AtfA bZIP-type transcription factor regulates oxidative and osmotic stress responses in Aspergillus nidulans

Abstract Storage of meristematic tissue at ultra-low temperatures offers a mean to maintain valuable genetic resources from vegetatively reproduced plants. To reveal the biology underlying cryo-stress, shoot tips of the model plant Arabidopsis thaliana were subjected to a standard preservation procedure. A transcriptomic approach was taken to describe the subsequent cellular events which occurred. The cryoprotectant treatment induced the changes in the transcript levels of genes associated with RNA processing and primary metabolism. Explants of a mutant lacking a functional copy of the transcription factor WRKY22 were compromised for recovery. A number of putative downstream targets of WRKY22 were identified, some related to phytohormone-mediated defense, to the osmotic stress response, and to development. There were also alterations in the abundance of transcript produced by genes encoding photosynthesis-related proteins. The wrky22 mutant plants developed an open stomata phenotype in response to their exposure to the cryoprotectant solution. WRKY22 probably regulates a transcriptional network during cryo-stress, linking the explant’s defense and osmotic stress responses to changes in its primary metabolism. A model is proposed linking WRKY53 and WRKY70 downstream of the action of WRKY22.

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Faculty Opinions recommendation of Aspergillus nidulans HOG pathway is activated only by two-component signalling pathway in response to osmotic stress.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1006916.322937 ◽

2005 ◽

Author(s):

Gerhard Braus

Keyword(s):

Osmotic Stress ◽

Aspergillus Nidulans ◽

Signalling Pathway ◽

Hog Pathway ◽

Two Component

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Faculty Opinions recommendation of The putative C2H2 transcription factor MtfA is a novel regulator of secondary metabolism and morphogenesis in Aspergillus nidulans.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718118231.793484774 ◽

2013 ◽

Author(s):

Margaret Katz

Keyword(s):

Transcription Factor ◽

Secondary Metabolism ◽

Aspergillus Nidulans

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Faculty Opinions recommendation of Dual DNA binding and coactivator functions of Aspergillus nidulans TamA, a Zn(II)2Cys6 transcription factor.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718358770.793496495 ◽

2014 ◽

Author(s):

Margaret Katz

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Aspergillus Nidulans

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Osmotic Stress or Ionic Composition: Which Affects the Early Growth of Crop Species More?

Agronomy ◽

10.3390/agronomy11030435 ◽

2021 ◽

Vol 11 (3) ◽

pp. 435

Author(s):

Agnieszka Ludwiczak ◽

Monika Osiak ◽

Stefany Cárdenas-Pérez ◽

Sandra Lubińska-Mielińska ◽

Agnieszka Piernik

Keyword(s):

Osmotic Stress ◽

Stress Responses ◽

Ionic Composition ◽

Degradation Process ◽

Early Growth ◽

Cultivated Plants ◽

C3 Plants ◽

Growth Stages ◽

Crop Species ◽

Ionic Salt

Salinization is a key soil degradation process. An estimated 20% of total cultivated lands and 33% of irrigated agricultural lands worldwide are affected by high salinity. Much research has investigated the influence of salt (mainly NaCl) on plants, but very little is known about how this is related to natural salinity and osmotic stress. Therefore, our study was conducted to determine the osmotic and ionic salt stress responses of selected C3 and C4 cultivated plants. We focused on the early growth stages as those critical for plant development. We applied natural brine to simulate natural salinity and to compare its effect to NaCl solution. We assessed traits related to germination ability, seedlings and plantlet morphology, growth indexes, and biomass and water accumulation. Our results demonstrate that the effects of salinity on growth are strongest among plantlets. Salinity most affected water absorption in C3 plants (28% of total traits variation), but plant length in C4 plants (17–27%). Compensatory effect of ions from brine were suggested by the higher model plants’ growth success of ca 5–7% under brine compared to the NaCl condition. However, trait differences indicated that osmotic stress was the main stress factor affecting the studied plants.

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HbxB Is a Key Regulator for Stress Response and β-Glucan Biogenesis in Aspergillus nidulans

Microorganisms ◽

10.3390/microorganisms9010144 ◽

2021 ◽

Vol 9 (1) ◽

pp. 144

Author(s):

Sung-Hun Son ◽

Mi-Kyung Lee ◽

Ye-Eun Son ◽

Hee-Soo Park

Keyword(s):

Transcription Factor ◽

Transcription Factors ◽

Aspergillus Nidulans ◽

Deletion Mutant ◽

Phenotypic Analysis ◽

Spore Viability ◽

Fungal Development ◽

Expression Of Genes ◽

Trehalose Biosynthesis

Homeobox transcription factors are conserved in eukaryotes and act as multi-functional transcription factors in filamentous fungi. Previously, it was demonstrated that HbxB governs fungal development and spore viability in Aspergillus nidulans. Here, the role of HbxB in A. nidulans was further characterized. RNA-sequencing revealed that HbxB affects the transcriptomic levels of genes associated with trehalose biosynthesis and response to thermal, oxidative, and radiation stresses in asexual spores called conidia. A phenotypic analysis found that hbxB deletion mutant conidia were more sensitive to ultraviolet stress. The loss of hbxB increased the mRNA expression of genes associated with β-glucan degradation and decreased the amount of β-glucan in conidia. In addition, hbxB deletion affected the expression of the sterigmatocystin gene cluster and the amount of sterigmatocystin. Overall, these results indicated that HbxB is a key transcription factor regulating trehalose biosynthesis, stress tolerance, β-glucan degradation, and sterigmatocystin production in A.nidulans conidia.

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