Color Mutants Research Articles

Homological Series in the Variability of the Coat Color in Fur Animals

Phenotypic parallelism has been established with similar aberrations of coat color in sables and northern fur seals with known fur color mutations in American mink. On the basis of the similarities in the phenotypic variability of the coat color in these species of distant origin, we can imply the presence of specific coloring markers of the gene component, which ensures adaptation to extreme environmental conditions.

GraS is critical for chloroplast development and affects yield in rice

Leaf color has been considered an important agronomic trait in rice ( Oryza sativa L.) for a long time. The changes in leaf color affect the yield of rice. In this study, a green-revertible albino ( graS ) mutant was isolated from a 60 Co-gamma-irradiated mutant pool of indica cultivar Guangzhan 63-4S. The fine mapping indicated that graS mutant was mapped to chromosome 1, and was located in a confined region between markers ab134 and InDel 8 with genetic distances of 0.11 and 0.06 cM, respectively. Based on the annotation results, four open reading frames (ORFs) were predicted in this region. Sequence analysis revealed that LOC_Os01g55974 had a 2-bp nucleotide insertion (AA) in the coding region that led to premature termination at the 324th base. Sequence analysis and expression analysis of related genes indicated that LOC_Os01g55974 is the candidate gene of GraS. We studied the genome and protein sequences of LOC_Os01g55974, and the data showed that GraS contains a deoxycytidine deaminase domain, which was expressed ubiquitously in all tissues. Further investigation indicated that GraS plays an essential role in the regulation of chloroplast biosynthesis, photosynthetic capacity and yield. Moreover, leaf color mutant can be used as an effective marker for the purity of breeding and hybridization.

Carotenoid metabolite and transcriptome dynamics underlying flower color in marigold (Tagetes erecta L.)

Marigold (Tagetes erecta L.) is an important ornamental plant with a wide variety of flower colors. Despite its economic value, few biochemical and molecular studies have explored the generation of flower color in this species. To study the mechanism underlying marigold petal color, we performed a metabolite analysis and de novo cDNA sequencing on the inbred line ‘V-01’ and its petal color mutant ‘V-01M’ at four flower developmental stages. A total of 49,217 unigenes were identified from 24 cDNA libraries. Based on our metabolites and transcriptomic analyses, we present an overview of carotenoid biosynthesis, degradation, and accumulation in marigold flowers. The carotenoid content of the yellow mutant ‘V-01M’ was higher than that of the orange inbred line ‘V-01’, and the abundances of the yellow compounds lutein, neoxanthin, violaxanthin, zeaxanthin, and antheraxanthin were significantly higher in the mutant. During flower development, the carotenoid biosynthesis genes were upregulated in both ‘V-01’ and ‘V-01M’, with no significant differences between the two lines. By contrast, the carotenoid degradation genes were dramatically downregulated in the yellow mutant ‘V-01M’. We therefore speculate that the carotenoid degradation genes are the key factors regulating the carotenoid content of marigold flowers. Our research provides a large amount of transcriptomic data and insights into the marigold color metabolome.

Induction of Petal Color Mutants through Gamma Ray Irradiation of Spray Rose Cultivar‘Haesal’

This study was conducted to investigate the variation aspects and the growth characteristics of major color mutants after the treatment of gamma rays on cuttings and rooted cuttings in order to develop useful color variation of spray rose ‘Haesal’ with excellent taste of producers and markets in a short period of time. The higher the dose, the higher the plant mortality rate, and the decrease in the amount of shoots and shoot growth, regardless of the gamma-ray treatment sample type. The 50% lethal dose with the cutting (LD50, 50% lethal dose) was from 70 Gy and the rooted cutting was from 90 Gy, and the mutation rate was 2.6% and 3.1% in the cutting and rooted cutting, respectively. The variations were solid, chimera, and flower morphology, and these patterns were the same for both the cutting and rooting cutting. The color mutant of MUL-1 and MUL- 2, w hich are a lmost similar to s pray r ose cultivar ‘Haesal’, were induced at 70 Gy and 50 Gy dose from the gamma-ray irradiation, as a result of the investigation of the characteristics, flower diameter, petal number and cut flower yield were slightly less than spray rose cultivar ‘Haesal’, but the flower type, leaves and cut flower length were not different from the ‘Haesal’.

Fine Mapping and Transcriptome Analysis of Virescent Leaf Gene v-2 in Cucumber (Cucumis sativus L.).

Leaf color mutants are the ideal materials to explore the pathways of chlorophyll metabolism, chloroplast development and photosynthesis system. In this study, a new virescent leaf mutant 104Y was identified by spontaneous mutation, whose cotyledon and upper five true leaves were yellow color. The yellow true leaves gradually turned green from top to bottom with increased chlorophyll contents. Genetic analysis indicated that the virescent leaf was controlled by one single recessive gene v-2, which was accurately mapped into 36.0–39.7 Mb interval on chromosome 3 by using BSA-seq and linkage analysis. Fine mapping analysis further narrowed v-2 into 73-kb genomic region including eight genes with BC1 and F2 populations. Through BSA-seq and cDNA sequencing analysis, only one nonsynonymous mutation existed in the Csa3G890020 gene encoding auxin F-box protein was identified, which was predicted as the candidate gene controlling virescent leaf. Comparative transcriptome analysis and quantitative real-time PCR analysis revealed that the expression level of Csa3G890020 was not changed between EC1 and 104Y. However, RNA-seq analysis identified that the key genes involved in chlorophyll biosynthesis and auxin signaling transduction network were mainly down-regulated in 104Y compared with EC1, which indicated that the regulatory functions of Csa3G890020 could be performed at post-transcriptional level rather than transcriptional level. This is the first report to map-based clone an auxin F-box protein gene related to virescent leaf in cucumber. The results will exhibit a new insight into the chlorophyll biosynthesis regulated by auxin signaling transduction network.

Metabolome and transcriptome analyses of the molecular mechanisms of flower color mutation in tobacco

BackgroundAnthocyanins determinate the flower color of many plants. Tobacco is a model plant for studying the molecular regulation of flower coloration. We investigated the mechanism underlying flower coloration in tobacco by profiling flavonoid metabolites,expression of anthocyanin biosynthetic structural genes and their regulator genes in the pink-flowered tobacco cultivar Yunyan 87 and white-flowered Yunyan 87 mutant.ResultSignificant down-accumulation of anthocyanins, including cyanidin 3-O-glucoside, cyanin, cyanidin 3-O-rutinoside, pelargonidin 3-O-beta-D-glucoside, cyanidin O-syringic acid, pelargonin, and pelargonidin 3-O-malonylhexoside (log2 fold change < − 10), endowed the flower color mutation in Yunyan 87 mutant. Transcriptome analysis showed that the coordinately down-regulated anthocyanin biosynthetic genes including chalcone isomerase, naringenin 3-dioxygenase, dihydroflavonol 4-reductase and UDP-glucose:flavonoid 3-O-glucosyltransferase played critical roles in suppressing the formation of the aforesaid anthocyanins. Several genes encoding MYB and bHLH transcription factors were also found down-regulated, and probably the reason for the suppression of structural genes.ConclusionThis is the first study of tobacco flower coloration combining metabolome and transcriptome analyses, and the results shed a light on the systematic regulation mechanisms of flower coloration in tobacco. The obtained information will aid in developing strategies to modify flower color through genetic transformation.

Mutation Mechanism of Leaf Color in Plants: A Review

Color mutation is a common, easily identifiable phenomenon in higher plants. Color mutations usually affect the photosynthetic efficiency of plants, resulting in poor growth and economic losses. Therefore, leaf color mutants have been unwittingly eliminated in recent years. Recently, however, with the development of society, the application of leaf color mutants has become increasingly widespread. Leaf color mutants are ideal materials for studying pigment metabolism, chloroplast development and differentiation, photosynthesis and other pathways that could also provide important information for improving varietal selection. In this review, we summarize the research on leaf color mutants, such as the functions and mechanisms of leaf color mutant-related genes, which affect chlorophyll synthesis, chlorophyll degradation, chloroplast development and anthocyanin metabolism. We also summarize two common methods for mapping and cloning related leaf color mutation genes using Map-based cloning and RNA-seq, and we discuss the existing problems and propose future research directions for leaf color mutants, which provide a reference for the study and application of leaf color mutants in the future.

Codominant inheritance of polymorphic color mutant and characterization of a bisexual mutant of Gracilaria caudata (Gracilariales, Rhodophyta)

The red alga Gracilaria caudata is one of the main agarophytes exploited on the Brazilian coast. A greenish-brown mutant was found growing side-by-side with the common red wild type in a natural population. In this work, we tested the hypotheses that the greenish-brown phenotype has a recessive nuclear inheritance and less fitness (growth, photosynthesis, number of apices, secondary attachment percentage, and number of cystocarps) under laboratory conditions when compared with the red phenotype. Crosses between plants of the same color (red or greenish-brown) showed tetrasporophytic and subsequent gametophytic generations with parental phenotype. However, heterozygous tetrasporophytes, obtained from crosses between plants with different colors, showed a brown phenotype. From their progeny, we concluded that the brown phenotype is due to a monolocus Mendelian genetic system with two codominant alleles. Bisexual gametophytes were found in the progeny of tetrasporophytic color mutants, which is an unusual and poorly known characteristic in the life cycle of Gracilariales. Red female gametophytes (rd genotype) presented better performance in relation to the greenish-brown female gametophytes (gb genotype): growth rates (rd = 17.14 ± 1.36, gb = 13.81 ± 0.95); number of apices (rd = 41.05 ± 6.35, gb = 16.00 ± 5.47); secondary attachment percentage (rd = 68.75 ± 23.93, gb = 25 ± 0.00); and number of cystocarps (rd = 38.61, gb = 18.81). Our results explain the maintenance of the greenish-brown mutant and the predominance of red specimens in natural population. The life cycle was completed in 5 months, one of the shortest times reported for Gracilaria, highlighting the importance of the species as a possible model organism for reproductive studies and in selecting strains for use in mariculture.

Flower color mutation caused by spontaneous cell layer displacement in carnation (Dianthus caryophyllus)

A change of layer arrangement of shoot apical meristem (SAM) organized by three cell layers (L1, L2 and L3) is thought to be one of the provocations of bud sport, which often induces changes in phenotypic colors in periclinal chimeras. This paper describes a cell layer rearrangement which is the cause of spontaneous flower color mutation by using two carnation (Dianthus caryophyllus L.) cultivars that are presumably periclinal chimeras, 'Feminine Minami' (deep pink flower) and its recessive sport 'Tommy Minami' (pinkish red flower). The genotype of the acyl-glucose-dependent anthocyanin 5-glucosyltransferase (AA5GT) which is responsible for the color change of red to pink, in each cell layer was deduced by genomic analysis using tissues originated from specific cell layer and investigation of partial petal color mutations. In the results, the genotype of the L1 of 'Feminine Minami' was heterozygous for functional AA5GT and non-functional AA5GT carrying retrotransposon Ty1dic1 (AA5GT-Ty1dic1), and its inner cell layer hid red flower genotype, whereas AA5GT-Ty1dic1 of the L1 of 'Tommy Minami' became homogenic in absence of the insertion of a new Ty1dic1. Our outcomes concluded that the L1 of 'Tommy Minami' harboring the recessive AA5GT alleles are attributed to the inner cell layer of 'Feminine Minami' possessing red flower genotype.

Mutations in cardinal are responsible for the red-1 and peach eye color mutants of the red flour beetle Tribolium castaneum

Ommochromes are the major pigments found in the eyes, eggs, wings and epidermis of insects. Here, we report the identification and characterization of the gene responsible for red-1 locus of Tribolium, whose mutants have white eyes due to lack of ommochrome pigments in the eyes. Using a candidate gene approach, we demonstrated that red-1 and peach mutants have molecular defects in the cardinal gene, which encodes a haem peroxidase that is considered to convert 3-hydroxykynurenine into ommochromes in pigment granules. Our experiments showed that the expression pattern of cardinal correlates well with the progression of eye pigmentation during pupal stages. We performed gene editing experiments using the Receptor-Mediated Ovary Transduction of Cargo (ReMOT) Control technique to disrupt the cardinal gene by adult injection, and were able to establish a novel cardinal mutant line. Our complementation test provided definitive genetic evidence that cardinal is located at the red-1 locus. The present study will lead to a greater understanding of the function and diversity of ommochrome pathway genes in insects. Our successful use of ReMOT Control in beetles will facilitate the development of more efficient and versatile systems for insect genome editing by simple adult injection.

The assessment of epigenetic diversity, differentiation, and structure in the 'Fuji' mutation line implicates roles of epigenetic modification in the occurrence of different mutant groups as well as spontaneous mutants.

The ‘Fuji’ line includes many varieties with a similar genetic background and consistent inducement factors with epigenetic occurrence, thus it may be considered an ideal candidate for epigenetic research. In this study, 91 bud mutations of ‘Fuji’ apple were used as the test materials. Using the genetic variation within ‘Fuji’ as the control, the characteristics of epigenetic variation at different levels in both varieties and mutant groups were examined. The results showed that: (1) the global genomic DNA methylation level of the 91 bud mutants of ‘Fuji’ ranged from 29.120%-45.084%, with an average of 35.910%. Internal cytosine methylation was the main DNA methylation pattern. Regarding the variation of methylation patterns of ‘Fuji’ mutants, the vast majority of loci maintained the original methylation pattern existed in ‘Fuji’. CHG methylation variation was the main type of variation; (2) the variation in methylation patterns between the mutant groups was greater than that of methylation levels. Among these patterns, the variation in CHG methylation patterns (including CHG hypermethylation and CHG demethylation) was expected to be dominant. The observed variation in methylation levels was more important in the Color mutant group; however, the variation in methylation patterns was more obvious in both the early maturation and Spur mutant groups. Moreover, the range of variation in the Early-maturation group was much wider than that in the Spur mutant group; (3) epigenetic diversity and genetic diversity were both low between the mutant groups. In the ‘Fuji’ mutant groups, there was few correlation between genetic and epigenetic variation, and epigenetic differentiation resulted in more loci with moderate or greater differentiation; (4) the purifying selection seemed to play a major role in the differentiation of different groups of ‘Fuji’ mutants (65.618%), but epigenetic diversity selection still occurred at nearly 35% of loci. Sixteen epigenetic outlier loci were detected.

Characterization and fine mapping of a leaf yellowing mutant in common wheat

Creation of leaf color mutants is the options in the study of photosynthesis, chloroplast development and Chlorophyll biosynthesis. In this study, a leaf color mutant NAU31 was identified from tissue culture of common wheat. In general, the mutant exhibited whole plant yellowing, fewer tillering, dwarfing and interestingly, improved resistance to wheat powdery mildew. Photosynthetic physiological analysis showed that the chloroplast inner structure varied in the mesophyll cells of the mutant, and this may lead to reduced chlorophyll content (chlorophyll “a”, Chlorophyll “b”, total chlorophyll and carotenoid), as well as decreased maximum quantum efficiency of photosystem II (Fv/Fm) and net photosynthetic rate. Transcriptome analysis indicated that the impairing of photosynthesis may be responsible for plant yellowing of NAU31. Inheritance analysis showed that NAU31 was a gain-of-function mutant and the yellowing trait was controlled by a dominant gene, namely Taymg (yellow mutant gene). SSR markers analysis preliminarily mapped Taymg to the distal short arm of chromosome 2D using an F2 population from the cross between NAU31 and W7984, a synthesized wheat. The mapping result was confirmed by BSA using a 55 K wheat SNP array. Through recombinants screening, the Taymg was finely mapped to the terminal region of 2DS, flanked by markers ZH47 and gwm296 and corresponding to a physical interval of 0.76 Mb. The cloning of Taymg will facilitate the dissection of the mechanism involved in chloroplast development of wheat and the coordinating of plant development and disease resistance.

High-throughput screening of lycopene-overproducing mutants of Blakeslea trispora by combining ARTP mutation with microtiter plate cultivation and transcriptional changes revealed by RNA-seq

Abstract Random mutagenesis is still the main strategy for increasing the lycopene yield from Blakeslea trispora because of its complex, unclear genetic regulation. In this study, an effective mutation breeding method was established to obtain lycopene-overproducing mutants, and the transcriptional changes between the mutant and parent strains were then revealed by RNA-seq. After ARTP mutation and preliminary screening on solid plates, 50 color mutants were simultaneously inoculated into a microtiter plate-based system (MTPS) and traditional flasks to estimate the dependability of the high-throughput screening method. As expected, a significant linear correlation (R2 = 0.924) was observed between the absorbance of pigment in the MTPs and lycopene production in flask fermentation. A mutant (WY-239) showing a maximum lycopene concentration of 21.80 ± 1.58 mg/g was obtained, which represented a 56.27 % increment compared with the parent strain. Transcriptomic analysis showed that the carbon metabolism flowed more intensively to acetyl-CoA and then to lycopene in the WY-239 mutant compared with the parent strain. Some primary metabolic and sexual activity may be correlated with lycopene biosynthesis. The mutation breeding method could also be used as a reference for breeding other filamentous fungi, and the findings of RNA-seq can serve as a basis for metabolic engineering.

Transcriptome analysis reveals genes associated with leaf color mutants in Cymbidium longibracteatum

Cymbidium longibracteatum is an economically important Chinese orchid well known for its silver- or gold-colored leaf color patterns, and is desired for its ornamental value. In this study, we analyzed the yellow and green rhizomes from C. longibracteatum by deep RNA-sequencing. A total of 333,497 transcripts and 162,407 unigenes of ‘longchangsu’ obtained from 39.59 Gb of clean reads. Differentially expressed gene (DEG) analysis indicated that 497 genes were upregulated and 147 downregulated in the leaf color mutant. Five of these DEGs were involved in the phototransduction pathway, and 48 genes belonged to the plant-pathogen interaction pathway. Furthermore, we identified seven genes associated with the photosystem, six of which were upregulated, and one (psbA) was downregulated. Our results showed that downregulation of psbA gene may produce leaf color mutants under certain culture conditions that affect the D1 protein of photosystem II. All seven genes were validated by qRT-PCR. This study on genes related to photosystem and other pathways establishes a genetic foundation for ornamental orchids and may help to improve the economic and breeding values of C. longibracteatum.

Mutations in Domestic Animals Disrupting or Creating Pigmentation Patterns

The rich phenotypic diversity in coat and plumage color in domestic animals is primarily caused by direct selection on pigmentation phenotypes. Characteristic features are selection for viable alleles with no or only minor negative pleiotropic effects on other traits, and that alleles often evolve by accumulating several consecutive mutations in the same gene. This review provides examples of mutations that disrupt or create pigmentation patterns. White spotting patterns in domestic animals are often caused by mutations in KIT, microphthalmia transcription factor (MITF), or endothelin receptor B (EDNRB), impairing migration or survival of melanoblasts. Wild boar piglets are camouflage-colored and show a characteristic pattern of dark and light longitudinal stripes. This pattern is disrupted by mutations in Melanocortin 1 receptor (MC1R), implying that a functional MC1R receptor is required for wild-type camouflage color in pigs. The great majority of pig breeds carry MC1R mutations disrupting wild-type color and different mutations causing dominant black color were independently selected in European and Asian domestic pigs. The European allele evolved into a new allele creating a pigmentation pattern, black spotting, after acquiring a second mutation. This second mutation, an insertion of two C nucleotides in a stretch of 6 Cs, is somatically unstable and creates black spots after the open reading frame has been restored by somatic mutations. In the horse, mutations located in an enhancer downstream of TBX3 disrupt the Dun pigmentation pattern present in wild equids, a camouflage color where pigmentation on the flanks is diluted. A fascinating example of the creation of a pigmentation pattern is Sex-linked barring in chicken which is caused by the combined effect of both regulatory and coding mutations affecting the function of CDKN2A, a tumor suppressor gene associated with familial forms of melanoma in human. These examples illustrate how evolution of pigmentation patterns in domestic animals constitutes a model for evolutionary change in natural populations.

Double mutation of two homologous genes YL1 and YL2 results in a leaf yellowing phenotype in soybean [Glycine max (L.) Merr

Two homologous, chloroplast located CAAX proteases were identified to be functional redundancy in determining soybean leaf color, and they probably play essential roles in regulating light harvesting and absorption during photosynthesis process. Leaf color mutants are ideal materials for studying photosynthesis and chlorophyll metabolism. The soybean [Glycine max (L.) Merr.] yellowing leaf (yl) variation is a recombinant mutant characterized by yellow foliage, which derived from the specific cross between green seed-coated and yellow seed-coated soybean varieties. Molecular cloning and subsequent gene silencing revealed that the yellow leaf trait of yl was controlled by two recessive nuclear genes, glyma11g04660 and glyma01g40650, named as YL1 and YL2 respectively, and the latter was confirmed to be same as the earlier reported green seed-coat gene G. Both YL1 and YL2 belonged to chloroplast-located proteases possessing Abi domain, and these genes were expressed in various tissues, especially in young leaves. In yl, the expression of YL1 and YL2 were suppressed in most tissues, and the young leaf of yl presented an increased maximal photochemical efficiency (Fv/Fm) as well as enhanced net photosynthesis activity (Pn), indicating that YL1 and YL2 are involved in light absorption regulation during photosynthesis process. Collectively, the identification and description of YL1 and YL2 in our study provides insights for the regulatory mechanism of photosynthesis process, and these findings will further assist to clarify the close relationship between photosynthesis and chlorophyll metabolism.

The identification of key candidate genes mediating yellow seedling lethality in a Lilium regale mutant.

Leaf color mutants are ideal materials for exploring plant photosynthesis mechanisms, chlorophyll biosynthetic pathways and chloroplast development. The yellow seedling lethal mutant lrysl1 was discovered from self-bred progenies of Lilium regale; however, the mechanism of leaf color mutation remains unclear. In this study, the ultrastructural and physiological features and de novo RNA-Seq data of a L. regale leaf color mutant and wild-type L. regale were investigated. Genetic analysis indicated that the characteristics of the lrysl1 mutant were controlled by a recessive nuclear gene. The chlorophyll a, chlorophyll b and carotenoid contents in the mutant leaves were lower than those in the wild-type leaves. Furthermore, the contents of the chlorophyll precursors aminolevulinic acid (ALA), porphobilinogen (PBG), protoporphyrin IX (ProtoIX), Mg-protoporphyrin IX (Mg-ProtoIX), and protochlorophyll (Pchl) decreased significantly in mutant leaves. Transcriptome data from the mutant and wild type showed that a total of 892 differentially expressed genes were obtained, of which 668 and 224 were upregulated genes and downregulated genes in the mutant, respectively. Almost all genes in the photosynthesis pathway and chlorophyll biosynthetic pathway were downregulated in the mutant, which corroborated the differences in the physiological features mentioned above. Further research indicated that the chloroplasts of the mutant leaves exhibited an abnormal morphology and distribution and that the expression of a gene related to chloroplast development was downregulated. It was concluded that abnormal chloroplast development was the main cause of leaf color mutation in the mutant lrysl1 and that LrGLK was a gene related to chloroplast development in L. regale. This research provides a foundation for further research on the mechanism by which LrGLK regulates chloroplast development in L. regale.

Veterinary care of guinea pigs

Background: Guinea pigs have become very popular in the pet trade and have been extensively bred for colour and coat mutations. They should not be considered as just a children’s...

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

BackgroundLeaf 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 (Chl) biosynthesis and metabolism regulation.ResultsIn 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 1520 F3:4 yellow-colored individuals co-segregated with py1. For py2, 1860 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.ConclusionsOur 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.

Ginkgo biloba microRNA profiling reveals new insight into leaf color mutation

Abstract Ginkgo biloba (ginkgo) is a well-known ornamental tree. The yellow-leaf ginkgo mutant is an ideal material for studying leaf pigment synthesis and mutation. In this study, we used the Illumina sequencing of ginkgo small RNAs to gain insight into the function of microRNAs (miRNAs) in leaf color mutation. We constructed six small RNA libraries, and identified a total of 426 known and 265 novel miRNAs. Nineteen differentially expressed miRNAs (DEMs) were detected between the yellow-leaf and the green-leaf groups, including 8 upregulated miRNAs. The target genes of DEMs were predicted, resulting in the identification of 205 target mRNAs and 230 target gene binding sites. We found that the novel 158_mature and gma-miR2118a-3p target genes were involved in pigment biosynthesis. Three miRNAs, the novel 151_mature, ptc-miR396e-3p and aly-miR156a-5p appeared to be the potential key regulators of leaf color mutation. These DEMs and their corresponding target genes likely play key roles in the regulation of the yellow-leaf mutant. This study constructed miRNA profiles and provides new insight and a reference for related studies on miRNA regulation of leaf color pigment synthesis.