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Li Wang - One of the best experts on this subject based on the ideXlab platform.
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the conserved and particular roles of r2r3 myb regulator fhpap1 from Freesia hybrida in flower anthocyanin biosynthesis
Plant and Cell Physiology, 2020Co-Authors: Yueqing Li, Xiaotong Shan, Shucai Wang, Linna Tong, Keyu Lu, Shuying Li, Shadrack Kimani, Li WangAbstract:Anthocyanin biosynthesis is mainly controlled by MYB-bHLH-WD40 (MBW) complexes that modulate the expression of anthocyanin biosynthetic genes. The MYB regulators involved in anthocyanin biosynthesis arose early during plant evolution, and thus might function divergently in different evolutionary lineages. Although the anthocyanin-promoting R2R3-MYB regulators in eudicots have been comprehensively explored, little consensus has been reached about functional discrepancies versus conservation among MYB regulators from different plant lineages. Here we integrated transcriptome analysis, gene expression profiles, gain-of-function experiments and transient protoplast transfection assays to functionally characterize the monocot Freesia hybrida anthocyanin MYB regulator gene FhPAP1 which showed correlations with late anthocyanin biosynthetic genes. FhPAP1 could activate anthocyanin biosynthetic genes as well as TT8-clade genes FhTT8L, AtTT8 and NtAN1 when overexpressed in Freesia, Arabidopsis and tobacco, respectively. Consistently, FhPAP1 could interact with FhTT8L and FhTTG1 to form the conserved MBW complex and shared similar target genes with its orthologs from Arabidopsis. Most prominently, FhPAP1 displayed higher transactivation capacity than its homologs in Arabidopsis and tobacco, which was instantiated in its powerful regulation on anthocyanin biosynthetic genes. Moreover, we found that FhPAP1 might be the selected gene during the domestication and rapid evolution of the wild Freesia species to generate intensive flower pigmentation. These results showed that while the MBW complex was highly evolutionarily conserved between tested monocot and core eudicot plants, participating MYB regulators showed functional differences in transactivation capacity according to their activation domain and played important roles in the flower coloration domestication and evolution of angiosperms.
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functional differentiation of duplicated flavonoid 3 o glycosyltransferases in the flavonol and anthocyanin biosynthesis of Freesia hybrida
Frontiers in Plant Science, 2019Co-Authors: Xiangyu Meng, Xiaotong Shan, Yueqing Li, Tongtong Zhou, Li WangAbstract:Flavonols and anthocyanins are two widely distributed groups of flavonoids that occurred apart during plant evolution and biosynthesized by shared specific enzymes involved in flavonoid metabolism. UDP-glucose, flavonoid 3-O-glycosyltransferase (UF3GT), is one of the common enzymes which could catalyze the glycosylation of both flavonol and anthocyanidin aglycons simultaneously in vitro. However, whether and how UF3GT paralogous genes function diversely at the biochemical and transcriptional levels are largely unknown. Recently, Fh3GT1 was identified to be a member of UF3GTs in Freesia hybrida. However, its expression patterns and enzymatic characteristics could not coincide well with flavonol accumulation. In an attempt to characterize other flavonoids, especially flavonol glycosyltransferase genes in Freesia, three closest candidate UFGT genes-Fh3GT2, Fh3GT3, and Fh3GT4-were mined from the Freesia transcriptomic database and isolated from the flowers of the widely distributed Freesia cultivar, Red River®. Based on bioinformatic analysis and enzymatic assays, Fh3GT2 turned out to be another bona fide glycosyltransferase gene. Biochemical analysis further proved that Fh3GT2 preferentially glucosylated kaempferol while Fh3GT1 controlled the glucosylation of quercetin and anthocyanidins. In addition, transfection assays demonstrated that Fh3GT2 could be mainly activated by the flavonol regulator FhMYBF1 or the anthocyanin regulator FhPAP1, whereas Fh3GT1 could only be activated by FhPAP1. These findings suggested that Fh3GTs might have functionally diverged in flavonoid biosynthesis at both the biochemical and transcriptional levels.
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a functional homologue of arabidopsis ttg1 from Freesia interacts with bhlh proteins to regulate anthocyanin and proanthocyanidin biosynthesis in both Freesia hybrida and arabidopsis thaliana
Plant Physiology and Biochemistry, 2019Co-Authors: Xiaotong Shan, Yueqing Li, Liudi Zhou, Song Yang, Shucai Wang, Li WangAbstract:The MBW complex, consisting of MYB, basic helix-loop-helix (bHLH) and WD40 proteins, regulates multiple traits in plants, such as anthocyanin and proanthocyanidin biosynthesis and cell fate determination. The complex has been widely identified in dicot plants, whereas few studies are concentrated on monocot plants which are of crucial importance to decipher its functional diversities among angiosperms during evolution. In present study, a WD40 gene from Freesia hybrida, designated as FhTTG1, was cloned and functionally characterized. Real-time PCR analysis indicated that it was expressed synchronously with the accumulation of both proanthocyanidins and anthocyanins in Freesia flowers. Transient protoplast transfection and biomolecular fluorescence complementation (BiFC) assays demonstrated that FhTTG1 could interact with FhbHLH proteins (FhTT8L and FhGL3L) to constitute the MBW complex. Moreover, the transportation of FhTTG1 to nucleus was found to rely on FhbHLH factors. Outstandingly, FhTTG1 could highly activate the anthocyanin or proanthocyanidin biosynthesis related gene promoters when co-transfected with MYB and bHLH partners, implying that FhTTG1 functioned as a member of MBW complex to control the anthocyanin or proanthocyanidin biosynthesis in Freesia hybrida. Further ectopic expression assays in Arabidopsis ttg1-1 showed the defective phenotypes of ttg1-1 were partially restored. Molecular biological assays validated FhTTG1 might interact with the endogenous bHLH factors to up-regulate genes responsible for anthocyanin and proanthocyanidin biosynthesis and trichome formation, indicating that FhTTG1 might perform exchangeable roles with AtTTG1. These results will not only contribute to the characterization of FhTTG1 in Freesia but also shed light on the establishment of flavonoid regulatory system in monocot plants, especially in Freesia hybrida.
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efficient isolation of protoplasts from Freesia callus and its application in transient expression assays
Plant Cell Tissue and Organ Culture, 2019Co-Authors: Xiaotong Shan, Yueqing Li, Liudi Zhou, Linna Tong, Li WangAbstract:Freesia hybrida is one of the most famous cut flower variety domesticated from wild species in Freesia genus, distinguished for its colorful flower colors and sweet scents. It has potential to be a model plant to unravel the molecular basis of plant specialized metabolites biosynthesis in family Iridaceae, which are crucial to genetically modify ornamental traits such as flower color and flower scents. However, the lengthy life cycle propagated from tissue culture and extremely low transformation rate severely decelerate functional characterization of genes through transgenic method in this iridaceous plant. Using calluses induced from young flower buds from one popular cultivar of Freesia hybrida, ‘Red River®’, an efficient protoplast isolation method was established and optimized, which was further employed in the gene transient expression system. Results demonstrated that the newly explored transient system was versatile and could be applied in numerous aspects, such as protein immunoblotting, enzyme activity, protein subcellular localization, protein–protein interaction, protein–DNA interaction and regulatory gene transregulation property assays. Moreover, calluses induced from another cultivar of Freesia hybrida, ‘Ambiance’ could also be used to isolate protoplasts for gene transient transfection analysis, indicating the wide applicability of this system. Results in this study provided new methods for the elucidation of gene function in Freesia in vivo, which might also be inspirational in other species with long life cycles or hardly to be transformed, such as plants in family Iridaceae.
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the r2r3 myb factor fhmyb5 from Freesia hybrida contributes to the regulation of anthocyanin and proanthocyanidin biosynthesis
Frontiers in Plant Science, 2019Co-Authors: Yueqing Li, Xiaotong Shan, Liudi Zhou, Song Yang, Shucai Wang, Li WangAbstract:The flavonoids are important and nourishing compounds for plants and human. The transcription regulation of anthocyanin and proanthocyanidin (PA) biosynthesis was extensively studied in dicot compared with monocot plants. In this study, we characterized the functionality of an R2R3-MYB gene FhMYB5 from the monocotyledonous flowering plant of Iridaceae, Freesia hybrida. Multiple sequence aligment and phylogenetic analysis implied that FhMYB5 was clustered into grapevine VvMYB5b subclade. Correlation analysis indicated that the spatio-temporal expression patterns of FhMYB5 coincided well with anthocyanin and PA accumulations in Freesia per se. Furthermore, transient transfection assays in Freesia protoplasts revealed that the late flavonoid biosynthetic genes (e.g., DFR and LDOX) were slightly up-regulated by FhMYB5 alone, whereas both early and late biosynthetic genes were significantly activated when FhMYB5 were co-infected with either of the two IIIf clade bHLH genes, FhTT8L and FhGL3L. Moreover, these results were further confirmed by co-transfection of FhMYB5 with either of the bHLH genes aforementioned into protoplasts expressing GUS reporter gene driven by Freesia promoters. In addition, the overexpression of FhMYB5 in tobacco and Arabidopsis could also significantly up-regulate the expression of genes participating in the general flavonoid pathway. In conclusion, FhMYB5 was proved to function in the general flavonoid pathway in Freesia. The results implied a function conservation of flavonoid biosynthesis related MYB regulators in angiosperm plants.
Dongqin Tang - One of the best experts on this subject based on the ideXlab platform.
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controlled release compound fertilizers improve the growth and flowering of potted Freesia hybrida
Biocatalysis and agricultural biotechnology, 2019Co-Authors: Xi Li, Muhammad Khalid, Dongqin TangAbstract:Abstract The controlled-release fertilizers (CRFs) are the fertilizers which gradually release their mineral nutrients, while at the same time providing proper nutrition to the plants. The CRFs have been widely used to improve crops’ quality and quantity, but have not been applied on Freesia hybrida so far. In this study, Freesia ‘Shangnong Ruxiang’ was used to determine the effect of CRFs on its vegetative and reproductive growth. Two different kinds of commercial CRFs i.e. Osmocote Classic and Agroblen were applied in various doses. In an appropriate dose, Osmocote Classic and Agroblen improved the growth of Freesia. The overall effect of Agroblen is better than Osmocote. Under treatments of 5 g/L Osmocote and 5 g/L or 7 g/L Agroblen, the plant height, scape height, scape number, scape strength, and chlorophyll content were higher than other groups. Under 7 g/L Agroblen, the plants blossomed 10 days earlier than that of control. Taken together, 5 g/L of Osmocote and 5 g/L or 7 g/L of Agroblen are recommended for strong leaf and corm growth with good flowering phenotype, while 5 g/L or 7 g/L of Agroblen only is optimum for early flowering in Freesia.
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de novo sequencing of the Freesia hybrida petal transcriptome to discover putative anthocyanin biosynthetic genes and develop est ssr markers
Acta Physiologiae Plantarum, 2018Co-Authors: Dongqin Tang, Xi LiAbstract:Freesia is an important bulb flower. Based on Illumina platform, the transcriptome profiling of Freesia hybrida ‘Pink Passion’ was conducted by de novo sequencing method in this study. The goal of this study is to reveal basic information and provide data on regulatory mechanism of flower color formation in Freesia. Totally, 49,503,460 short reads, corresponding to total 4.46 GB nucleotides, were yielded. These short reads were then classified into 74,192 unigenes, of which 42,934 were annotated in several databases, including Nr, Nt, Swiss-Prot, KEGG, COG, and GO. A total of 43,594 coding sequences were obtained and 25,409 unigenes were allocated to 128 KEGG pathways. The “metabolic pathways” (6642 counts, 26.14%) were present as the largest category. The Freesia transcriptome results revealed 205 unigenes involved in the flavonoid biosynthesis pathway and 18 unigenes in anthocyanin biosynthesis pathway. Then, 13 genes related to anthocyanin biosynthesis were identified, including 8 up-stream genes and 5 down-stream genes. MISA software identified 10,249 simple sequence repeats (SSR) as putative molecular markers, from which 4996 primer pairs were designed. Then, over 10,249 motifs were identified, and the most common motif was AG/CT (31.18%), followed by A/T and AAG/CTT. One hundred and fifty SSR primer pairs for loci were further synthesized and tested. The primers for 62 SSR loci amplified reproducible amplicons. Thirty-six polymorphic EST–SSR markers were then chosen to screen the polymorphisms among 16 Freesia accessions. The genetic relationships among the 16 accessions were then assessed by the cluster analysis based on these markers. Surprisingly, the 16 Freesia accessions cannot be grouped simply by an individual characteristic, indicating a potential complex genetic relationship of the tested Freesias. In conclusion, this study is the first Freesia transcriptome characterization by large-scale sequencing. The findings provide valuable information for germplasm characterization, genetic diversity and relationship analysis, and marker-assisted breeding in Freesia.
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De novo sequencing of the Freesia hybrida petal transcriptome to discover putative anthocyanin biosynthetic genes and develop EST–SSR markers
Acta Physiologiae Plantarum, 2018Co-Authors: Dongqin Tang, Xi LiAbstract:Freesia is an important bulb flower. Based on Illumina platform, the transcriptome profiling of Freesia hybrida ‘Pink Passion’ was conducted by de novo sequencing method in this study. The goal of this study is to reveal basic information and provide data on regulatory mechanism of flower color formation in Freesia. Totally, 49,503,460 short reads, corresponding to total 4.46 GB nucleotides, were yielded. These short reads were then classified into 74,192 unigenes, of which 42,934 were annotated in several databases, including Nr, Nt, Swiss-Prot, KEGG, COG, and GO. A total of 43,594 coding sequences were obtained and 25,409 unigenes were allocated to 128 KEGG pathways. The “metabolic pathways” (6642 counts, 26.14%) were present as the largest category. The Freesia transcriptome results revealed 205 unigenes involved in the flavonoid biosynthesis pathway and 18 unigenes in anthocyanin biosynthesis pathway. Then, 13 genes related to anthocyanin biosynthesis were identified, including 8 up-stream genes and 5 down-stream genes. MISA software identified 10,249 simple sequence repeats (SSR) as putative molecular markers, from which 4996 primer pairs were designed. Then, over 10,249 motifs were identified, and the most common motif was AG/CT (31.18%), followed by A/T and AAG/CTT. One hundred and fifty SSR primer pairs for loci were further synthesized and tested. The primers for 62 SSR loci amplified reproducible amplicons. Thirty-six polymorphic EST–SSR markers were then chosen to screen the polymorphisms among 16 Freesia accessions. The genetic relationships among the 16 accessions were then assessed by the cluster analysis based on these markers. Surprisingly, the 16 Freesia accessions cannot be grouped simply by an individual characteristic, indicating a potential complex genetic relationship of the tested Freesias. In conclusion, this study is the first Freesia transcriptome characterization by large-scale sequencing. The findings provide valuable information for germplasm characterization, genetic diversity and relationship analysis, and marker-assisted breeding in Freesia.
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hormonal regulation of Freesia cutflowers and fhacs1
Scientia Horticulturae, 2012Co-Authors: Yuan Yuan, Hongmei Qian, Yue Wang, Dongqin TangAbstract:Abstract The differential transcriptional responses of a Freesia 1-aminocyclopropane-l-carboxylate synthase gene ( FhACS1 ) to exogenous ethephon, abscisic acid (ABA), salicylic acid (SA), indole-3-acetic acid (IAA), 6-benzylaminopurine (6-BA), silver thiosulfate (STS) and sugar were studied using real-time quantitative PCR. Pretreatments for periods of 24 h were evaluated in bud 3 and bud 6 on the inflorescence during Freesia flower development and senescence. The results showed that individual exogenous pretreatment with ethephon, IAA, ABA and SA all resulted in the accelerated senescence of Freesia flowers compared to those of control buds. Ethephon enhanced FhACS1 expression and extended this high expression; IAA induced an earlier and higher accumulation of FhACS1 transcripts in bud 3, held-up FhACS1 transcript accumulation in later development in bud 6; ABA evidently stimulated a stronger and earlier response of FhACS1 and SA led a higher and longer FhACS1 transcript accumulation. Conversely, 6-BA, STS and sugar pretreatments had a positive effect on the flower development and downregulated FhACS1 expression. Among these treatments, 6-BA significantly restrained the accumulation of the FhACS1 transcript, especially in bud 6; STS also lowered the FhACS1 transcription level overall; while sugar postponed the arrival of the FhACS1 expression peak and significantly decreased the amount of FhACS1 transcript. These results show that these phytohormones and chemical substances signals lead to transcriptional regulation of FhACS1 , conjecturing that FhACS1 may participate in the complex hormonal and developmental net works in Freesia flower senescence.
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distinct respiration and physiological changes during flower development and senescence in two Freesia cultivars
Hortscience, 2010Co-Authors: Hongmei Qian, Dongqin TangAbstract:Two cultivars of Freesia hybrida, 'Shangnong Jinhuanghou' and 'Shangnong Hongtaige', were used to study the respiration rate and physiological responses during flower development and senescence. Phenotypically, the vase life of 'Shangnong Hongtaige' was significantly shorter than that of 'Shangnong Jinhuanghou'. At the whole flower level, both cultivars displayed similar change patterns on respiration rate. However, the change patterns in tepals, stamens, and pistils showed some differences in the two cultivars. A respiratory climacteric existed in most organs in both cultivars except for the stamen of 'Shangnong Jinhuanghou'. During flower development and senescence, the levels of soluble proteins and soluble sugars were very high at early stages, followed by a dramatic decrease, and the lowest levels occurred in wilted tepals in both cultivars. Superoxide dismutase (SOD) activities increased slightly at early developmental stages followed by a constant decrease in two cultivars, and SOD activities in 'Shangnong Jinhuanghou' were significantly higher than those in 'Shangnong Hongtaige'. Peroxidase activities showed a constant increase before tepals started wilting followed by a decrease in wilted tepals in both cultivars. In both cultivars, electrolytic leakage and malondialdehyde (MDA) content in tepals increased with the progression of development and senescence. MDA content in 'Shangnong Hongtaige' was much higher than that in 'Shangnong Jinhuanghou'. These results indicated that the respiratory climacteric, the decrease of antioxidant enzyme activities, the peroxidation of membrane lipid, and the loss of soluble compounds could be considered as indicators of flower senescence in Freesia.
Anastasios I Darras - One of the best experts on this subject based on the ideXlab platform.
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Acibenzolar-S-methyl and methyl jasmonate treatments of glasshouse-grown Freesias suppress post-harvest petal specking caused by Botrytis cinerea
Journal of Horticultural Science & Biotechnology, 2020Co-Authors: Anastasios I Darras, Daryl C. Joyce, Leon A TerryAbstract:Compounds that activate host plant defence responses potentially offer socio-environmentally sound alternative methods for disease control. In a series of glasshouse trials over 2 years, pre-harvest sprays with acibenzolar-S-methyl (ASM) and methyl jasmonate (MeJA) were tested for suppression of post-harvest infection of cut Freesia hybrida L. flowers by Botrytis cinerea. For the ASM treatments, variability in reducing the incidence of B. cinerea disease was observed between years Freesia varieties, incubation temperatures and ASM concentrations. In the first year, the greatest reductions in lesion numbers on ASM-treated var. 'Cote d'Azur' were recorded using 2.86 mM ASM. For three different post-harvest temperature regimes, the relative reductions in lesion numbers, compared to untreated controls, were 45% at 5 degrees C, 40% at 12 degrees C and 30% at 20 degrees C, respectively. In the second year, lesion numbers were most reduced using 1.43 mM ASM to treat Freesia var. 'Dukaat' flowers. Here, the relative reductions were to 44% at 5 degrees C, 26% at 12 degrees C and 51% at 20 degrees C. MeJA treatments were, in general, more consistently effective than ASM treatments in reducing lesion numbers and lesion diameters on cut Freesia flowers. MeJA-treated (0.2 mM) Freesia flowers (var. 'Dukaat') incubated at 20 degrees C showed relative reductions of 62%, and 45% for lesion number and lesion diameter, respectively. The differing efficacy between ASM and MeJA treatments could be attributed to their differential abilities to induce the salicylic acid (SA)-mediated vs. the jasmonic acid (JA)-mediated host defence pathways, respectively.
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methyl jasmonate and acibenzolar s methyl protect cut Freesia hybrida inflorescences against botrytis cinerea but do not act synergistically
Journal of Horticultural Science & Biotechnology, 2011Co-Authors: Anastasios I Darras, D C Joyce, Leon A TerryAbstract:SummaryMethyl jasmonate (MeJA) and acibenzolar-S-methyl (ASM), two potential elicitors which activate plant defence responses, were tested on inflorescences of Freesia hybrida to suppress petal-specking caused by Botrytis cinerea. Compared to the untreated controls, MeJA applied as a vapour, pulse, or spray to Freesia ‘Cote d’Azur’ inflorescences significantly reduced disease severity scores, lesion numbers, and lesion diameters on attached petals, and lesion diameters in a detached petal bioassay. ASM alone, at 143 µM, provided a degree of protection to Freesia inflorescences by significantly reducing disease severity scores, lesion numbers, and lesion diameters compared to the untreated controls. However, no additive effect was observed for combined treatments with MeJA and ASM. Polyphenol oxidase (PPO) activities in 0.1 µl l–1 MeJA-treated inflorescences, at 24 h and 36 h post-treatment, were 2.7- and 2.0-fold higher, respectively, compared to the untreated controls. In contrast, phenylalanine ammonia-...
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postharvest uv c irradiation on cut Freesia hybrida l inflorescences suppresses petal specking caused by botrytis cinerea
Postharvest Biology and Technology, 2010Co-Authors: Anastasios I Darras, D C Joyce, Leon A TerryAbstract:Postharvest petal specking caused by Botrytis cinerea is a major concern for Freesia growers and sellers in Holland and the UK. Germicidal and inducible host defence effects of UV-C irradiation were evaluated. UV-C irradiation of Freesia inflorescences after artificial inoculation with B. cinerea (i.e. the germicidal effect) was more effective in reducing petal specking, compared to UV-C treatment before artificial inoculation (i.e. the defence induction effect). Cut Freesia inflorescences exposed to 1 kJ m(-2) UV-C after artificial inoculation with 104 B. cinerea conidia mL(-1) displayed reduced disease severity scores, lesion numbers and lesion diameters by 74, 68 and 14%, respectively, compared to non-irradiated control inflorescences. In contrast, UV-C irradiation with I kJ m(-2) before artificial inoculation reduced lesion numbers and lesion diameters by 13 and 24%, compared to the non-irradiated controls. Higher UV-C doses of 2.5 or 5 kJ m(-2) reduced disease severity scores, lesion numbers and lesion diameters when applied after artificial inoculation, but enhanced disease when applied before artificial inoculation. Vase life of cut Freesia inflorescences irradiated with 0.5, 1 or 2.5 kJ m(-2) UV-C was maintained equal to non-irradiated controls. However, 5 kJ m(-2) resulted in phytotoxicity evident as petal discoloration and reduced vase life compared to non-irradiated inflorescences. (C) 2009 Elsevier B.V. All rights reserved.
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Efficacy of postharvest treatments with acibenzolar-S-methyl and methyl jasmonate against Botrytis cinerea infecting cut Freesia hybrida L. flowers
Australasian Plant Pathology, 2007Co-Authors: Anastasios I Darras, Leon A Terry, Daryl C. Joyce, Nektarios E. Pompodakis, Christos I. DimitriadisAbstract:The known plant defence activators acibenzolar-S-methyl (ASM) and methyl jasmonate (MeJA) were applied as spray and as spray or pulse treatments, respectively, after harvest and evaluated for efficacy against Freesia cv. ‘Cote d’Azur’ flower specking disease caused by the pathogen Botrytis cinerea . Lesion numbers on non-inoculated Freesia flowers and lesion diameters on attached petals of inoculated flowers were reduced by 1.43, 2.86 and 5.72mM ASM at 5 and 12°C compared with untreated controls. However, ASM was ineffective in reducing lesion numbers and lesion diameters on non-inoculated and on artificially inoculated flowers incubated at 20?C. ASM showed direct antimicrobial activity in vitro , significantly reducing B. cinerea mycelial growth and conidial germ tube elongation. ASM treatments did not adversely affect the vase life of cut Freesia flowers. MeJA applied as postharvest spray or pulse to Freesia flowers also tended to suppress B. cinerea . MeJA treatments at 12 and 20°C were generally more effective than at 5°C. In contrast to ASM, MeJA usually did not exert direct antimicrobial activity against B. cinerea in vitro . MeJA spray treatment leads to an increase in relative fresh weight and a reduction of wilt scores of flowers during the vase life. In contrast, MeJA pulsing at 0.6mM reduced relative fresh weight and vase life of cut Freesia flowers compared with untreated controls. Overall, the results suggest a potential role for postharvest ASM spray and MeJA spray or pulse treatments in suppressing B. cinerea on cut Freesia flowers. However, variable efficacy needs to be overcome before such plant defence activator treatments could be used in commercial practice.
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postharvest infection of Freesia hybrida flowers by botrytis cinerea
Australasian Plant Pathology, 2006Co-Authors: Anastasios I Darras, D C Joyce, Leon A Terry, I VloutoglouAbstract:‘Specking’ on harvested Freesia (Freesia hybrida) flowers is a problem worldwide. The disease is caused by the fungal pathogen Botrytis cinerea. This disease symptom detracts from appearance and reduces marketability of the flowers. Unlike other important cut flower crops (e.g. gerbera), the mode of infection and epidemiology of postharvest Freesia flower specking caused by B. cinerea has not been reported. Epidemiological studies were carried out under simulated conditions typical of those occurring during postharvest handling of Freesia flowers. Infection of Freesia flowers by B. cinerea occurred when a conidium germinated, formed a germ tube(s) and penetrated epidermal cells. Fungal hyphae then colonised adjacent cells, resulting in visible lesions. Different host reactions were observed on Freesia ‘Cote d’Azur’ petals at 20°C compared to 5°C. The infection process was relatively rapid at 20°C, with visible lesions produced within 7 h of incubation. However, lesion expansion ceased after 24 h of incubation. Infection was slower at 5°C, with visible lesions produced after 48 h of incubation. However, lesion development at 5°C was continuous, with lesions expanding over 4 days. Light microscopy observations revealed increased host defence reactions during infection. These reactions involved production of phenolic compounds, probably lignin and/or callose, around infection sites. Such substances may play a role in restricting petal colonisation and lesion expansion. Disease severity and lesion numbers on Freesia flowers incubated at 12°C were higher, but not significantly higher (P > 0.05), than on those incubated at 20°C. Disease severity and progression were differentially mediated by temperature and relative humidity (R.H.). Infection of Freesia flowers was severe at 100% R.H. for all three incubation temperatures of 5,12 and 20°C. In contrast, no lesions were produced at 80 to 90% R.H. at either 5 or 20°C.
Xi Li - One of the best experts on this subject based on the ideXlab platform.
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controlled release compound fertilizers improve the growth and flowering of potted Freesia hybrida
Biocatalysis and agricultural biotechnology, 2019Co-Authors: Xi Li, Muhammad Khalid, Dongqin TangAbstract:Abstract The controlled-release fertilizers (CRFs) are the fertilizers which gradually release their mineral nutrients, while at the same time providing proper nutrition to the plants. The CRFs have been widely used to improve crops’ quality and quantity, but have not been applied on Freesia hybrida so far. In this study, Freesia ‘Shangnong Ruxiang’ was used to determine the effect of CRFs on its vegetative and reproductive growth. Two different kinds of commercial CRFs i.e. Osmocote Classic and Agroblen were applied in various doses. In an appropriate dose, Osmocote Classic and Agroblen improved the growth of Freesia. The overall effect of Agroblen is better than Osmocote. Under treatments of 5 g/L Osmocote and 5 g/L or 7 g/L Agroblen, the plant height, scape height, scape number, scape strength, and chlorophyll content were higher than other groups. Under 7 g/L Agroblen, the plants blossomed 10 days earlier than that of control. Taken together, 5 g/L of Osmocote and 5 g/L or 7 g/L of Agroblen are recommended for strong leaf and corm growth with good flowering phenotype, while 5 g/L or 7 g/L of Agroblen only is optimum for early flowering in Freesia.
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de novo sequencing of the Freesia hybrida petal transcriptome to discover putative anthocyanin biosynthetic genes and develop est ssr markers
Acta Physiologiae Plantarum, 2018Co-Authors: Dongqin Tang, Xi LiAbstract:Freesia is an important bulb flower. Based on Illumina platform, the transcriptome profiling of Freesia hybrida ‘Pink Passion’ was conducted by de novo sequencing method in this study. The goal of this study is to reveal basic information and provide data on regulatory mechanism of flower color formation in Freesia. Totally, 49,503,460 short reads, corresponding to total 4.46 GB nucleotides, were yielded. These short reads were then classified into 74,192 unigenes, of which 42,934 were annotated in several databases, including Nr, Nt, Swiss-Prot, KEGG, COG, and GO. A total of 43,594 coding sequences were obtained and 25,409 unigenes were allocated to 128 KEGG pathways. The “metabolic pathways” (6642 counts, 26.14%) were present as the largest category. The Freesia transcriptome results revealed 205 unigenes involved in the flavonoid biosynthesis pathway and 18 unigenes in anthocyanin biosynthesis pathway. Then, 13 genes related to anthocyanin biosynthesis were identified, including 8 up-stream genes and 5 down-stream genes. MISA software identified 10,249 simple sequence repeats (SSR) as putative molecular markers, from which 4996 primer pairs were designed. Then, over 10,249 motifs were identified, and the most common motif was AG/CT (31.18%), followed by A/T and AAG/CTT. One hundred and fifty SSR primer pairs for loci were further synthesized and tested. The primers for 62 SSR loci amplified reproducible amplicons. Thirty-six polymorphic EST–SSR markers were then chosen to screen the polymorphisms among 16 Freesia accessions. The genetic relationships among the 16 accessions were then assessed by the cluster analysis based on these markers. Surprisingly, the 16 Freesia accessions cannot be grouped simply by an individual characteristic, indicating a potential complex genetic relationship of the tested Freesias. In conclusion, this study is the first Freesia transcriptome characterization by large-scale sequencing. The findings provide valuable information for germplasm characterization, genetic diversity and relationship analysis, and marker-assisted breeding in Freesia.
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De novo sequencing of the Freesia hybrida petal transcriptome to discover putative anthocyanin biosynthetic genes and develop EST–SSR markers
Acta Physiologiae Plantarum, 2018Co-Authors: Dongqin Tang, Xi LiAbstract:Freesia is an important bulb flower. Based on Illumina platform, the transcriptome profiling of Freesia hybrida ‘Pink Passion’ was conducted by de novo sequencing method in this study. The goal of this study is to reveal basic information and provide data on regulatory mechanism of flower color formation in Freesia. Totally, 49,503,460 short reads, corresponding to total 4.46 GB nucleotides, were yielded. These short reads were then classified into 74,192 unigenes, of which 42,934 were annotated in several databases, including Nr, Nt, Swiss-Prot, KEGG, COG, and GO. A total of 43,594 coding sequences were obtained and 25,409 unigenes were allocated to 128 KEGG pathways. The “metabolic pathways” (6642 counts, 26.14%) were present as the largest category. The Freesia transcriptome results revealed 205 unigenes involved in the flavonoid biosynthesis pathway and 18 unigenes in anthocyanin biosynthesis pathway. Then, 13 genes related to anthocyanin biosynthesis were identified, including 8 up-stream genes and 5 down-stream genes. MISA software identified 10,249 simple sequence repeats (SSR) as putative molecular markers, from which 4996 primer pairs were designed. Then, over 10,249 motifs were identified, and the most common motif was AG/CT (31.18%), followed by A/T and AAG/CTT. One hundred and fifty SSR primer pairs for loci were further synthesized and tested. The primers for 62 SSR loci amplified reproducible amplicons. Thirty-six polymorphic EST–SSR markers were then chosen to screen the polymorphisms among 16 Freesia accessions. The genetic relationships among the 16 accessions were then assessed by the cluster analysis based on these markers. Surprisingly, the 16 Freesia accessions cannot be grouped simply by an individual characteristic, indicating a potential complex genetic relationship of the tested Freesias. In conclusion, this study is the first Freesia transcriptome characterization by large-scale sequencing. The findings provide valuable information for germplasm characterization, genetic diversity and relationship analysis, and marker-assisted breeding in Freesia.
A A Zaidi - One of the best experts on this subject based on the ideXlab platform.
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identification and characterization of bean yellow mosaic virus infecting Freesia
Journal of Plant Biochemistry and Biotechnology, 2009Co-Authors: Yogesh Kumar, Vipin Hallan, A A ZaidiAbstract:Freesia is popularly cultivated in Northern India for its cut flower production. In a survey of Freesia in Northern India, plants under green house cultivation were found to show chlorotic spots on leaves. Samples were collected and the causal agent was identified to be Bean yellow mosaic virus (BYMV), by Enzyme-Linked Immunosorbent Assay (ELISA) and reverse transcription-polymerase chain reaction (RT PCR). Complete coat protein (CP) gene and 3′ UTR sequence of the isolate was determined. The sequence had less than 98 Per cent Nucleotide Identity (PNI). Phylogenetic analysis with other BYMV isolates showed highest similarity with most of the isolates reported from gladiolus, from different countries. The study reveals the molecular characterization of BYMV infecting Freesia for the first time. To the best of our knowledge this is the first report of BYMV infecting Freesia in India.
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first finding of Freesia mosaic virus infecting Freesia in india
Plant Pathology, 2009Co-Authors: Yogesh Kumar, Vipin Hallan, A A ZaidiAbstract:Freesias are popular garden plants in the family Iridaceae. Freesia spp. have been reported to be infected by various viruses: Bean yellow mosaic virus , Freesia mosaic virus , Cucumber mosaic virus , Tobacco rattle virus (Brunt, 1995) and ophioviruses (Vaira et al ., 2006). In April 2007, leaf samples showing chlorotic streaks were collected from Kangra region of Northern India. These samples were tested for the presence of potyviruses using an indirect ELISA kit (Agdia) as per the manufacturer’s instructions. A positive result was obtained from one of the ten collected samples. Total RNA was extracted from this positive leaf sample using RNAqueous® RNA isolation kit (Ambion). RT-PCR was performed with a degenerate potyvirus primer pair (P9502 & CPUP), which amplifies the partial coat protein (CP) gene and 3 ′ -UTR region of the viral genome (Van der Vlugt et al ., 1999). An amplicon of ~650 bp was obtained, which was cloned into pGEM®-T Easy vector (Promega) and sequenced. Analysis showed that the sequence shared 98% identity with the only sequence of the tentativelynamed Spiranthes mosaic virus 2 (SpMV2; GenBank Accession No. AY685219), reported from Spiranthes cernua in USA (Guaragna et al ., 2006). In order to sequence the full CP gene, primers were designed using the available SpMV2 sequence. The complete CP gene and 3 ′ -UTR was amplified, cloned and sequenced. A sequence of 1026 bp was submitted to the EMBL Database (Accession No. AM748701). This sequence showed 97% identity with a partial sequence (429 bp) of Freesia mosaic virus (FreMV; EF203688) obtained from a Dutch Freesia isolate, this short sequence is the only one available for FreMV. The Indian isolate showed less than 86% homology at the amino acid level with any other potyvirus. A host range study using the Indian isolate was carried out using Freesia and Spiranthes spp. The isolate could not be transmitted to the orchid; but it did infect Freesia , showing mild chlorotic symptoms, typical of FreMV infection. Based on the biological and sequence data, the present isolate has been identified as FreMV. This study also supports the case that SpMV2 is in fact an isolate/strain of FreMV, rather than being a distinct virus. This is the first report of FreMV in India.
