Weeks After Flowering Research Articles

Fruit and Seed Development of Citrus aurantifolia (Christm.) Swingle ‘Pan Rampai’ Cultivar

The ‘Pan Rampai’ cultivar of Mexican lime is highly consumed for its lime aroma and high juice content. However, occasional instances of low juice content could be found, potentially due to premature harvesting. Moreover, the seed development of the ‘Pan Rampai’ lime has never been investigated. Hence, this study was aimed to explore the development process of the ‘Pan Rampai’ lime fruit, focusing on its fruit weight, juice weight, juice content, fruit diameter, fruit length, fruit rind thickness, total soluble solids, titratable acid, TSS/TA ratio, and vitamin C content over the period of 11 to 18 weeks after flowering (WAF). Additionally, we examined the seed development by observing seed width, length, thickness, and germination percentage. Our findings revealed that fruit weight, juice weight, juice content, fruit diameter, and fruit length exhibited a consistent increase throughout the fruit development stages, while the fruit rind thickness decreased. Seed width and thickness remained relatively stable over 11 to 18 WAF, whereas seed length gradually increased. The study of germination percentage indicated that seed germination was mature from the 15th WAF, coinciding with the appearance of the secondary wall of seed coat. There results provide crucial insights into the optimal harvesting periods for juice (from 17 WAF) and seed (from 15 WAF) for the ‘Pan Rampai’ lime cultivar.

Impact of Harvesting Time on Grain Yield, Physicochemical Attributes, and 2-Acetyl-1-pyrroline Biosynthesis in Aromatic Rice

Achieving a consistent grain yield while preserving persistent aroma remains a substantial challenge in aromatic rice production in Bangladesh. To address this challenge, a field experiment was conducted at the agronomy research area of Sher-e-Bangla Agricultural University, Dhaka-1207, between 15 June 2022, and 25 November 2022 (Aman season). This study aimed to evaluate the influence of harvesting time on aromatic rice performance. The experiment, following a randomized complete block design with three replications, involved two factors: factor 1 comprised various rice varieties [Bangladesh Rice Research Institute (BRRI) dhan34, BRRI dhan70, BRRI dhan80, and Tulshimala], and factor 2 comprised three harvesting times [3, 4, and 5 weeks after flowering (WAF)]. Results revealed significant impacts of variety and/or harvesting time on grain yield, physicochemical characteristics, and aroma of aromatic rice. Notably, Tulshimala and BRRI dhan80 exhibited superior milling quality, biochemical properties, and aroma characteristics among the aromatic rice types. BRRI dhan70 and BRRI dhan80 displayed higher grain yield when harvested at 5 WAF. However, Tulshimala and BRRI dhan80 showed superiority in grain 2-acetyl-1-pyrroline (2-AP) concentration when harvested 3 or 4 WAF. Earlier harvesting at 3 and 4 WAF resulted in higher percentages of grain 2-AP (60.22% and 53.96%, respectively) compared with later harvesting at 5 WAF (used as check). In conclusion, varying harvesting times markedly impact the yield, physiochemical characteristics, and aroma of aromatic rice varieties, with earlier harvesting beneficial for aroma retention in Tulshimala and BRRI Dhan80 and later harvesting for increased economic yield in BRRI dhan70 and BRRI dhan80.

Stone cell formation in the pedicel of pears and apples.

For the first time, stone cells in pear and apple pedicel were studied. The lignification of the pedicel outer part was correlated with flesh, and the secondary cell wall biosynthesis genes were activated. Fruit pedicels act as bridges between the fruit and the shoot. They have secondary thickened cell walls that presumably function in mechanical support, water and nutrient transport. Stone cells are cells with a secondary cell wall thickening. In pears, yet not in apples, the stone cells affect the flesh texture. There have been few reports on stone cell formation in pear and apple pedicels; therefore, we studied these cells for the first time. The apple pedicel had few stone cells in the cortex. The formation of stone cells in pear continued until seven weeks after flowering (WAF), and the density was significantly higher than in apple. The stone cell formation degree (SFD) of pear was 3.6-7.1 times higher than that of apple. Total lignin and lignin non-condensed structure (G and S units) content in the pear pedicle outer part was 1.5-2.7 times higher than that of the apple at harvest. The SFD of the pedicel outer part had a positive correlation with the G and S units content of the flesh. The total lignin and G and S units content between flesh and the pedicel outer part were positively correlated. Correlation analysis revealed a positive relationship between fruit and pedicel formation of the stone cells. The WGCNA showed that NST3 was linked to NAC028, MYB46, CESA, POD, LAC, and VSR6. These genes were highly expressed in the outer part of the pear pedicel, while they were suppressed in that issue of the apple at 4 WAF.

Characterization of odor-contributing volatile in Capsicum chinense ‘JT-1’fruits during development and transcriptome analysis of key fruit-aroma formation periods

Chili pepper (Capsicum spp.) is one of the world's most popular vegetables and spices. C. chinense is a widely consumed domesticated pepper species. Most varieties of this species have distinctive fruity aromas, a trait with high commercial value. Studies have shown that branched-chain esters are the main contributors to the fruity aroma; however, the mechanisms of their accumulation and regulation remain elusive. In this work, we conducted gas chromatography–olfactometry–mass spectrometry analysis of C. chinense pepper ‘JT-1’ fruits harvested from 1 to 7 weeks after flowering (WAF). The main odor-contributing volatile of fruity aroma in ‘JT-1’ fruits was 4-methylpentyl 3-methylbutanoate, the concentration of which dramatically increased at 4 WAF. A shift in the dominant volatile organic compound (VOC) profile from aldehydes and alcohols to esters occurred from 3 to 4 WAF. Transcriptome analysis of fruits at these two stages and qPCR results revealed that the up-regulating of CcBcat4 may play an essential role in accumulating of 4-methylpentyl 3-methylbutanoate in chili pepper. Our findings shed light on the molecular mechanism of aroma biosynthesis in pepper and provide a theoretical basis for the molecular breeding of high-quality pepper fruits.

Rain-shelter Cultivation Affects the Accumulation of Volatiles in ‘Shuijing’ Grape Berries during Development

Rain-shelter cultivation could protect grape berries from many diseases and affect grape berry quality. However, there have been few studies of the effects of rain-shelter cultivation on the accumulation of volatiles in Shuijing grapes grown in Yunnan Province. Therefore, the goal of this research was to explore the effects of rain-shelter cultivation on the accumulation of volatiles in Shuijing grape berries during development. The Shuijing grapes used during this study were grown in the Yunnan Province of southwest China in two consecutive vintages (2018 and 2019). The results showed that rain-shelter cultivation promoted grape ripening and inhibited volatiles synthesis in Shuijing grape berries. However, the application of rain shelters did not affect the accumulation patterns of volatiles; instead, it affected the concentrations of volatiles in Shuijing grape berries, especially during the maturation phase [12–15 weeks after flowering (WAF)]. The concentrations of isoprenoid-derived volatiles (2019), fatty acid-derived volatiles, and amino acid-derived benzenoids in Shuijing grape berries were decreased by rain-shelter cultivation during the maturation phase. The concentration of 2,5-dimethyl-4-methoxy-3(2H)-furanone (mesifurane) was also decreased by rain-shelter cultivation during the late maturation phase (14 and 15 WAF). A principal component analysis (PCA) indicated that the vintage had a much greater influence on the physicochemical parameters and volatiles of the Shuijing grape berries than the cultivation method. This work reveals the formation and accumulation patterns of volatiles of Shuijing grape berries under rain-shelter cultivation during development and has significance for exploring the potential of rain-shelter cultivation in grape-producing regions with excessive rainfall.

The difference of quality of citrus fruits on different levels of maturity during storage period

This research was conducted at farmers’ oranges field in Belantih Village, Kintamani District, Bangli Regency, Bali, and Laboratory of Agriculture Faculty of Warmadewa University. The aim of the study was to know the difference of quality of Siam citrus fruits at different fruit maturity levels during storage period. The experiment used randomized block design. The treatment was fruit maturity, consisting of 4 levels i.e FM1 = harvested 22 weeks after flowering (WAF) with physical appearance of green fruit skin, FM2 = harvested at 24 WAF with green yellowish fruit skin, FM3 = harvested at 26 WAF with yellow-greenish fruit skin, and FM4 = harvested at 28WAF with yellow fruit skin, each repeated 6 times. The results showed, the riper harvested fruit the sweeter the taste, which reflected by the higher total dissolved solids and sugar/acid ratio, but the shelf life was shorter because the fruits were rapidly shrinking and loss of weight and quickly damaged. However, if the fruits harvested too young (before the age of 26 WAF) the quality of the fruits were low reflected by lower of weight per fruit and fruit diameter and decreased the quality of the fruit during storage was faster. Based on the result of this research, to get good quality of Siam Citrus fruit and kept longer on storage the fruit harvest should be done at age 26 WAF with physical appearance characteristic of yellow green fruit skin.

Transcriptional profiling between yellow- and black-seeded Brassica napus reveals molecular modulations on flavonoid and fatty acid content

Brassica napus is an important cash crop broadly grown for the vegetable and oil values. Yellow-seeded B. napus is preferred by breeders due to its improved oil and protein quality, less pigments and lignin compared with the black-seeded counterpart. This study compared the differences in flavonoid and fatty acid contents between yellow rapeseed from the progenies of B. napus–Sinapis alba somatic hybrids and the black-seeded counterpart using RNA-seq analysis. Through HPLC-PDA-ESI(−)/MS2 analysis, it was found that phenylpropanoids and flavonoids (i.e., isorhamnetin, epicatechin, kaempferol, and other derivatives) in yellow seed were significantly lower than those in black seed. The fatty acid (FA) content in yellow rapeseed was higher than that in black rapeseed due to the variation of C16:0, C18:0, C18:1, C18:2, and C18:3 contents. RNA-seq analysis of seeds at four and five weeks after flowering (WAF) indicated that differentially expressed genes (DEGs) between black and yellow rapeseeds were enriched in flavonoid and FA biosynthesis, including BnTT3, BnTT4, BnTT18, and BnFAD2. Also, genes related to FA biosynthesis, desaturation and elongation (FAD3, LEC1, FUS3, and LPAT2) in yellow seed were up-regulated compared to those in black seed, while genes involved in beta-oxidation cycle (AIM1 and KAT2) of yellow seed were down-regulated compared to those in black seed. The DEGs related to the variation of flavonoids, phenylpropanoids, and FAs would help improve the knowledge of yellow seed character in B. napus and promote rapeseed improvement.

Study of the olive β-glucosidase gene family putatively involved in the synthesis of phenolic compounds of virgin olive oil.

Hydrolysis of the fruit phenolic glucosides occurring during the oil extraction process is the main biochemical reaction affecting the biosynthesis and accumulation of secoiridoid compounds in virgin olive oil. An integrated approach at the molecular, biochemical, and metabolic level was used to study the olive β-glucosidase gene family in seven olive cultivars selected by their different phenolic profiles. Eight β-glucosidase genes have been identified by in silico analysis of an olive transcriptome. Their expression levels were analyzed by reverse transcription quantitative polymerase chain reaction in olive fruits at different ripening stages: I, green fruits, 16-19 weeks after flowering (WAF); II, yellow-green fruits, 22-25 WAF; III, turning fruits, 28-31 WAF; and IV, fully ripe fruits, 35-40 WAF. Gene expression was compared with the level of β-glucosidase activity in the fruit and with the phenolic composition of fruits and oils from different olive cultivars. Phylogenetic analysis of the encoded proteins and differences found among the β-glucosidase genes based on Gene Ontology enrichment analysis data suggests maximum involvement of two genes, OeBGLU1A and OeBGLU1B, in the phenolic composition of virgin olive oil. Positive correlation coefficients were found within each olive cultivar between OeBGLU1A and OeBGLU1B gene expression data and the phenolic content of the oil. The results obtained suggest that the expression pattern of specific β-glucosidase genes may be an accurate predictor for the phenolic content of virgin olive oil that could be used in olive breeding programs. © 2021 Society of Chemical Industry.

Comparison and characterization of galactomannan at different developmental stages of Gleditsia sinensis Lam.

Pods from a Gleditsia sinensis Lam. tree were collected and the galactomannan content and other properties were determined at their different developmental stages. In green and immature seed, galactomannan was substituted to a great extent with a mannose to galactose (M/G) ratio of 2.4 from crude polysaccharides. During late galactomannan deposition, it was substituted to a lower extent and this ratio increased rapidly, reaching a M/G ratio of 3.1. Average molecular weight (Mw) of the extracted polysaccharides first increased, reached the maximum (1.19 × 106) at 17 weeks after flowering (WAF), and then decreased. These changes might result from primary galactomannan biosynthesis and from galactose removal by α-galactosidase in the endosperm. The solubility of crude polysaccharides decreased with increased M/G ratio and maximum solubility was more than 89% that collected at 13 WAF. Rheological properties showed that apparent viscosity was largely influenced by the molecular weight and M/G ratio of galactomannans.

Correlation Analysis of Phenolic Contents and Antioxidation in Yellow- and Black-Seeded Brassica napus.

Brassica napus L. is rich in phenolic components and it has natural antioxidant characteristics which are important to human health. In the present study, the total phenolic and flavonoid contents of developing seeds of yellow- and black-seeded B. napus were compared. Both phenolic and flavonoid contents were significantly higher at 5 weeks after flowering (WAF) in black seeds (6.44 ± 0.97 mg EE/g phenolics and 3.78 ± 0.05 mg EE/g flavonoids) than yellow seeds (2.80 ± 0.13 mg/g phenolics and 0.83 ± 0.01 mg/g flavonoids). HPLC–DAD–ESI/MS analysis revealed different content of 56 phenolic components between yellow and black-seeded B. napus, including kaempferol-3-O-glucoside, isorhamnetin-3-O-glucoside, quercetin-3-O-sophoroside, procyanidin B2 ([DP 2]), which were significantly reduced in yellow seeds compared with black seeds. Applying the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical assay, we found maximum clearance of DPPH and ABTS in the late developmental stages of yellow and black seeds. Additionally, the ferric reducing antioxidant power (FRAP) value maximized at 5 WAF in black seeds (432.52 ± 69.98 μmol Fe (II)/g DW) and 6 WAF in yellow seeds (274.08 ± 2.40 μmol Fe (II)/g DW). Generally, antioxidant ability was significantly reduced in yellow-seeded B. napus compared to black rapeseed, and positive correlations between antioxidation and flavonoid content were found in both yellow- and black-seeded B. napus.

Study on russet-related enzymatic activity and gene expression in ‘Shine Muscat’ grape treated with GA3 and CPPU

ABSTRACTPhysiological (metabolite analysis) and molecular (gene expression) approaches were used to understand the mechanism underlying russet formation in response to the application of GA3 and CPPU (Forchlorfenuron) in a Japanese table grape cultivar ‘Shine Muscat’. Several different concentrations of GA3 and GA3 + CPPU [25 mg L−1 GA3 (A), 25 mg L−1 GA3 + 5 mg L−1 CPPU (B), 25 mg L−1 GA3 + 10 mg L−1 CPPU (C), and 25 mg L−1 GA3 + 15 mg L−1 CPPU (D)] were applied to grape berry clusters at two weeks after flowering (WAF). No russet was observed on the berries treated with the ‘C’ combination. Lower levels of phenylalanine ammonia-lyase (PAL) activity was observed in the treated samples, relative to the untreated material. Reduced peroxide (POD) activity was also observed in response to different treatments, while the expression of Peroxidase 17 and Phenylalanine ammonia-lyase G1 genes mirrored lignin content. Increased activity of 4-coenzyme A ligase (4CL) may contribute to decreasing the level of russet and help to improve grape berry quality.

Endosperm-derived triploid plant regeneration in diploid Actinidia kolomikta, a cold-hardy kiwifruit relative

Endosperm culture is a unique technique for producing a triploid plant from diploid plants. In the present study, endosperm of a diploid cold-hardy kiwifruit relative, Actinidia kolomikta (Maxim. & Rupr.) Maxim., was cultured to regenerate triploid plants and expand ploidy variation in this mostly diploid species. Endosperm derived from fruits harvested 6–10 weeks after flowering (WAF) was used for the initial explants to examine the effect of plant growth regulators on callus formation and organogenesis. The endosperm-derived calli induced in MS medium with above 1.0mgL−1 of 2,4-dichlorophenoxyacetic acid (2,4-D) were soft, small, and translucent, and no morphogenic response was observed. Conversely, the endosperm-derived yellow-green calli induced in the medium with 2,4-D (0.1mgL−1) plus kinetin (1.0, 2.0, and 5.0mgL−1) were hard, compact, fast growing, and showed adventitious shoot primordia. These primordia elongated into shoots when the calli were transferred to MS medium supplemented with zeatin (1.0, 2.0, and 4.0mgL−1) under continuous light conditions. The shoots developed roots on half-strength MS medium lacking plant growth regulators. In total, 14 plants were obtained. Flow cytometry and chromosomal analysis confirmed that the regenerated plants were triploid, suggesting that the plant tissue originated from the endosperm. This study reveals that the endosperm of A. kolomikta has plant regeneration abilities and that the regenerated plants have the same ploidy level as the endosperm (triploid). These results may be of use for ploidy manipulation or polyploidy breeding in other species in the genus Actinidia.

Regulation of On-Tree Vitamin E Biosynthesis in Olive Fruit during Successive Growing Years: The Impact of Fruit Development and Environmental Cues.

The term vitamin E refers to a group of eight lipophilic compounds known as tocochromanols. The tocochromanols are divided into two groups, that is, tocopherols and tocotrienols, with four forms each, namely α-, β-, γ-, and δ-. In order to explore the temporal biosynthesis of tocochromanols in olive (Olea europaea cv. ‘Koroneiki’) fruit during on-tree development and ripening over successive growing years, a combined array of analytical, molecular, bioinformatic, immunoblotting, and antioxidant techniques were employed. Fruits were harvested at eight successive developmental stages [10–30 weeks after flowering (WAF)], over three consecutive years. Intriguingly, climatic conditions affected relative transcription levels of vitamin E biosynthetic enzymes; a general suppression to induction pattern (excluding VTE5) was monitored moving from the 1st to the 3rd growing year, probably correlated to decreasing rainfall levels and higher temperature, particularly at the fruit ripening stage. A gradual diminution of VTE5 protein content was detected during the fruit development of each year, with a marked decrease occurring after 16 WAF. Alpha-tocopherol was the most abundant metabolite with an average percentage of 96.82 ± 0.23%, 91.13 ± 0.95%, and 88.53 ± 0.96% (during the 1st, 2nd, and 3rd year, respectively) of total vitamin E content in 10–30 WAF. The concentrations of α-tocopherol revealed a generally declining pattern, both during the on-tree ripening of the olive fruit and across the 3 years, accompanied by a parallel decline of the total antioxidant capacity of the drupe. Contrarily, all other tocochromanols demonstrated an inverse pattern with lowest levels being recorded during the 1st year. It is likely that, in a defense attempt against water deficit conditions and increased air temperature, transcription of genes involved in vitamin E biosynthesis (excluding VTE5) is up-regulated in olive fruit, probably leading to the blocking/deactivating of the pathway through a negative feedback regulatory mechanism.

Temporal analysis reveals a key role for VTE5 in vitamin E biosynthesis in olive fruit during on-tree development.

The aim of this work was to generate a high resolution temporal mapping of the biosynthetic pathway of vitamin E in olive fruit (Olea europaea cv. “Koroneiki”) during 17 successive on-tree developmental stages. Fruit material was collected from the middle of June until the end of January, corresponding to 6–38 weeks after flowering (WAF). Results revealed a variable gene regulation pattern among 6–38 WAF studied and more pronounced levels of differential regulation of gene expression for the first and intermediate genes in the biosynthetic pathway (VTE5, geranylgeranyl reductase, HPPD, VTE2, HGGT and VTE3) compared with the downstream components of the pathway (VTE1 and VTE4). Notably, expression of HGGT and VTE2 genes were significantly suppressed throughout the developmental stages examined. Metabolite analysis indicated that the first and intermediate stages of development (6–22 WAF) have higher concentrations of tocochromanols compared with the last on-tree stages (starting from 24 WAF onwards). The concentration of α-tocopherol (16.15 ± 0.60−32.45 ± 0.54 mg/100 g F.W.) were substantially greater (up to 100-fold) than those of β-, γ-, and δ-tocopherols (0.13 ± 0.01−0.25 ± 0.03 mg/100 g F.W., 0.13 ± 0.01−0.33 ± 0.04 mg/100 g F.W., 0.14 ± 0.01−0.28 ± 0.01 mg/100 g F.W., respectively). In regard with tocotrienol content, only γ-tocotrienol was detected. Overall, olive fruits (cv. “Koroneiki”) exhibited higher concentrations of vitamin E until 22 WAF as compared with later WAF, concomitant with the expression profile of phytol kinase (VTE5), which could be used as a marker gene due to its importance in the biosynthesis of vitamin E. To the best of our knowledge, this is the first study that explores the complete biosynthetic pathway of vitamin E in a fruit tree crop of great horticultural importance such as olive, linking molecular gene expression analysis with tocochromanol content.

Expression of structural genes related to anthocyanin biosynthesis of Vitis amurensis

This research was designed to assess the changes in anthocyanin content in grape skins of Vitis amurensis and to explore mRNA transcriptions of 11 structural genes (PAL, CHS3, CHI1, F3H2, F3′H, F3′5′H, DFR, LDOX, UFGT, OMT and GST) related to anthocyanin biosynthesis during grape berry development, by the use of HPLC-MS/MS and real-time Q-PCR analysis. Accumulation of anthocyanins began at veraison, continued throughout the later berry development and reached a peak at maturity. Veraison is the time when the berries turn from green to purple. Expression of PAL, CHI1, and LDOX were up-regulated from 2 to 4 weeks after flowering (WAF), down-regulated from 6 WAF to veraison, whereas DFR was up-regulated at 8 WAF, and then up-regulated from veraison to maturity. CHS3, F3′5′H, UFGT, GST, and OMT were down-regulated from 2 WAF to veraison, and then up-regulated from veraison to maturity. The transcriptional expressions of the 11 structural genes also showed positive correlations with the anthocyanin content from veraison to maturity. Positive correlations were also observed between OMT transcriptional level and the content of methoxyl-anthocyanins, and between F3′5′H transcriptional level and the content of delphinidin anthocyanins. F3H2 and F3′H expression was up-regulated at 2 WAF. F3H2 expression was down-regulated from 4 WAF to veraison and then up-regulated again from veraison to maturity. F3′H expression was down-regulated at 4 WAF and then up-regulated again from 6 WAF to maturity. F3′H transcriptional level was correlated positively with the cyanidin anthocyanin concentration from veraison to maturity. These results indicate that the onset of anthocyanin synthesis during berry development coincides with a coordinated increase in the expression of a number of genes in the anthocyanin biosynthetic pathway.

Gene expression profiling for seed protein and oil synthesis during early seed development in soybean

Soybean (Glycine max L.) is one of the most important crops because of its high seed contents of protein and oil. However, little is known about the molecular regulation of seed filling during accumulation of seed protein and oil storage products. We identified soybean homologs of Arabidopsis genes involved in metabolic pathways of carbon precursors, protein, and oil, and analyzed gene expression patterns in immature seeds at 1 and 2 weeks after flowering (WAF). G. max undergoes two rounds of whole-genome duplication; the number of genes involved in the three synthesis pathways is more than two times higher than that in Arabidopsis. Among these genes, five were conserved as single-copy genes and 44 were high copy gene families consisting of more than seven homolog members. We identified five differentially expressed genes in immature seeds aged between 1 and 2 WAF, including CELL WALL INVERTASE, BRANCHED-CHAIN AMINO ACID TRANSAMINASE, AMINO ACID PERMEASE, ALDEHYDE REDUCTASE, and BIOTIN CARBOXYL CARRIER PROTEIN. Expression analysis of the duplicated genes on the synteny block revealed that the duplicated genes involved in protein synthesis had stronger positive correlations between their expression patterns than those of oil synthesis genes. This study provides novel insights into the molecular details of genes associated with soybean seed protein and oil synthesis pathways. These genes can be used as tools to improve seed nutrient composition.

Identification and characterization of microRNAs from Chinese pollination constant non-astringent persimmon using high-throughput sequencing.

BackgroundmicroRNAs (miRNAs) have been shown to play key roles in regulating gene expression at post-transcriptional level, but miRNAs associated with natural deastringency of Chinese pollination-constant nonastringent persimmon (CPCNA) have never been identified.ResultsIn this study, two small RNA libraries established using ‘Eshi No. 1’ persimmon (Diospyros kaki Thunb.; CPCNA) fruits collected at 15 and 20 weeks after flowering (WAF) were sequenced through Solexa platform in order to identify miRNAs involved in deastringency of persimmon. A total of 6,258,487 and 7,634,169 reads were generated for the libraries at 15 and 20 WAF, respectively. Based on sequence similarity and hairpin structure prediction, 236 known miRNAs belonging to 65 miRNA families and 33 novel miRNAs were identified using persimmon transcriptome data. Sixty one of the characterized miRNAs exhibited pronounced difference in the expression levels between 15 and 20 WAF, 17 up-regulated and 44 down-regulated. Expression profiles of 12 conserved and 10 novel miRNAs were validated by stem loop qRT-PCR. A total of 198 target genes were predicted for the differentially expressed miRNAs, including several genes that have been reported to be implicated in proanthocyanidins (PAs, or called tannin) accumulation. In addition, two transcription factors, a GRF and a bHLH, were experimentally confirmed as the targets of dka-miR396 and dka-miR395, respectively.ConclusionsTaken together, the present data unraveled several important miRNAs in persimmon. Among them, miR395p-3p and miR858b may regulate bHLH and MYB, respectively, which are influenced by SPL under the control of miR156j-5p and in turn regulate the structural genes involved in PA biosynthesis. In addition, dka-miR396g and miR2911a may regulate their target genes associated with glucosylation and insolubilization of tannin precursors. All of these miRNAs might play key roles in the regulation of (de)astringency in persimmon fruits under normal development conditions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0400-6) contains supplementary material, which is available to authorized users.

Proteomic analysis of embryogenesis and the acquisition of seed dormancy in Norway maple (Acer platanoides L.).

The proteome of zygotic embryos of Acer platanoides L. was analyzed via high-resolution 2D-SDS-PAGE and MS/MS in order to: (1) identify significant physiological processes associated with embryo development; and (2) identify changes in the proteome of the embryo associated with the acquisition of seed dormancy. Seventeen spots were identified as associated with morphogenesis at 10 to 13 weeks after flowering (WAF). Thirty-three spots were associated with maturation of the embryo at 14 to 22 WAF. The greatest changes in protein abundance occurred at 22 WAF, when seeds become fully mature. Overall, the stage of morphogenesis was characterized by changes in the abundance of proteins (tubulins and actin) associated with the growth and development of the embryo. Enzymes related to energy supply were especially elevated, most likely due to the energy demand associated with rapid growth and cell division. The stage of maturation is crucial to the establishment of seed dormancy and is associated with a higher abundance of proteins involved in genetic information processing, energy and carbon metabolism and cellular and antioxidant processes. Results indicated that a glycine-rich RNA-binding protein and proteasome proteins may be directly involved in dormancy acquisition control, and future studies are warranted to verify this association.

Expression of Structural Genes Related to Anthocyanin Biosynthesis of <i>Vitis amurensis</i>

The accumulation of anthocyanins in skins is one of the main features of red grape berry ripening. This research was designed to assess the changes in anthocyanin content in grape skins of V. amurensis and to explore mRNA transcriptions of 11 structural genes (PAL, CHS3, CHI1, F3H2, F3'H, F3'5'H, DFR, LDOX, UFGT, OMT and GST) related to anthocyanin biosynthesis during grape berry development, by the use of HPLC-MS/MS and real-time Q-PCR analysis. Accumulation of anthocyanins began at veraison, continued throughout the later berry development and reached a peak at maturity. Veraison is the time when the berries turn from green to purple. Expression of PAL, CHI1, and LDOX were up-regulated from 2 to 4 weeks after flowering (WAF), down-regulated from 6 WAF to veraison, whereas DFR was up-regulated at 8 WAF, and then up-regulated from veraison to maturity. The expression of these genes at the transcriptional level had a positive correlation with the content of anthocyanins from veraison to maturity. The CHS3, F3'5'H, UFGT, GST, and OMT were down-regulated from 2 WAF to veraison, and then up-regulated from veraison to maturity. The transcriptional expressions of the 11 structural genes also showed positive correlations with the anthocyanin content from veraison to maturity. Positive correlations were also observed between OMT transcriptional level and the content of methoxyl-anthocyanins and between F3'5'H transcriptional level and the content of delphinidin anthocyanins. F3H2 and F3'H expression was up-regulated at 2 WAF. F3H2 expression was down-regulated from 4 WAF to veraison and then up-regulated again from veraison to maturity. F3'H expression was down-regulated at 4 WAF and then up-regulated again from 6 WAF to maturity. F3'H transcriptional level was correlated positively with the cyanidin anthocyanin concentration from veraison to maturity. These results indicate that the onset of anthocyanin synthesis during berry development coincides with a coordinated increase in the expression of a number of genes in the anthocyanin biosynthetic pathway.

Transcriptome analysis of fruit development of a citrus late-ripening mutant by microarray

Mingliutianju ( Citrus reticuiata Blanco cv.Mingliutianju, MP) is a novel late ripening cultivar selected from Chuntianju ( Citrus reticuiata Blanco cv.Chuntianju, CP) through spontaneous bud mutation. Large-scale analysis of gene expression differences between of peels of MP and CP is studied during the course of 12 weeks and 23 weeks after flowering (WAF) using Affymetrix GeneChip ® citrus genome array to provide new insights into the mechanisms behind this bud mutation. Altogether, 395 differentially expressed genes are identified including 132 up-regulated and 263 down-regulated genes. Singular enrichment analysis (SEA) and parametric analysis of gene set enrichment (PAGE) are performed and 7 statistically significant differentially expressed genes are selected finally for further study. Results from semiquantitative RT-PCR performed on these 7 genes show that one gene's expression situation is totally correlated with that observed with the microarray. These seven genes include three UDP-glucosyltransferase genes, two disease resistance-responsive protein-related genes, one chitinase gene and one protein kinase family protein gene, all of which are involved in 18 different biological processes according to the hierarchical tree of annotated gene ontology (GO) terms. The candidate biological process and its relation to bud mutation are discussed.