Silencing of FOREVER YOUNG FLOWER-Like Genes from Phalaenopsis Orchids Promotes Flower Senescence and Abscission

2020 ◽  
Author(s):  
Wei-Han Chen ◽  
Zhi-Yi Jiang ◽  
Hsing-Fun Hsu ◽  
Chang-Hsien Yang
Keyword(s):  
Transgenic Arabidopsis ◽  
Ectopic Expression ◽  
Flower Senescence ◽  
Strongly Correlated ◽  
Ethylene Signaling ◽  
Virus Induced Gene Silencing ◽  
Flower Organs ◽  
Flower Evolution ◽  
Early Flower ◽  
Early Occurrence

Abstract Ectopic expression of FOREVER YOUNG FLOWER (FYF) delays floral senescence and abscission in transgenic Arabidopsis. To analyze the FYF function in Phalaenopsis orchids, two FYF-like genes (PaFYF1/2) were identified. PaFYF1/2 were highly expressed in young Phalaenopsis flowers, and their expression decreased significantly afterward until flower senescence. This pattern was strongly correlated with the process of flower senescence and revealed that PaFYF1/2 function to suppress senescence/abscission during early flower development. Interestingly, in flowers, PaFYF1 was consistently expressed less in petals than in lips/sepals, whereas PaFYF2 was expressed relatively evenly in all flower organs. This difference suggests a regulatory modification of the functions of PaFYF1 and PaFYF2 during Phalaenopsis flower evolution. Delayed flower senescence and abscission, which were unaffected by ethylene treatment, were observed in 35S::PaFYF1/2 and 35S::PaFYF1/2 + SRDX transgenic Arabidopsis plants due to the downregulation of the ethylene signaling and abscission-associated genes EDF1-4, IDA and BOP1/2. These results suggest a possible repressor role for Phalaenopsis PaFYF1/2 in controlling floral senescence/abscission by suppressing ethylene signaling and abscission-associated genes. To further validate the function of PaFYF1/2, PaFYF1/2-VIGS (virus-induced gene silencing) Phalaenopsis were generated and analyzed. Promotion of senescence and abscission was observed in PaFYF1/2-VIGS Phalaenopsis flowers by the upregulation of PeEDF1/2, PeSAG39 and PeBOP1/2 expression, the early occurrence of greening according to their increased chlorophyll content and the reduction in water content in flower organs. Our results support that PaFYF1/2 function as transcriptional repressors to prohibit flower senescence and abscission in Phalaenopsis.

scholarly journals Characterization of Two AGL6–Like Genes from a Chinese Endemic Woody Tree, Manglietia patungensis (Magnoliaceae) Provides Insight into Perianth Development and Evolution in Basal Angiosperms

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 669 ◽  
Author(s):  
Zhixiong Liu ◽  
Kebin Zhang ◽  
Laiyun Li ◽  
Yue Fei ◽  
Faju Chen
Keyword(s):  
Transgenic Plants ◽  
Phylogenetic Analyses ◽  
Ectopic Expression ◽  
Basal Angiosperms ◽  
Phenotypic Changes ◽  
Flower Evolution ◽  
Early Flower ◽  
Insight Into ◽  
Development And Evolution

Manglietia patungensis (Magnoliaceae) exhibits radially symmetric flowers with perianth consisting of three separate sepaloid tepals in whorl 1 and six petaloid tepals in the inner two whorls, which shows an obvious difference from flowers of most Magnoliaceae species that contain three uniform petaloid tepals whorls, and make it an excellent model for understanding perianth morphology differentiation during early flower evolution. Here, two AGL6 orthologs, MapaAGL6-1 and MapaAGL6-2, were isolated from M. patungensis. Sequence alignment and phylogenetic analyses grouped both genes into the AGL6 lineage. MapaAGL6-1 is expressed only in the perianth whorls, while MapaAGL6-2 is strongly expressed in the perianth whorls but is lowly expressed in gynoecium. Furthermore, ectopic expression of MapaAGL6-1 results in strong complementation phenotypes in the Arabidopsis ap1-10 flower and production of normal floral organs in four floral whorls only with the petal number reduced in whorl 2, while ectopic expression of MapaAGL6-2 only results in petals partly rescued but failing to terminate carpelloid development in Arabidopsis ap1-10 mutant. In addition, the daughter lines generated from a cross between 35S::MapaAGL6-1 transgenic plants showing strong phenotypes and 35S::MapaAGL6-2 transgenic plants showing phenotypic changes produce normal flowers. Our results suggest that MapaAGL6-1 is a reasonable A-function gene controlling perianth identity in Magnoliaceae, which infers from its expression region and complementation phenotypes in Arabidopsis ap1 mutant, while MapaAGL6-2 is mainly involved in petaloid tepal development. Our data also provide a new clue to uncover the perianth development and early evolution in basal angiosperms.

scholarly journals Ectopic expression of citrus UDP-GLUCOSYL TRANSFERASE gene enhances anthocyanin and proanthocyanidins contents and confers high light tolerance in Arabidopsis

2019 ◽  
Author(s):  
Muhammad Junaid Rao ◽  
Yuantao Xu ◽  
Yue Huang ◽  
Xiaomei Tang ◽  
Xiuxin Deng ◽  
...  
Keyword(s):  
Transgenic Arabidopsis ◽  
Light Stress ◽  
Ectopic Expression ◽  
Underlying Mechanism ◽  
High Light ◽  
High Accumulation ◽  
Total Anthocyanin ◽  
High Light Stress ◽  
Transferase Gene ◽  
Dietary Flavonoids

Abstract Background Citrus fruits are consumed freshly or as juice to directly provide various dietary flavonoids to humans. Diverse metabolites at different levels are present among Citrus genera and many flavonoids biosynthetic genes were induced after abiotic stresses. To better understand the underlying mechanism, we designed experiments to overexpress a UDP-GLUCOSYL TRANSFERASE gene from Citrus sinensis (sweet orange) to evaluate its possible function in metabolism and response to stress.Results Our results demonstrated that overexpression of Cs-UGT78D3 resulted in high accumulation of proanthocyanidins in the seed coat and a dark brown color to transgenic Arabidopsis seeds. In addition, the total contents of flavonoid and anthocyanin were significantly enhanced in the leaves of overexpressed lines. Gene expression analyses indicated that many flavonoid (flavonol) and anthocyanin genes were up-regulated by 4-15 folds in transgenic Arabidopsis. Moreover, after 14 days of high light stress treatment, the transgenic Arabidopsis lines showed strong antioxidant activity and higher total contents of anthocyanins and flavonoids in leaves compared with the wild type.Conclusion Our study concluded that the citrus Cs-UGT78D3 gene is involved in proanthocyanidins accumulation in seed coats and confers tolerance to high light stress by accumulating the total anthocyanin and flavonoid contents with better antioxidant potential (due to photoprotective activity of anthocyanin) in the transgenic Arabidopsis.

scholarly journals Molecular Cloning, Characterization and Expression of SUPPRESSOR of OVEREXPRESSION of CONSTANS 1 (NnSOC1) and NnSOC1-like in Nelumbo nucifera

2021 ◽  
Vol 25 (04) ◽  
pp. 851-858
Author(s):  
Chen Dong
Keyword(s):  
Molecular Mechanism ◽  
Fruit Set ◽  
Transgenic Arabidopsis ◽  
Mrna Level ◽  
Ectopic Expression ◽  
Nelumbo Nucifera ◽  
Mads Box Genes ◽  
Flowering Stage ◽  
Fundamental Research ◽  
Initiation Stage

For the aim of unveiling the molecular mechanism of flowering, the MADS-box genes of SUPPRESSOR of OVEREXPRESSION of CONSTANS 1 (NnSOC1) and NnSOC1-like were isolated in Nelumbo nucifera. Seven introns splicing of NnSOC1 and NnSOC1-like strictly followed the GT-AG rule, consisting of all the characteristic motifs of SOC1 family. NnSOC1 and NnSOC1-like were widely distributed in reproductive and vegetative tissues of N. nucifera, exhibiting the highest expression in leaves and the lowest level in embryo. Additionally, both genes were expressed in the whole flowering stage, with the highest mRNA level observed in the initiation stage of flowering and the lowest expression in fruit set. Ectopic expression of NnSOC1 and NnSOC1-like advanced the flowering time of transgenic Arabidopsis, and decreased the rosetta leaves production. These results suggested that NnSOC1 and NnSOC1-like were involved in initiation of flowering, which are likely to serve as fundamental research for studying molecular mechanism of flowering in aquatic plants. © 2021 Friends Science Publishers

scholarly journals Ectopic expression of citrus UDP-GLUCOSYL TRANSFERASE gene enhances anthocyanin and proanthocyanidins contents and confers high light tolerance in Arabidopsis

2019 ◽  
Author(s):  
Muhammad Junaid Rao ◽  
Yuantao Xu ◽  
Yue Huang ◽  
Xiaomei Tang ◽  
Xiuxin Deng ◽  
...  
Keyword(s):  
Transgenic Arabidopsis ◽  
Light Stress ◽  
Ectopic Expression ◽  
Underlying Mechanism ◽  
High Light ◽  
High Accumulation ◽  
Total Anthocyanin ◽  
High Light Stress ◽  
Transferase Gene ◽  
Dietary Flavonoids

Abstract Background Citrus fruits are consumed freshly or as juice to directly provide various dietary flavonoids to humans. Diverse metabolites at different levels are present among Citrus genera and many flavonoids biosynthetic genes were induced after abiotic stresses. To better understand the underlying mechanism, we designed experiments to overexpress a UDP-GLUCOSYL TRANSFERASE gene from Citrus sinensis (sweet orange) to evaluate its possible function in metabolism and response to stress.Results Our results demonstrated that overexpression of Cs-UGT78D3 resulted in high accumulation of proanthocyanidins in the seed coat and a dark brown color to transgenic Arabidopsis seeds. In addition, the total contents of flavonoid and anthocyanin were significantly enhanced in the leaves of overexpressed lines. Gene expression analyses indicated that many flavonoid (flavonol) and anthocyanin genes were up-regulated by 4-15 folds in transgenic Arabidopsis. Moreover, after 14 days of high light stress treatment, the transgenic Arabidopsis lines showed strong antioxidant activity and higher total contents of anthocyanins and flavonoids in leaves compared with the wild type.Conclusion Our study concluded that the citrus Cs-UGT78D3 gene is involved in proanthocyanidins accumulation in seed coats and confers tolerance to high light stress by accumulating the total anthocyanin and flavonoid contents with better antioxidant potential (due to photoprotective activity of anthocyanin) in the transgenic Arabidopsis.

scholarly journals Transcription Factor AtMYB44 Regulates Induced Expression of the ETHYLENE INSENSITIVE2 Gene in Arabidopsis Responding to a Harpin Protein

2011 ◽  
Vol 24 (3) ◽  
pp. 377-389 ◽  
Author(s):  
Ruoxue Liu ◽  
Lei Chen ◽  
Zhenhua Jia ◽  
Beibei Lü ◽  
Haojie Shi ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transgenic Arabidopsis ◽  
Defense Responses ◽  
Binding Activity ◽  
Ethylene Signaling ◽  
Wild Type ◽  
Induced Expression ◽  
Harpin Protein ◽  
Ethylene Signaling Pathway ◽  
Bacterial Plant Pathogen

AtMYB44 is a transcription factor that functions in association with the ethylene-signaling pathway in Arabidopsis thaliana. The pathway depends on ETHYLENE INSENSITIVE2 (EIN2), an essential component of ethylene signaling, to regulate defense responses in the plant following treatment with HrpNEa, a harpin protein from a bacterial plant pathogen. Here, we show that AtMYB44 regulates induced expression of the EIN2 gene in HrpNEa-treated Arabidopsis plants. A HrpNEa and ethylene–responsive fragment of the AtMYB44 promoter is sufficient to support coordinate expression of AtMYB44 and EIN2 in specific transgenic Arabidopsis. In the plant, the AtMYB44 protein localizes to nuclei and binds the EIN2 promoter; the HrpNEa treatment promotes AtMYB44 production, binding activity, and transcription of AtMYB44 and EIN2. AtMYB44 overexpression results in increased production of the AtMYB44 protein and the occurrence of AtMYB44-EIN2 interaction under all genetic backgrounds of wild-type Arabidopsis and the etr1-1, ein2-1, ein3-1, and ein5-1 mutants, which have defects in the ethylene receptor ETR1 and the signal regulators EIN2, EIN3, and EIN5. However, AtMYB44 overexpression leads to enhanced EIN2 expression only under backgrounds of wild type, ein3-1, and ein5-1 but not etr1-1 and ein2-1, suggesting that ethylene perception is necessary to the regulation of EIN2 transcription by AtMYB44.

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