Heterologous myb genes distinct from GL1 enhance trichome production when overexpressed in Nicotiana tabacum

Development ◽  
1999 ◽  
Vol 126 (4) ◽  
pp. 671-682 ◽  
Author(s):  
T. Payne ◽  
J. Clement ◽  
D. Arnold ◽  
A. Lloyd

Myb-class transcription factors implicated in cell shape regulation were overexpressed in Arabidopsis thaliana and Nicotiana tabacum in an attempt to assess the extent to which cellular differentiation programs might be shared between these distantly related plants. GLABROUS 1, a myb gene required for trichome development in Arabidopsis, did not alter the trichome phenotype of the tobacco plants in which it was overexpressed. MIXTA, which in Antirrhinum majus is reported to regulate certain aspects of floral papillae development, did not complement the glabrous 1 mutant of Arabidopsis. However, 35S:MIXTA transformants of N. tabacum displayed various developmental abnormalities, most strikingly production of supernumerary trichomes on cotyledons, leaves and stems. In addition, floral papillae were converted to multicellular trichomes. CotMYBA, a myb gene which is expressed in Gossypium hirsutum ovules and has some homology to MIXTA, was also overexpressed in the two species. A similar but distinct syndrome of abnormalities, including the production of cotyledonary trichomes, was observed in 35S:CotMYBA tobacco transformants. However, CotMYBA did not alter trichome production in Arabidopsis. These results suggest that the trichomes of Arabidopsis and Nicotiana are merely analogous structures, and that the myb genes regulating their differentiation are specific and separate.

2021 ◽  
Author(s):  
Yuan Yuan ◽  
Xiping Yang ◽  
Mengfang Feng ◽  
Hongyan Ding ◽  
Khan Muhammad Tahir ◽  
...  

Abstract Background: Sugarcane (Saccharum) is the most important sugar crop in the world. As one of the most enriched transcription factor families in plants, MYB genes display a great potential to contribute to sugarcane improvement by trait modification. We have identified the sugarcane MYB gene family at a whole-genome level through systematic evolution analyses and expression profiling. R2R3-MYB is a large subfamily involved in many plant-specific processes. Results: A total of 202 R2R3-MYB genes (356 alleles) were identified in the polyploid Saccharum spontaneum genome and classified into 15 subgroups by phylogenetic analysis. The sugarcane MYB family had more members by a comparative analysis in sorghum and significant advantages among most plants, especially grasses. Collinearity analysis revealed that 70% of the SsR2R3-MYB genes had experienced duplication events, logically suggesting the contributors to the MYB gene family expansion. Functional characterization was performed to identify 56 SsR2R3-MYB genes involved in various plant bioprocesses with expression profiling analysis on 60 RNA-seq databases. We identified 22 MYB genes specifically expressed in the stem, of which MYB43, MYB53, MYB65, MYB78, and MYB99 were validated by qPCR. Allelic expression dominance in the stem was more significant than that in the leaf, implying the differential expression of alleles may be responsible for the high expression of MYB in the stem. MYB169, MYB181, MYB192 were identified as candidate C4 photosynthetic regulators by C4 expression pattern and robust circadian oscillations. Furthermore, stress expression analysis showed that MYB36, MYB48, MYB54, MYB61 actively responded to drought treatment; 19 and 10 MYB genes were involved in response to the sugarcane pokkah boeng and mosaic disease, respectively. Conclusions: A Genome-wide expression analysis demonstrated that SsMYB genes were involved in stem development and stress response. This study largely contributed to understanding the extent to which MYB transcription factors investigate regulatory mechanisms and functional divergence in sugarcane.


1995 ◽  
Vol 73 (7) ◽  
pp. 959-981 ◽  
Author(s):  
George W. Haughn ◽  
Elizabeth A. Schultz ◽  
Jose M. Martinez-Zapater

In the last decade, the study of mutants defective in floral development has contributed significantly to our understanding of floral evocation and morphogenesis. Genes in Arabidopsis thaliana and Antirrhinum majus that play key roles in (i) the transition from the vegetative to reproductive phase, (ii) the activation of floral development in specific shoots, and (iii) the unique arrangement of floral organs have been identified genetically and in many cases cloned. Many of the genes appear to encode transcription factors that act to select specific developmental programs of division and differentiation for groups of primordial cells. Other genes may be involved in detecting environmental conditions and transducing the signal to the developing meristems. Key questions remaining include how the regulatory proteins are produced in specific temporal and spatial patterns, interact with each other and initiate specific morphological programs. Although current research on floral morphogenesis has been limited to only a few species there is growing evidence that the basic processes are common to all flowering plants.Thus the information and tools currently being generated should be useful for studying a wide variety of flowering species. It seems reasonable to predict that within the next decade, we should have a fairly complete understanding of the basic mechanisms underlying floral morphogenesis and its evolution among the angiosperms. Key words: Arabidopsis thaliana, floral morphogenesis, molecular genetics.


Insects ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 16
Author(s):  
Dan-Mei Yao ◽  
Chi Zou ◽  
Yan-Ni Shu ◽  
Shu-Sheng Liu

WRKY transcription factors are key regulators of many plant processes, most notably coping with biotic and abiotic stresses. Recently, the function of WRKY in plant defense against phloem-feeding insects such as whitefly (Bemisia tabaci) has been brought to attention. In this study, we found that the expression levels of Nicotiana tabacum WRKY4, WRKY6 and WRKY10 were significantly upregulated when tobacco plants were infested with whiteflies or treated with salicylic acid. Compared to controls, whiteflies lived longer and laid more eggs on NtWRKY-silenced tobacco plants but performed less well on NtWRKY-overexpressing plants. The three NtWRKYs interacted with five mitogen-activated protein kinases (NtMAPKs) in vivo and in vitro. These results suggest that the WRKYs in tobacco positively modulate plant defense against whiteflies through interaction with the mitogen-activated protein kinase cascade (MAPK cascade) pathways, and thus provide new insights into plant defense against phloem-feeding insects.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yuan Yuan ◽  
Xiping Yang ◽  
Mengfan Feng ◽  
Hongyan Ding ◽  
Muhammad Tahir Khan ◽  
...  

Abstract Background Sugarcane (Saccharum) is the most critical sugar crop worldwide. As one of the most enriched transcription factor families in plants, MYB genes display a great potential to contribute to sugarcane improvement by trait modification. We have identified the sugarcane MYB gene family at a whole-genome level through systematic evolution analyses and expression profiling. R2R3-MYB is a large subfamily involved in many plant-specific processes. Results A total of 202 R2R3-MYB genes (356 alleles) were identified in the polyploid Saccharum spontaneum genomic sequence and classified into 15 subgroups by phylogenetic analysis. The sugarcane MYB family had more members by a comparative analysis in sorghum and significant advantages among most plants, especially grasses. Collinearity analysis revealed that 70% of the SsR2R3-MYB genes had experienced duplication events, logically suggesting the contributors to the MYB gene family expansion. Functional characterization was performed to identify 56 SsR2R3-MYB genes involved in various plant bioprocesses with expression profiling analysis on 60 RNA-seq databases. We identified 22 MYB genes specifically expressed in the stem, of which RT-qPCR validated MYB43, MYB53, MYB65, MYB78, and MYB99. Allelic expression dominance analysis implied the differential expression of alleles might be responsible for the high expression of MYB in the stem. MYB169, MYB181, MYB192 were identified as candidate C4 photosynthetic regulators by C4 expression pattern and robust circadian oscillations. Furthermore, stress expression analysis showed that MYB36, MYB48, MYB54, MYB61 actively responded to drought treatment; 19 and 10 MYB genes were involved in response to the sugarcane pokkah boeng and mosaic disease, respectively. Conclusions This is the first report on genome-wide analysis of the MYB gene family in sugarcane. SsMYBs probably played an essential role in stem development and the adaptation of various stress conditions. The results will provide detailed insights and rich resources to understand the functional diversity of MYB transcription factors and facilitate the breeding of essential traits in sugarcane.


2019 ◽  
Author(s):  
Alexandra Plotnikova ◽  
Max J. Kellner ◽  
Magdalena Mosiolek ◽  
Michael A. Schon ◽  
Michael D. Nodine

SummaryMicroRNAs (miRNAs) are short non-coding RNAs that mediate the repression of target transcripts in plants and animals. Although miRNAs are required throughout plant development, relatively little is known regarding their embryonic functions. To systematically characterize embryonic miRNAs in Arabidopsis thaliana, we developed or applied high-throughput sequencing based methods to profile hundreds of miRNAs and associated targets throughout embryogenesis. We discovered dozens of miRNAs that dynamically cleave and repress target transcripts including 30 that encode transcription factors. Transcriptome analyses indicated that these miRNA:target interactions have a profound impact on embryonic gene expression programs, and we further demonstrated that the miRNA-mediated repression of six transcription factors were individually required for embryo morphogenesis. These data indicate that the miRNA-directed repression of multiple transcription factors is critically important for the establishment of the plant body plan, and provide a foundation to further investigate how miRNAs contribute to these initial cellular differentiation events.


2021 ◽  
Vol 22 (12) ◽  
pp. 6401
Author(s):  
Younglan Lim ◽  
Nam-On Ku

Although hepatocellular carcinoma (HCC) is developed with various etiologies, protection of hepatocytes seems basically essential to prevent the incidence of HCC. Keratin 8 and keratin 18 (K8/K18) are cytoskeletal intermediate filament proteins that are expressed in hepatocytes. They maintain the cell shape and protect cells under stress conditions. Their protective roles in liver damage have been described in studies of mouse models, and K8/K18 mutation frequency in liver patients. Interestingly, K8/K18 bind to signaling proteins such as transcription factors and protein kinases involved in HCC development. Since K8/K18 are abundant cytoskeletal proteins, K8/K18 binding with the signaling factors can alter the availability of the factors. Herein, we discuss the potential roles of K8/K18 in HCC development.


1970 ◽  
Vol 44 (3-4) ◽  
pp. 323-328 ◽  
Author(s):  
R. S. Tandon ◽  
S. P. Singh

Two new species belonging to two different families of the super-family Aphelenchoidea are described. The material was obtained from the roots of tobacco plants, Nicotiana tabacum.The worms were killed by hot water, fixed in F.A.A. solution, cleared in 1% glycerine alcohol mixture and mounted in pure glycerine.


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