scholarly journals The Arabidopsis Histidine Phosphotransfer Proteins Are Redundant Positive Regulators of Cytokinin Signaling

2006 ◽  
Vol 18 (11) ◽  
pp. 3073-3087 ◽  
Author(s):  
Claire E. Hutchison ◽  
Jie Li ◽  
Cristiana Argueso ◽  
Monica Gonzalez ◽  
Eurie Lee ◽  
...  
Keyword(s):  
Cytokinin Signaling ◽  
Positive Regulators ◽  
Histidine Phosphotransfer

scholarly journals Two Rice Authentic Histidine Phosphotransfer Proteins, OsAHP1 and OsAHP2, Mediate Cytokinin Signaling and Stress Responses in Rice

2014 ◽  
Vol 165 (1) ◽  
pp. 335-345 ◽  
Author(s):  
Lijing Sun ◽  
Qian Zhang ◽  
Jinxia Wu ◽  
Liqing Zhang ◽  
Xuewen Jiao ◽  
...  
Keyword(s):  
Stress Responses ◽  
Cytokinin Signaling ◽  
Histidine Phosphotransfer

scholarly journals The subcellular distribution of the Arabidopsis histidine phosphotransfer proteins is independent of cytokinin signaling

2010 ◽  
Vol 62 (3) ◽  
pp. 473-482 ◽  
Author(s):  
Jayson A. Punwani ◽  
Claire E. Hutchison ◽  
G. Eric Schaller ◽  
Joseph J. Kieber
Keyword(s):  
Subcellular Distribution ◽  
Cytokinin Signaling ◽  
Histidine Phosphotransfer

scholarly journals NtbHLH1, a JAF13-like bHLH, interacts with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuxin Fan ◽  
Jiayu Peng ◽  
Jiacheng Wu ◽  
Ping Zhou ◽  
Ruijie He ◽  
...  
Keyword(s):  
Flavonoid Biosynthesis ◽  
Transcriptional Level ◽  
Flavonoid Pathway ◽  
Regulation Of Expression ◽  
Over Expression ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Regulatory Complex ◽  
Positive Regulators ◽  
R2r3 Myb

Abstract Background Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear. Results In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6. Conclusions Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.

The LARGE2-APO1/APO2 regulatory module controls panicle size and grain number in rice

2021 ◽  
Author(s):  
Luojiang Huang ◽  
Kai Hua ◽  
Ran Xu ◽  
Dali Zeng ◽  
Ruci Wang ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Loss Of Function ◽  
Grain Number ◽  
Hect Domain ◽  
Regulatory Module ◽  
Promising Target ◽  
Meristematic Activity ◽  
Positive Regulators ◽  
Genetic Mechanisms ◽  
Biochemical Analyses

Abstract Panicle size and grain number are important agronomic traits and influence grain yield in rice (Oryza sativa), but the molecular and genetic mechanisms underlying panicle size and grain number control remain largely unknown in crops. Here we report that LARGE2 encodes a HECT-domain E3 ubiquitin ligase OsUPL2 and regulates panicle size and grain number in rice. The loss of function large2 mutants produce large panicles with increased grain number, wide grains and leaves, and thick culms. LARGE2 regulates panicle size and grain number by repressing meristematic activity. LARGE2 is highly expressed in young panicles and grains. Biochemical analyses show that LARGE2 physically associates with ABERRANT PANICLE ORGANIZATION1 (APO1) and APO2, two positive regulators of panicle size and grain number, and modulates their stabilities. Genetic analyses support that LARGE2 functions with APO1 and APO2 in a common pathway to regulate panicle size and grain number. These findings reveal a novel genetic and molecular mechanism of the LARGE2-APO1/APO2 module-mediated control of panicle size and grain number in rice, suggesting that this module is a promising target for improving panicle size and grain number in crops.

scholarly journals The bacterial volatile N,N-dimethyl-hexadecylamine promotes Arabidopsis primary root elongation through cytokinin signaling and the AHK2 receptor

2021 ◽  
Vol 16 (4) ◽  
pp. 1879542
Author(s):  
Ernesto Vázquez-Chimalhua ◽  
Salvador Barrera-Ortiz ◽  
Eduardo Valencia-Cantero ◽  
José López-Bucio ◽  
León Francisco Ruiz-Herrera
Keyword(s):  
Root Elongation ◽  
Primary Root ◽  
Cytokinin Signaling

scholarly journals The Relationship between AGAMOUS and Cytokinin Signaling in the Establishment of Carpeloid Features

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 827
Author(s):  
Andrea Gómez-Felipe ◽  
Daniel Kierzkowski ◽  
Stefan de Folter
Keyword(s):  
Regulatory Network ◽  
Dependent Manner ◽  
Mads Box ◽  
Type B ◽  
Cytokinin Signaling ◽  
Reproductive Structures ◽  
Carpel Development ◽  
Gene Regulatory ◽  
The Relationship ◽  
Gynoecium Development

Gynoecium development is dependent on gene regulation and hormonal pathway interactions. The phytohormones auxin and cytokinin are involved in many developmental programs, where cytokinin is normally important for cell division and meristem activity, while auxin induces cell differentiation and organ initiation in the shoot. The MADS-box transcription factor AGAMOUS (AG) is important for the development of the reproductive structures of the flower. Here, we focus on the relationship between AG and cytokinin in Arabidopsis thaliana, and use the weak ag-12 and the strong ag-1 allele. We found that cytokinin induces carpeloid features in an AG-dependent manner and the expression of the transcription factors CRC, SHP2, and SPT that are involved in carpel development. AG is important for gynoecium development, and contributes to regulating, or else directly regulates CRC, SHP2, and SPT. All four genes respond to either reduced or induced cytokinin signaling and have the potential to be regulated by cytokinin via the type-B ARR proteins. We generated a model of a gene regulatory network, where cytokinin signaling is mainly upstream and in parallel with AG activity.

scholarly journals Secretome screening reveals immunomodulating functions of IFNα-7, PAP and GDF-7 on regulatory T-cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mei Ding ◽  
Rajneesh Malhotra ◽  
Tomas Ottosson ◽  
Magnus Lundqvist ◽  
Aman Mebrahtu ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Secreted Proteins ◽  
External Stimulation ◽  
Marker Proteins ◽  
Positive Regulators ◽  
Conformational Model

AbstractRegulatory T cells (Tregs) are the key cells regulating peripheral autoreactive T lymphocytes. Tregs exert their function by suppressing effector T cells. Tregs have been shown to play essential roles in the control of a variety of physiological and pathological immune responses. However, Tregs are unstable and can lose the expression of FOXP3 and suppressive functions as a consequence of outer stimuli. Available literature suggests that secreted proteins regulate Treg functional states, such as differentiation, proliferation and suppressive function. Identification of secreted proteins that affect Treg cell function are highly interesting for both therapeutic and diagnostic purposes in either hyperactive or immunosuppressed populations. Here, we report a phenotypic screening of a human secretome library in human Treg cells utilising a high throughput flow cytometry technology. Screening a library of 575 secreted proteins allowed us to identify proteins stabilising or destabilising the Treg phenotype as suggested by changes in expression of Treg marker proteins FOXP3 and/or CTLA4. Four proteins including GDF-7, IL-10, PAP and IFNα-7 were identified as positive regulators that increased FOXP3 and/or CTLA4 expression. PAP is a phosphatase. A catalytic-dead version of the protein did not induce an increase in FOXP3 expression. Ten interferon proteins were identified as negative regulators that reduced the expression of both CTLA4 and FOXP3, without affecting cell viability. A transcriptomics analysis supported the differential effect on Tregs of IFNα-7 versus other IFNα proteins, indicating differences in JAK/STAT signaling. A conformational model experiment confirmed a tenfold reduction in IFNAR-mediated ISG transcription for IFNα-7 compared to IFNα-10. This further strengthened the theory of a shift in downstream messaging upon external stimulation. As a summary, we have identified four positive regulators of FOXP3 and/or CTLA4 expression. Further exploration of these Treg modulators and their method of action has the potential to aid the discovery of novel therapies for both autoimmune and infectious diseases as well as for cancer.

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