scholarly journals Genetic insights into the regulatory pathways for continuous flowering in a unique orchid Arundina graminifolia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sagheer Ahmad ◽  
Chuqiao Lu ◽  
Jie Gao ◽  
Rui Ren ◽  
Yonglu Wei ◽  
...  

Abstract Background Manipulation of flowering time and frequency of blooming is key to enhancing the ornamental value of orchids. Arundina graminifolia is a unique orchid that flowers year round, although the molecular basis of this flowering pattern remains poorly understood. Results We compared the A. graminifolia transcriptome across tissue types and floral developmental stages to elucidate important genetic regulators of flowering and hormones. Clustering analyses identified modules specific to floral transition and floral morphogenesis, providing a set of candidate regulators for the floral initiation and timing. Among candidate floral homeotic genes, the expression of two FT genes was positively correlated with flower development. Assessment of the endogenous hormone levels and qRT-PCR analysis of 32 pathway-responsive genes supported a role for the regulatory networks in floral bud control in A. graminifolia. Moreover, WGCNA showed that flowering control can be delineated by modules of coexpressed genes; especially, MEgreen presented group of genes specific to flowering. Conclusions Candidate gene selection coupled with hormonal regulators brings a robust source to understand the intricate molecular regulation of flowering in precious orchids.

2016 ◽  
Vol 107 (3) ◽  
pp. 359-368 ◽  
Author(s):  
Y. Tan ◽  
X.-R. Zhou ◽  
B.-P. Pang

AbstractQuantitative real-time PCR (qRT-PCR) has been used extensively to analyze gene expression and decipher gene function. To obtain the optimal and stable normalization factors for qRT-PCR, selection and validation of reference genes should be conducted in diverse conditions. In insects, more and more studies confirmed the necessity and importance of reference gene selection. In this study, eight traditionally used reference genes in Galeruca daurica (Joannis) were assessed, using qRT-PCR, for suitability as normalization genes under different experimental conditions using four statistical programs: geNorm, Normfinder, BestKeeper and the comparative ΔCt method. The genes were ranked from the most stable to the least stable using RefFinder. The optimal suite of recommended reference genes was as follows: succinate dehydrogenase (SDHA) and tubulin-alpha (TUB-α) for temperature-treated larvae; ribosomal protein L32, SDHA and glutathione S-transferase were best for all developmental stages; ACT and TUB-α for male and female adults; SDHA and TUB-α were relatively stable and expressed in different tissues, both diapause and non-diapause adults. Reference gene evaluation was validated using expression of two target genes: the P450 CYP6 gene and the heat shock protein gene Hsp70. These results confirm the importance of custom reference gene selection when studies are conducted under diverse experimental conditions. A standardized qRT-PCR analysis procedure for gene functional studies is provided that could be useful in studies on other insect species.


2020 ◽  
Author(s):  
Qian Zhang ◽  
Xue Gao ◽  
Lian-Juan Wang ◽  
Yu-Qian Zhao ◽  
Gui-Xia Jia

Abstract Background: The selection of reliable reference genes is a critical element for obtaining accurate gene expression data to assess quantitative real-time polymerase chain reaction (qRT-PCR) performance. It is critical to use suitable reference genes in miRNA qRT-PCR because of short amplification products and large differences in the expression levels of target miRNAs involved in some biological processes. However, in lily, which exhibits a large complex genome but lacks a reference, the available miRNA reference genes for use in qRT-PCR under various treatment conditions are limited, and their reliability has rarely been systematically evaluated.Results: In this study, 8 candidate reference genes, including three classic housekeeping genes and five potential miRNAs from the miRNA library of L. × formolongi, were selected and assessed for expression stability utilizing the BestKeeper, geNorm and Normfinder tools, together with the Delta Ct method, across a diverse set of biotic and abiotic experimental conditions (developmental stages, tissues, heat stress and pathogen defence) to determine the best reference gene(s) for L. × formolongi and L. regale. The final ranking was reordered by using RankAggreg, and the results showed that the novel miRNA PC-3p-67_108977 and the conserved miRNAs miR399a, miR399a and U6 were the most stable genes for L. × formolongi and L. regale, respectively, under all tested experimental conditions. Additionally, PC-3p-67_108977 and U6 were the most suitable genes for qRT-PCR studies in lily.Conclusions: This study provides a comprehensive evaluation of the reliability of reference genes for miRNA studies on development and biotic and abiotic stress responses in different lilies. These results will be beneficial for miRNA identification and functional studies of lilies in the future.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 909
Author(s):  
Anyela Valentina Camargo Rodriguez

Senescence is the final stage of leaf development and is critical for plants’ fitness as nutrient relocation from leaves to reproductive organs takes place. Although senescence is key in nutrient relocation and yield determination in cereal grain production, there is limited understanding of the genetic and molecular mechanisms that control it in major staple crops such as wheat. Senescence is a highly orchestrated continuum of interacting pathways throughout the lifecycle of a plant. Levels of gene expression, morphogenesis, and phenotypic development all play key roles. Yet, most studies focus on a short window immediately after anthesis. This approach clearly leaves out key components controlling the activation, development, and modulation of the senescence pathway before anthesis, as well as during the later developmental stages, during which grain development continues. Here, a computational multiscale modelling approach integrates multi-omics developmental data to attempt to simulate senescence at the molecular and plant level. To recreate the senescence process in wheat, core principles were borrowed from Arabidopsis Thaliana, a more widely researched plant model. The resulted model describes temporal gene regulatory networks and their effect on plant morphology leading to senescence. Digital phenotypes generated from images using a phenomics platform were used to capture the dynamics of plant development. This work provides the basis for the application of computational modelling to advance understanding of the complex biological trait senescence. This supports the development of a predictive framework enabling its prediction in changing or extreme environmental conditions, with a view to targeted selection for optimal lifecycle duration for improving resilience to climate change.


Author(s):  
Nawrah Khader ◽  
Virlana M Shchuka ◽  
Oksana Shynlova ◽  
Jennifer A Mitchell

Abstract The onset of labour is a culmination of a series of highly coordinated and preparatory physiological events that take place throughout the gestational period. In order to produce the associated contractions needed for fetal delivery, smooth muscle cells in the muscular layer of the uterus (i.e. myometrium) undergo a transition from quiescent to contractile phenotypes. Here, we present the current understanding of the roles transcription factors play in critical labour-associated gene expression changes as part of the molecular mechanistic basis for this transition. Consideration is given to both transcription factors that have been well-studied in a myometrial context, i.e. activator protein 1 (AP-1), progesterone receptors (PRs), estrogen receptors (ERs), and nuclear factor kappa B (NF-κB), as well as additional transcription factors whose gestational event-driving contributions have been demonstrated more recently. These transcription factors may form pregnancy- and labour- associated transcriptional regulatory networks in the myometrium to modulate the timing of labour onset. A more thorough understanding of the transcription factor-mediated, labour-promoting regulatory pathways holds promise for the development of new therapeutic treatments that can be used for the prevention of preterm labour in at-risk women.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shiyi Zheng ◽  
Yukang Huang ◽  
Hongyun Huang ◽  
Bin Yu ◽  
Ni Zhou ◽  
...  

Abstract Background Nosema bombycis is a unicellular eukaryotic pathogen of the silkworm, Bombyx mori, and is an economic and occupational hazard in the silkworm industry. Because of its long incubation period and horizontal and vertical transmission, it is subject to quarantine measures in sericulture production. The microsporidian life-cycle includes a dormant extracellular phase and intracellular proliferation phase, with the proliferation period being the most active period. This latter period lacks spore wall protection and may be the most susceptible stage for control. Methods In order to find suitable target for the selective breeding of N. bombycis-resistant silkworm strains, we screen highly expressed membrane proteins from the transcriptome data of N. bombycis. The subcellular localization of the candidate protein was verified by Indirect immunofluorescence analysis (IFA) and immunoelectron microscopy (IEM), and its role in N. bombycis proliferation was verified by RNAi. Results The N. bombycis protein (NBO_76g0014) was identified as a transmembrane protein and named NbTMP1. It is homologous with hypothetical proteins NGRA_1734 from Nosema granulosis. NbTMP1 has a transmembrane region of 23 amino acids at the N-terminus. Indirect immunofluorescence analysis (IFA) results suggest that NbTMP1 is secreted on the plasma membrane as the spores develop. Western blot and qRT-PCR analysis showed that NbTMP1 was expressed in all developmental stages of N. bombycis in infected cells and in the silkworm midgut. Downregulation of NbTMP1 expression resulted in significant inhibition of N. bombycis proliferation. Conclusions We confirmed that NbTMP1 is a membrane protein of N. bombycis. Reduction of the transcription level of NbTMP1 significantly inhibited N. bombycis proliferation, and this protein may be a target for the selective breeding of N. bombycis-resistant silkworm strains.


2021 ◽  
Vol 22 (13) ◽  
pp. 7029
Author(s):  
Cai-Yun Xiong ◽  
Qing-You Gong ◽  
Hu Pei ◽  
Chang-Jian Liao ◽  
Rui-Chun Yang ◽  
...  

In maize, the ear shank is a short branch that connects the ear to the stalk. The length of the ear shank mainly affects the transportation of photosynthetic products to the ear, and also influences the dehydration of the grain by adjusting the tightness of the husks. However, the molecular mechanisms of maize shank elongation have rarely been described. It has been reported that the maize ear shank length is a quantitative trait, but its genetic basis is still unclear. In this study, RNA-seq was performed to explore the transcriptional dynamics and determine the key genes involved in maize shank elongation at four different developmental stages. A total of 8145 differentially expressed genes (DEGs) were identified, including 729 transcription factors (TFs). Some important genes which participate in shank elongation were detected via function annotation and temporal expression pattern analyses, including genes related to signal transduction hormones (auxin, brassinosteroids, gibberellin, etc.), xyloglucan and xyloglucan xyloglucosyl transferase, and transcription factor families. The results provide insights into the genetic architecture of maize ear shanks and developing new varieties with ideal ear shank lengths, enabling adjustments for mechanized harvesting in the future.


2021 ◽  
Author(s):  
Wenpeng Zhu ◽  
Manyu Zhang ◽  
Jianyi Li ◽  
Hewen Zhao ◽  
Kezhong Zhang ◽  
...  

Abstract BackgroundAcer rubrum L. is a colorful ornamental tree with great economic value. Because this tree is difficult to root under natural conditions and the seedling survival rate is low, vegetative propagation methods are often used. Because the formation of adventitious roots (ARs) is essential for the survival of asexual propagation of A. rubrum, it is necessary to investigate the molecular regulatory mechanisms in the formation of ARs of A. ruburm. To address this knowledge gap, we sequenced the transcriptome and sRNA of the A. rubrum variety ‘Autumn Fantasy’ using high-throughput sequencing and explored changes in gene and microRNA (miRNA) expression in response to exogenous auxin treatment. ResultsWe identified 82,468 differentially expressed genes between the treated and untreated ARs, as well as 48 known and 95 novel miRNAs. We also identified 172 target genes of the known miRNAs using degradome sequencing. Two regulatory pathways (ubiquitin mediated proteolysis and plant hormone signal transduction), Ar-miR160a and the target gene ArARF10 were shown to be involved in the auxin response. We further investigated the expression patterns and regulatory roles of ArARF10 through subcellular localization, transcriptional activation, plant transformation, qRT-PCR analysis, and GUS staining. ConclusionsDifferential expression patterns indicated the Ar-miR160a-ArARF10 interaction might play a significant role in the regulation of AR formation in A. rubrum. Our study provided new insights into mechanisms underlying the regulation of AR formation in A. rubrum.


Author(s):  
S. M. Nifantova ◽  
I. K. Komarnytskyi ◽  
M. V. Kuchuk

Aim. The production of alfalfa and peanut cultivars with new properties is necessary. The purpose of this work was to develop Agrobacterium-mediated transformation protocol and to construct transgenic alfalfa and peanut plants resistant to herbicide Pursuit Methods. Genetic transformation was carried out using cocultivation of peanut and alfalfa explants with Agrobacterium tumefaciens strain GV3101 carrying genetic construct pCB004 containing mutant ahas/als gene and nptII gene. Selection was held on the solidified callus inducing medium with 50 mkg/l Pursuit. The selected callus clones were put on the regeneration medium with the same selective agents. Obtained regeneration lines were analysed using PCR-analysis. Results. 17 peanut and 14 alfalfa regeneration lines had positive signals after PCR analysis with DNA fragments of required molecular size for ahas/als and nptII genes. Conclusions. Transgenic alfalfa and peanut plants resistant to the herbicide Pursuit were obtained.Keywords: alfalfa, peanut, ahas/als gene, transformation.


2021 ◽  
Vol 13 (Aquaculture) ◽  
pp. 79-85
Author(s):  
Thi Hoang Oanh Dang ◽  
Thi Nhu Thuy Nguyen ◽  
Ngoc Ut Vu

A total of 291 white leg shrimp samples were collected from 70 cultured ponds in Soc Trang, Bac Lieu and Ca Mau provinces in the Mekong Delta and subjected to endoparasitic detection in the digestive tract. Collected shrimps displayed unhealthy behaviors such as stop or less feeding and lethagic swimming. Pathological signs in the gastrointestinal tract include (1) empty midgut and stomach together with pale and atrophy hepatopancreas; (2) empty, little or discontinued food in the midgut; (3) slow growth and variation in sizes; and (4) white feces. The results from fresh and Giemsa stained smears methods revealed that 96.5% of sampled shrimps were infected by gregarine parasite at different developmental stages. A prevalence infection of 24.7% was recorded with Vermiform present in the hepatopancreas by fresh smear and histology. Histopathological analysis noted that 7.9% of collected shrimp samples had Enterocytozoon hepatopenaei (EHP) spores in hepatopancreas and midgut and confirmed by PCR analysis.


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