RNAi-mediated repression of dormancy-related genes results in evergrowing apple trees

2021 ◽  
Author(s):  
Rongmei Wu ◽  
Janine Cooney ◽  
Sumathi Tomes ◽  
Ria Rebstock ◽  
Sakuntala Karunairetnam ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Bud Dormancy ◽  
Precocious Flowering ◽  
Coding Regions ◽  
Pathway Gene ◽  
Elevated Expression ◽  
Transgenic Lines ◽  
Terminal Buds ◽  
Normal Flower

Abstract DORMANCY ASSOCIATED MADS-box (DAM) and SHORT VEGETATIVE PHASE (SVP) genes have been implicated in the regulation of winter dormancy in perennials. Ectopic expression of apple (Malus ×domestica ‘Royal Gala’) DAM and SVP genes delays budbreak and constrains lateral shoot outgrowth. In this study, we used RNAi interference (RNAi) to simultaneously target all apple DAM and SVP genes to study their role and mode of action in the regulation of bud dormancy, budbreak and flowering. A synthetic construct carrying a hairpin fragment assembled from sequences specific to coding regions of three DAM and two SVP genes was used to generate transgenic lines. Reduced expression of DAM/SVP genes resulted in delayed leaf senescence and abscission in autumn, failure to enter bud dormancy in winter, and continual growth of new leaves regardless of the season for over 3 years. Precocious flowering but normal flower morphology, fertility and fruit development were observed. The non-dormant phenotype was associated with modified phytohormone composition. The content of gibberellins (GAs) and jasmonates (JAs) was significantly increased in terminal buds of RNAi lines compared to wildtype plants, accompanied by elevated expression of the key GA biosynthesis pathway gene GIBBERELLIN 20 OXIDASE-2 (MdGA20ox-2) along with the FLOWERING LOCUS T gene MdFT2. The key mediator of plasmodesmatal closure, MdCALLOSE SYNTHASE 1 (MdCALS1) was repressed in RNAi lines. This study provides functional evidence for the role of DAM/SVP genes in vegetative phenology of apple, and paves the way for production of low-chill varieties suitable for growth in warming climates.

scholarly journals The vascular targeted citrus FLOWERING LOCUS T3 gene promotes non-inductive early flowering in transgenic Carrizo rootstocks and grafted juvenile scions

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juliana M. Soares ◽  
Kyle C. Weber ◽  
Wenming Qiu ◽  
Daniel Stanton ◽  
Lamiaa M. Mahmoud ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Transcriptome Profiling ◽  
Early Flowering ◽  
Ethylene Response Factor ◽  
Precocious Flowering ◽  
Carrizo Citrange ◽  
Transgenic Lines ◽  
Improvement Programs ◽  
Flowering Locus ◽  
Two Populations

AbstractShortening the juvenile stage in citrus and inducing early flowering has been the focus of several citrus genetic improvement programs. FLOWERING LOCUS T (FT) is a small phloem-translocated protein that regulates precocious flowering. In this study, two populations of transgenic Carrizo citrange rootstocks expressing either Citrus clementina FT1 or FT3 genes under the control of the Arabidopsis thaliana phloem specific SUCROSE SYNTHASE 2 (AtSUC2) promoter were developed. The transgenic plants were morphologically similar to the non-transgenic controls (non-transgenic Carrizo citrange), however, only AtSUC2-CcFT3 was capable of inducing precocious flowers. The transgenic lines produced flowers 16 months after transformation and flower buds appeared 30–40 days on juvenile immature scions grafted onto transgenic rootstock. Gene expression analysis revealed that the expression of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) and APETALA1 (AP1) were enhanced in the transgenics. Transcriptome profiling of a selected transgenic line showed the induction of genes in different groups including: genes from the flowering induction pathway, APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) family genes, and jasmonic acid (JA) pathway genes. Altogether, our results suggested that ectopic expression of CcFT3 in phloem tissues of Carrizo citrange triggered the expression of several genes to mediate early flowering.

scholarly journals Ectopic Expression of Fiber Related Gbwri1 Complements Seed Phenotype in Arabidopsis thaliana

2021 ◽  
Vol 25 (01) ◽  
pp. 123-130
Author(s):  
Mahnoor Imran
Keyword(s):  
Arabidopsis Thaliana ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Ectopic Expression ◽  
Acid Biosynthesis ◽  
Functional Homology ◽  
Normal Seedling ◽  
Transgenic Lines ◽  
Protein Isoform

WRINKLED1 belongs to AP2/EREB family of transcription factors whose role has been well established in seed oil biosynthesis. The objective of the study was to trace the role of fiber related Gbwri1 in seed development and fatty acid biosynthesis. In this study, we isolated a transcript from elite fiber producing cotton (Gossypium barbadense), which is over-expressed in G. barbadense fibers as compared to G. hirsutum and G. arboreum. The putative protein encoded by this transcript exhibited homology in specific domains and protein structure with WRINKLED1 of Arabidopsis thaliana and was thus designated as Gbwri1. In this study, we investigated the functional homology of fiber elongation related Gbwri1 with fatty acid biosynthesis regulator Atwri1. Ectopic expression of Gbwri1 in wri1-3 mutant of A. thaliana was analyzed. In the transgenic lines of A. thaliana, Gbwri1 resumed the seed weight, seed area, and surface morphology to the wild type. Gbwri1 transformation rescued the wrinkled phenotype of wri1-3 mutants by resuming the expression of fatty acid biosynthesis genes biotin carboxyl carrier protein isoform 2 (bccp2) and keto-ACP synthase 1 (kas1). Moreover, the seedling development of transgenic lines on non-sucrose medium demonstrated that the Gbwri1 was able to regulate the supply of sucrose for normal seedling establishment. Our results showed that the transformation of Gbwri1 in A. thaliana wri1-3 mutant was able to complement wri1-3 impaired phenotype. Thus, Gbwri1 is involved in cotton fiber development and fatty acid biosynthesis in seeds. © 2021 Friends Science Publishers

scholarly journals Florigen governs shoot regeneration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yaarit Kutsher ◽  
Michal Fisler ◽  
Adi Faigenboim ◽  
Moshe Reuveni
Keyword(s):  
Nitric Oxide ◽  
Shoot Regeneration ◽  
Ectopic Expression ◽  
Flowering Plants ◽  
Regeneration Capacity ◽  
No Donor ◽  
Tobacco Leaves ◽  
Age Related ◽  
Delayed Flowering

AbstractIt is widely known that during the reproductive stage (flowering), plants do not root well. Most protocols of shoot regeneration in plants utilize juvenile tissue. Adding these two realities together encouraged us to study the role of florigen in shoot regeneration. Mature tobacco tissue that expresses the endogenous tobacco florigen mRNA regenerates poorly, while juvenile tissue that does not express the florigen regenerates shoots well. Inhibition of Nitric Oxide (NO) synthesis reduced shoot regeneration as well as promoted flowering and increased tobacco florigen level. In contrast, the addition of NO (by way of NO donor) to the tissue increased regeneration, delayed flowering, reduced tobacco florigen mRNA. Ectopic expression of florigen genes in tobacco or tomato decreased regeneration capacity significantly. Overexpression pear PcFT2 gene increased regeneration capacity. During regeneration, florigen mRNA was not changed. We conclude that florigen presence in mature tobacco leaves reduces roots and shoots regeneration and is the possible reason for the age-related decrease in regeneration capacity.

scholarly journals Telomeric and Sub-Telomeric Structure and Implications in Fungal Opportunistic Pathogens

2021 ◽  
Vol 9 (7) ◽  
pp. 1405
Author(s):  
Raffaella Diotti ◽  
Michelle Esposito ◽  
Chang Hui Shen
Keyword(s):  
Fungal Pathogens ◽  
Functional Abilities ◽  
Opportunistic Pathogens ◽  
Telomeric Sequences ◽  
Coding Regions ◽  
Telomeric Structure ◽  
Linear Chromosomes ◽  
Dna Ends ◽  
Telomere Structure

Telomeres are long non-coding regions found at the ends of eukaryotic linear chromosomes. Although they have traditionally been associated with the protection of linear DNA ends to avoid gene losses during each round of DNA replication, recent studies have demonstrated that the role of these sequences and their adjacent regions go beyond just protecting chromosomal ends. Regions nearby to telomeric sequences have now been identified as having increased variability in the form of duplications and rearrangements that result in new functional abilities and biodiversity. Furthermore, unique fungal telomeric and chromatin structures have now extended clinical capabilities and understanding of pathogenicity levels. In this review, telomere structure, as well as functional implications, will be examined in opportunistic fungal pathogens, including Aspergillus fumigatus, Candida albicans, Candida glabrata, and Pneumocystis jirovecii.

scholarly journals Transcriptomic and genetic approaches reveal an essential role of the NAC transcription factor SlNAP1 in the growth and defense response of tomato

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiao Wang ◽  
Chenfei Zheng ◽  
Xiangqi Shao ◽  
Zhangjian Hu ◽  
Jianxin Li ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Defense Response ◽  
Global Climate ◽  
Plant Responses ◽  
Multiple Stresses ◽  
Bacterial Diseases ◽  
Bacterial Wilt Disease ◽  
Transgenic Lines ◽  
Breeding Target

AbstractWith global climate change, plants are frequently being exposed to various stresses, such as pathogen attack, drought, and extreme temperatures. Transcription factors (TFs) play crucial roles in numerous plant biological processes; however, the functions of many tomato (Solanum lycopersicum L.) TFs that regulate plant responses to multiple stresses are largely unknown. Here, using an RNA-seq approach, we identified SlNAP1, a NAC TF-encoding gene, which was strongly induced by various stresses. By generating SlNAP1 transgenic lines and evaluating their responses to biotic and abiotic stresses in tomato, we found that SlNAP1-overexpressing plants showed significantly enhanced defense against two widespread bacterial diseases, leaf speck disease, caused by Pseudomonas syringae pv. tomato (Pst) DC3000, and root-borne bacterial wilt disease, caused by Ralstonia solanacearum. In addition, SlNAP1 overexpression dramatically improved drought tolerance in tomato. Although the SlNAP1-overexpressing plants were shorter than the wild-type plants during the early vegetative stage, eventually, their fruit yield increased by 10.7%. Analysis of different hormone contents revealed a reduced level of physiologically active gibberellins (GAs) and an increased level of salicylic acid (SA) and abscisic acid (ABA) in the SlNAP1-overexpressing plants. Moreover, EMSAs and ChIP-qPCR assays showed that SlNAP1 directly activated the transcription of multiple genes involved in GA deactivation and both SA and ABA biosynthesis. Our findings reveal that SlNAP1 is a positive regulator of the tomato defense response against multiple stresses and thus may be a potential breeding target for improving crop yield and stress resistance.

scholarly journals Identification of Autosomal Regions Involved in Drosophila Raf Function

Genetics ◽  
2000 ◽  
Vol 156 (2) ◽  
pp. 763-774 ◽  
Author(s):  
Willis Li ◽  
Elizabeth Noll ◽  
Norbert Perrimon
Keyword(s):  
Limb Development ◽  
Target Gene ◽  
Biological Function ◽  
Genetic Interaction ◽  
Ectopic Expression ◽  
Tor Signaling ◽  
Downstream Effector ◽  
Early Embryos ◽  
Genomic Regions

Abstract Raf is an essential downstream effector of activated p21Ras (Ras) in transducing proliferation or differentiation signals. Following binding to Ras, Raf is translocated to the plasma membrane, where it is activated by a yet unidentified “Raf activator.” In an attempt to identify the Raf activator or additional molecules involved in the Raf signaling pathway, we conducted a genetic screen to identify genomic regions that are required for the biological function of Drosophila Raf (Draf). We tested a collection of chromosomal deficiencies representing ∼70% of the autosomal euchromatic genomic regions for their abilities to enhance the lethality associated with a hypomorphic viable allele of Draf, DrafSu2. Of the 148 autosomal deficiencies tested, 23 behaved as dominant enhancers of Draf  Su2, causing lethality in Draf  Su2 hemizygous males. Four of these deficiencies identified genes known to be involved in the Drosophila Ras/Raf (Ras1/Draf) pathway: Ras1, rolled (rl, encoding a MAPK), 14-3-3ϵ, and bowel (bowl). Two additional deficiencies removed the Drosophila Tec and Src homologs, Tec29A and Src64B. We demonstrate that Src64B interacts genetically with Draf and that an activated form of Src64B, when overexpressed in early embryos, causes ectopic expression of the Torso (Tor) receptor tyrosine kinase-target gene tailless. In addition, we show that a mutation in Tec29A partially suppresses a gain-of-function mutation in tor. These results suggest that Tec29A and Src64B are involved in Tor signaling, raising the possibility that they function to activate Draf. Finally, we discovered a genetic interaction between Draf  Su2 and Df(3L)vin5 that revealed a novel role of Draf in limb development. We find that loss of Draf activity causes limb defects, including pattern duplications, consistent with a role for Draf in regulation of engrailed (en) expression in imaginal discs.

GRAS-domain transcription factor PAT1 regulates jasmonic acid biosynthesis in grape cold stress response

2021 ◽  
Author(s):  
Zemin Wang ◽  
Darren Chern Jan Wong ◽  
Yi Wang ◽  
Guangzhao Xu ◽  
Chong Ren ◽  
...  
Keyword(s):  
Stress Response ◽  
Cold Stress ◽  
Cold Tolerance ◽  
Cold Treatment ◽  
Ectopic Expression ◽  
Bimolecular Fluorescence Complementation ◽  
Luciferase Reporter ◽  
Vitis Amurensis ◽  
Mobility Shift

Abstract Cultivated grapevine (Vitis) is a highly valued horticultural crop, and cold stress affects its growth and productivity. Wild Amur grape (Vitis amurensis) PAT1 (Phytochrome A signal transduction 1, VaPAT1) is induced by low temperature, and ectopic expression of VaPAT1 enhances cold tolerance in Arabidopsis (Arabidopsis thaliana). However, little is known about the molecular mechanism of VaPAT1 during the cold stress response in grapevine. Here, we confirmed the overexpression of VaPAT1 in transformed grape calli enhanced cold tolerance. Yeast two-hybrid and bimolecular fluorescence complementation assays highlighted an interaction between VaPAT1 with INDETERMINATE-DOMAIN 3 (VaIDD3). A role of VaIDD3 in cold tolerance was also indicated. Transcriptome analysis revealed VaPAT1 and VaIDD3 overexpression and cold treatment coordinately modulate the expression of stress-related genes including lipoxygenase 3 (LOX3), a gene encoding a key jasmonate biosynthesis enzyme. Co-expression network analysis indicated LOX3 might be a downstream target of VaPAT1. Both electrophoretic mobility shift and dual luciferase reporter assays showed the VaPAT1-IDD3 complex binds to the IDD-box (AGACAAA) in the VaLOX3 promoter to activate its expression. Overexpression of both VaPAT1 and VaIDD3 increased the transcription of VaLOX3 and JA levels in transgenic grape calli. Conversely, VaPAT1-SRDX (dominant repression) and CRISPR/Cas9-mediated mutagenesis of PAT1-ED causing the loss of the C-terminus in grape calli dramatically prohibited the accumulation of VaLOX3 and JA levels during cold treatment. Together, these findings point to a pivotal role of VaPAT1 in the cold stress response in grape by regulating JA biosynthesis.

Differential regulation of granulopoiesis by the basic helix-loop-helix transcriptional inhibitors Id1 and Id2

Blood ◽  
2005 ◽  
Vol 105 (11) ◽  
pp. 4272-4281 ◽  
Author(s):  
Miranda Buitenhuis ◽  
Hanneke W. M. van Deutekom ◽  
Liesbeth P. Verhagen ◽  
Anders Castor ◽  
Sten Eirik W. Jacobsen ◽  
...  
Keyword(s):  
Critical Role ◽  
Ectopic Expression ◽  
Constitutive Expression ◽  
Retroviral Transduction ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Cd34 Cells ◽  
Final Maturation ◽  
Inhibitor Of Dna Binding

Abstract Inhibitor of DNA binding (Id) proteins function as inhibitors of members of the basic helix-loop-helix family of transcription factors and have been demonstrated to play an important role in regulating lymphopoiesis. However, the role of these proteins in regulation of myelopoiesis is currently unclear. In this study, we have investigated the role of Id1 and Id2 in the regulation of granulopoiesis. Id1 expression was initially up-regulated during early granulopoiesis, which was then followed by a decrease in expression during final maturation. In contrast, Id2 expression was up-regulated in terminally differentiated granulocytes. In order to determine whether Id expression plays a critical role in regulating granulopoiesis, Id1 and Id2 were ectopically expressed in CD34+ cells by retroviral transduction. Our experiments demonstrate that constitutive expression of Id1 inhibits eosinophil development, whereas in contrast neutrophil differentiation was modestly enhanced. Constitutive Id2 expression accelerates final maturation of both eosinophils and neutrophils, whereas inhibition of Id2 expression blocks differentiation of both lineages. Transplantation of β2-microglobulin-/- nonobese diabetic severe combined immunodeficient (NOD/SCID) mice with CD34+ cells ectopically expressing Id1 resulted in enhanced neutrophil development, whereas ectopic expression of Id2 induced both eosinophil and neutrophil development. These data demonstrate that both Id1 and Id2 play a critical, although differential role in granulopoiesis.

Over-expression of the rice OsAMT1-1 gene increases ammonium uptake and content, but impairs growth and development of plants under high ammonium nutrition

2006 ◽  
Vol 33 (2) ◽  
pp. 153 ◽  
Author(s):  
Mohammad S. Hoque ◽  
Josette Masle ◽  
Michael K. Udvardi ◽  
Peter R. Ryan ◽  
Narayana M. Upadhyaya
Keyword(s):  
Transgenic Plants ◽  
Ammonium Assimilation ◽  
Ammonium Transporter ◽  
Ammonium Uptake ◽  
Vegetative Stage ◽  
Over Expression ◽  
Transgenic Lines ◽  
Ammonium Nutrition ◽  
Maize Ubiquitin Promoter

A transgenic approach was undertaken to investigate the role of a rice ammonium transporter (OsAMT1-1) in ammonium uptake and consequent ammonium assimilation under different nitrogen regimes. Transgenic lines overexpressing OsAMT1-1 were produced by Agrobacterium-mediated transformation of two rice cultivars, Taipei 309 and Jarrah, with an OsAMT1-1 cDNA gene construct driven by the maize ubiquitin promoter. Transcript levels of OsAMT1-1 in both Taipei 309 and Jarrah transgenic lines correlated positively with transgene copy number. Shoot and root biomass of some transgenic lines decreased during seedling and early vegetative stage compared to the wild type, especially when grown under high (2 mm) ammonium nutrition. Transgenic plants, particularly those of cv. Jarrah recovered in the mid-vegetative stage under high ammonium nutrition. Roots of the transgenic plants showed increased ammonium uptake and ammonium content. We conclude that the decreased biomass of the transgenic lines at early stages of growth might be caused by the accumulation of ammonium in the roots owing to the inability of ammonium assimilation to match the greater ammonium uptake.

scholarly journals Potential role of senescent macrophages in radiation-induced pulmonary fibrosis

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Lulu Su ◽  
Yinping Dong ◽  
Yueying Wang ◽  
Yuquan Wang ◽  
Bowen Guan ◽  
...  
Keyword(s):  
Matrix Metalloproteinases ◽  
Pulmonary Fibrosis ◽  
Late Toxicity ◽  
Airway Epithelial ◽  
Tnf Α ◽  
Elevated Expression ◽  
Radiation Induced ◽  
Therapeutic Radiation ◽  
Tgf Β1

AbstractRadiation-induced pulmonary fibrosis (RIPF) is a late toxicity of therapeutic radiation in clinic with poor prognosis and limited therapeutic options. Previous results have shown that senescent cells, such as fibroblast and type II airway epithelial cell, are strongly implicated in pathology of RIPF. However, the role of senescent macrophages in the development RIPF is still unknown. In this study, we report that ionizing radiation (IR) increase cellular senescence with higher expression of senescence-associated β-galactosidase (SA-β-Gal) and senescence-specific genes (p16, p21, Bcl-2, and Bcl-xl) in irradiated bone marrow-derived monocytes/macrophages (BMMs). Besides, there’s a significant increase in the expression of pro-fibrogenic factors (TGF-β1 and Arg-1), senescence-associated secretory phenotype (SASP) proinflammatory factors (Il-1α, Il-6, and Tnf-α), SASP chemokines (Ccl2, Cxcl10, and Ccl17), and SASP matrix metalloproteinases (Mmp2, Mmp9 and Mmp12) in BMMs exposed to 10 Gy IR. In addition, the percentages of SA-β-Gal+ senescent macrophages are significantly increased in the macrophages of murine irradiated lung tissue. Moreover, robustly elevated expression of p16, SASP chemokines (Ccl2, Cxcl10, and Ccl17) and SASP matrix metalloproteinases (Mmp2, Mmp9, and Mmp12) is observed in the macrophages of irradiated lung, which might stimulate a fibrotic phenotype in pulmonary fibroblasts. In summary, irradiation can induce macrophage senescence, and increase the secretion of SASP in senescent macrophages. Our findings provide important evidence that senescent macrophages might be the target for prevention and treatment of RIPF.

Sign in / Sign up

Export Citation Format

Share Document