome of their petals during different flower development (stage S1, S2, S3, S4 and S5) were analyzed and compared. The results showed that the derivatives of cyanidin, peonidin and pelargonidin may be responsible for the pink of mutant petals and S2 stage (buds showing color at the top but with the scales still present) was the key stage of flower color formation of mutant. In total, 412,910 transcripts and 2,780 differentially expressed genes (DEGs) were identified in pairwise comparisons of WT and mutant petals. GO and KEGG enrichment analyses of the DEGs showed that the ‘DNA-binding transcription factor activity’, ‘Flavonoid biosynthesis’ and ‘Phenylpropanoid biosynthesis’ were more active in mutant petals. Early anthocyanin pathway candidate DEGs (CHS3-CHS6, CHI, F3Hs and F3’H) were strongly correlated and up-regulated expression in mutant petals than in WT petals at S2 stage. These genes may be the key structural genes for the pink coloration of mutant petals. In the petals of mutant, two R2R3-MYB unigene (TRINITY_DN59015_c3_g2 and TRINITY_DN49281_c1_g6) were identified as repressors involved in anthocyanin regulation and were significantly down-regulated at S2 stage. This study shed light on the biochemistry and genetic mechanisms underlying the flower coloration in two Rhododendron obtusum cultivars.

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