Project description:Transcriptome analyses of fruit color in strawberry white-flesh mutant reveals a possible mechanism influencing anthocyanin biosythesis
Project description:Pink-flowered strawberry is a new promising ornamental flower derived from intergeneric hybridization (Fragaria × Potentilla) with bright color, prolonged flowering period and edible fruits. However, the transcriptional events underlying anthocyanins biosynthesis pathway have not been fully characterized in its petal coloration. The pigment compounds accumulated in its fruits were the same as cultivated strawberry, but different from in its flowers. To gain insights into the regulatory networks related to anthocyanin biosynthesis and identify key genes, we performed an integrated analyses of the transcriptome and metabolomes involved in red petals at three development stages (Bud stage (L), Coloration beginning stage (Z) and Big bud stage (D)) of pink-flowered strawberry. Transcript and metabolite profiles were generated through high-throughput RNA-sequencing and high-performance liquid chromatography coupled with mass spectrometry, respectively. The results showed that the main pigments of red and dark pink petals were anthocyanins, among which cyanidins were the main compounds. There were no anthocyanins detected in white-flowered hybrids. A total of 50 285 non-redundant unigenes were obtained from the transcriptome databases, among which 59 differentially expressed genes could be identified as putative homologues of flower coloration related genes. Based on a comprehensive analysis relating pigmentation compounds to gene expression profiles, the mechanism of flower color formation was examined in pink-flowered strawberry. Furthermore, a new hypothesis explaining the lack of color phenotype of the white-flowered strawberry hybrids from the level of the transcriptome. The expression patterns of FpDFR gene and FpANS gene corresponded to the accumulation patterns of cyanidin contents in pink-flowered strawberry hybrids with different shades of pink; Whereas other anthocyanin biosynthesis genes were weakly related flower color deepened. Moreover, FpANS, FpBZ1 and FpUGT75C1 genes were the key factors that lead to the inability to accumulate anthocyanins in the white petals of PFS hybrids. Meanwhile, the competitive effect of FpFLS gene and FpDFR gene may further inhibit anthocyanin synthesis. The data presented herein are important for understanding of the molecular mechanisms underlying the petal pigmentation and will be powerful for integrating into novel genes that are potential targets for breeding new valuable pink-flowered strawberry cultivars.
Project description:Fragaria vesca, a diploid woodland strawberry with a small and sequenced genome, is an excellent model for studying fruit development. The strawberry fruit is unique in that the edible flesh is actually enlarged receptacle tissue. The true fruit are the numerous dry achenes dotting the receptacleM-^Rs surface. Auxin produced from the achene is essential for the receptacle fruit set, a paradigm for studying crosstalk between hormone signaling and development. To investigate the molecular mechanism underlying strawberry fruit set, next-generation sequencing was employed to profile early-stage fruit development with five fruit tissue types and five developmental stages from floral anthesis to enlarged fruits. This two-dimensional data set provides a systems-level view of molecular events with precise spatial and temporal resolution.
Project description:Anthocyanins are specialized plant metabolites with significant dietary value due to their antioxidant and anti-inflammatory properties. Extensive research has indicated that dietary intake of these phenolic compounds contributes to preventing various chronic diseases. Consequently, incorporating anthocyanin-rich foods into one's diet, particularly from natural sources, is highly beneficial. The tomato (Solanum lycopersicum) is the most consumed vegetable worldwide, making it an excellent candidate for anthocyanin-enrichment strategies. The activation of anthocyanin biosynthesis is light-dependent in tomato, but this mechanism has not been entirely characterized. In this study, a purple tomato line in the cv. Micro-Tom (MT-Aft/atv/hp2) was utilized to investigate cyanic fruits developed under varying light conditions. This genotype is derived from natural genetic variation and exhibits anthocyanin accumulation starting early in fruit development. Transcriptional analyses of the fruit peel (exocarp or epicarp) and flesh (mesocarp) revealed that the bHLH transcription factor SlAN1 (Solyc09g065100) is the limiting factor for anthocyanin accumulation in both tissues. In this genotype, the absence of anthocyanin accumulation in the flesh results from the sun-blocking effect of the cyanic epicarp on the mesocarp, preventing light from penetrating deeper into the fruit during its development. This research enhances our comprehension of the genetic and environmental regulation of anthocyanin accumulation in fruit tissues, offering valuable insights for plant breeding and human nutrition.
Project description:To determine the effect of different temperature on strawberry after harvest, physiological indicator analysis and proteomics analysis were conducted on ripened strawberry (‘Sweet Charlie’) fruit stored at 4 °C, 23 °C, and 37 °C (±2) for 10 or 20 days. Results showed that 4 °C maintained a better visual quality of strawberry, and the weight loss and firmness remained stable within 3 days. Low temperature negatively affected anthocyanin but positively affected soluble sugars. Though anthocyanin content was higher with increasing temperature, anthocyanin synthesis related proteins were downregulated. Higher indole-acetic acid (IAA) content in seeds and lower abscisic acid (ABA) content were found in berry at 4 °C. Antioxidant related proteins were upregulated during storage, showing a significant up-regulation of POD at 4 °C, and AsA-GSH cycle related proteins and heat shock proteins (HSPs) at 37 °C. In addition, overexpressed sugar phosphate/phosphate translocator, 1-aminocyclopropane-1-carboxylate oxidase and aquaporin PIP2-2 had a positive effect in response to low temperature stress for containing higher protopectin content and POD activity.
Project description:Peel color is a key factor that affects the fruit’s aesthetic and economic values. In Red Sugar pineapple, the peels’ red color reduces during maturation. Limited knowledge is available on the regulation of pineapple peel discoloration, which makes it important to study the molecular mechanisms associated with this important trait. Here, we report that a decrease in anthocyanin biosynthesis is predominantly associated with the pineapple peel color change during maturation. Particularly the exclusive accumulation of cyanidin in 60 days after flowering (DAF) as compared to 120 DAF gives the fruit peel its distinct reddish color. Our findings suggest that the changes in the expression of key structural genes (early and late biosynthetic genes) of the anthocyanin (cyanidin) biosynthesis pathway are responsible for peel discoloration. Based on a gene co-expression analysis and a transient expression, we identified two transcription factors i.e., AcHOX21 and AcMYB12, and showed that their downregulation leads to the reduced anthocyanin accumulation with fruit maturation.
Project description:We used Illumina sequencing to investigate the global transcriptomic expression of hormonal pathway genes in ABA initiated strawberry receptacle ripening. Expression profiles of hormone synthetic and signaling genes further demonstrated the positive roles of ABA and GA, and the negative role of auxin in receptacle ripening. We also evaluated the transcript profiling of ethylene and JA pathway genes, and the results suggested that both ethylene and JA participated in receptacle ripening. Furthermore, two novel miRNAs and three conserved miRNAs were identified and validated to target genes in ABA and auxin pathways, respectively. Our analyses reveal the molecular mechanism of hormonal regulation during strawberry receptacle ripening. The data also provide an abundant of genetic information for molecular manipulation on non-climacteric fruit ripening. Sample 1: CK0 (Strawberry fruit two weeks after athesis treated with water, set as day 0); Sample 2: CK5 (fruit treated with water on day 5); Sample 3: CK8 (fruit treated with water on day 8); Sample 4: ABA5 (fruit treated with ABA on day 5); Sample 5: ABA8 (fruit treated with ABA on day 5); Sample 6: NDGA5 (fruit treated with water on day 5); Sample 7: NDGA8 (fruit treated with NDGA on day 8).
Project description:The pink-flowered strawberry is very popular in China due to its appreciation and economic benefits and its flower has rich red petal with varying degrees, which is provided by anthocyanins accumulation. To better understand the functions of miRNAs, sRNAome, transcriptome and degradome sequencing were used to explore the target genes of miRNAs in flower development and coloring of pink-flowered strawberry. Nine small RNA libraries and a mixed degradome library from flower petals at different developmental stages were constructed and sequenced in this study. A total of 739 known miRNAs and 964 newly identified miRNAs were identified via small RNA sequencing, and their 2816 target genes were cleaved by 639 miRNAs based on the degradome data. There were 317 different expression miRNAs among flower development in pink-flowered strawberry regulated 2134 different expression target genes, which significantly enriched in the transcriptional regulation, phenylpropanoid biosynthesis and plant hormone signal transduction. Furthermore, integrated microRNAomic and transcriptomic analyses suggested that 98 miRNAs were targeted several transcription factors related to anthocyanin accumulation, in which 26 were targeted to MYBs, 12 bHLHs, 14 NACs, and 19 SPLs. And that, twenty seven different expression miRNAs may affect anthocyanin biosynthesis by regulating 23 targets participated in hormone signal transduction pathway in pink-flowered strawberry. The qRT-PCR analysis confirmed the expression changes of 21 miRNA-target pairs showed an opposite trend. Moreover, a co-expression regulatory network was constructed based on differentially expressed miRNA-targets according to the degradome data. Overall, we conducted a comparative analysis uncovered the regulatory functions of microRNAs in flower development and color changes of pink-flowered strawberry via multiple factors, including anthocyanin biosynthesis, hormone signaling and regulation factors. This work not only expands the knowledge of miRNAs affecting the coloration in strawberry, but also provides rich resources for future functional studies.
Project description:The quality of the pepper fruit is significantly influenced by the properties of its surface such as color, glossiness and texture. The fruit surface is composed of a peel containing several layers including the cuticle, epidermis and the hypodermis. The peel acts as a protective barrier against biotic and abiotic stresses and is the most critical tissue affecting water loss during post harvest storage. The peel is composed of an outer epidermis with thick waxy (lipid) cuticle and few cell layers of thick-walled hypodermal cells. Despite its agronomic importance and due to the fact that the majority of studies in fruits have been conducted using flesh and peel tissues as a whole, the biochemical and genetic bases of variation in peel properties are largely unknown. In this proposal we aim to determine peel-specific gene expression in pepper by micro array hybridizations of peel and flesh RNA extracted at different developmental stages of the fruit. The cultivar Celica (Capsicum annuum) that has a large blocky fruit will be used for studying gene expression in the peel and flesh. Plants were grown in the greenhouse during the spring of 2006. Fruits were harvested at three developmental stages: young- 10 days after anthesis, mature green- 30 days after anthesis and ripe red- 45 days after anthesis. These stages were chosen because each represents a distinct phase in fruit development. At each stage, a biological replicate consists of bulked tissue from 3 fruits from each of 3 plants (a total of 9 fruits). We have a total of 4 biological replicates. For each fruit, the peel was separated from the flesh by manual dissection using thin forceps and scalpel blade. Peel and flesh samples were immediately frozen in liquid nitrogen and stored at -800C until RNA extraction. Total RNA was extracted using the GenElute Mammalian Total RNA Miniprep kit (Sigma). Keywords: Reference design