scholarly journals Distinct Cell-Specific Expression of Homospermidine Synthase Involved in Pyrrolizidine Alkaloid Biosynthesis in Three Species of the Boraginales

2012 ◽  
Vol 159 (3) ◽  
pp. 920-929 ◽  
Author(s):  
Daniel Niemüller ◽  
Andreas Reimann ◽  
Dietrich Ober
Keyword(s):  
Pyrrolizidine Alkaloid ◽  
Alkaloid Biosynthesis ◽  
Specific Expression ◽  
Distinct Cell ◽  
Homospermidine Synthase

scholarly journals Pyrrolizidine Alkaloid Biosynthesis in Phalaenopsis Orchids: Developmental Expression of Alkaloid-Specific Homospermidine Synthase in Root Tips and Young Flower Buds

2008 ◽  
Vol 148 (2) ◽  
pp. 751-760 ◽  
Author(s):  
Sven Anke ◽  
Daniela Gondé ◽  
Elisabeth Kaltenegger ◽  
Robert Hänsch ◽  
Claudine Theuring ◽  
...  
Keyword(s):  
Pyrrolizidine Alkaloid ◽  
Developmental Expression ◽  
Alkaloid Biosynthesis ◽  
Root Tips ◽  
Flower Buds ◽  
Homospermidine Synthase

scholarly journals The Orphan Crop Crassocephalum crepidioides Accumulates the Pyrrolizidine Alkaloid Jacobine in Response to Nitrogen Starvation

2021 ◽  
Vol 12 ◽  
Author(s):  
Sebastian Schramm ◽  
Wilfried Rozhon ◽  
Adebimpe N. Adedeji-Badmus ◽  
Yuanyuan Liang ◽  
Shahran Nayem ◽  
...  
Keyword(s):  
Pyrrolizidine Alkaloid ◽  
Sub Saharan Africa ◽  
Close Relative ◽  
Environmental Cues ◽  
N Deficiency ◽  
Sub Saharan ◽  
Rate Limiting ◽  
Homospermidine Synthase ◽  
Orphan Crop

Crassocephalum crepidioides is an African orphan crop that is used as a leafy vegetable and medicinal plant. Although it is of high regional importance in Sub-Saharan Africa, the plant is still mainly collected from the wild and therefore efforts are made to promote its domestication. However, in addition to beneficial properties, there was first evidence that C. crepidioides can accumulate the highly toxic pyrrolizidine alkaloid (PA) jacobine and here it was investigated, how jacobine production is controlled. Using ecotypes from Africa and Asia that were characterized in terms of their PA profiles, it is shown that the tetraploid C. crepidioides forms jacobine, an ability that its diploid close relative Crassocephalum rubens appears to lack. Evidence is provided that nitrogen (N) deficiency strongly increases jacobine in the leaves of C. crepidioides, that this capacity depends more strongly on the shoot than the root system, and that homospermidine synthase (HSS) activity is not rate-limiting for this reaction. A characterization of HSS gene representation and transcription showed that C. crepidioides and C. rubens possess two functional versions, one of which is conserved, that the HSS transcript is mainly present in roots and that its abundance is not controlled by N deficiency. In summary, this work improves our understanding of how environmental cues impact PA biosynthesis in plants and provides a basis for the development of PA-free C. crepidioides cultivars, which will aid its domestication and safe use.

scholarly journals Identification of a Second Site of Pyrrolizidine Alkaloid Biosynthesis in Comfrey to Boost Plant Defense in Floral Stage,

2017 ◽  
Vol 174 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Lars H. Kruse ◽  
Thomas Stegemann ◽  
Christian Sievert ◽  
Dietrich Ober
Keyword(s):  
Plant Defense ◽  
Pyrrolizidine Alkaloid ◽  
Alkaloid Biosynthesis

scholarly journals Upregulation and cell specificity of C4 genes are derived from ancestral C3 gene regulatory networks

2020 ◽  
Author(s):  
Pallavi Singh ◽  
Sean R. Stevenson ◽  
Ivan Reyna-Llorens ◽  
Gregory Reeves ◽  
Tina B. Schreier ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Cell Types ◽  
Chromatin Accessibility ◽  
Transcript Accumulation ◽  
Specific Expression ◽  
Cell Specificity ◽  
Distinct Cell ◽  
Gene Regulatory

ABSTRACTThe efficient C4 pathway is based on strong up-regulation of genes found in C3 plants, but also compartmentation of their expression into distinct cell-types such as the mesophyll and bundle sheath. Transcription factors associated with these phenomena have not been identified. To address this, we undertook genome-wide analysis of transcript accumulation, chromatin accessibility and transcription factor binding in C4Gynandropsis gynandra. From these data, two models relating to the molecular evolution of C4 photosynthesis are proposed. First, increased expression of C4 genes is associated with increased binding by MYB-related transcription factors. Second, mesophyll specific expression is associated with binding of homeodomain transcription factors. Overall, we conclude that during evolution of the complex C4 trait, C4 cycle genes gain cis-elements that operate in the C3 leaf such that they become integrated into existing gene regulatory networks associated with cell specificity and photosynthesis.

scholarly journals An Opaque Cell-Specific Expression Program of Secreted Proteases and Transporters Allows Cell-Type Cooperation in Candida albicans

Genetics ◽  
2020 ◽  
Vol 216 (2) ◽  
pp. 409-429
Author(s):  
Matthew B. Lohse ◽  
Lucas R. Brenes ◽  
Naomi Ziv ◽  
Michael B. Winter ◽  
Charles S. Craik ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Opportunistic Pathogen ◽  
Cell Types ◽  
Specific Expression ◽  
Environmental Signals ◽  
Single Genome ◽  
Distinct Cell ◽  
Secreted Proteases ◽  
Expression Program

An unusual feature of the opportunistic pathogen Candida albicans is its ability to switch stochastically between two distinct, heritable cell types called white and opaque. Here, we show that only opaque cells, in response to environmental signals, massively upregulate a specific group of secreted proteases and peptide transporters, allowing exceptionally efficient use of proteins as sources of nitrogen. We identify the specific proteases [members of the secreted aspartyl protease (SAP) family] needed for opaque cells to proliferate under these conditions, and we identify four transcriptional regulators of this specialized proteolysis and uptake program. We also show that, in mixed cultures, opaque cells enable white cells to also proliferate efficiently when proteins are the sole nitrogen source. Based on these observations, we suggest that one role of white-opaque switching is to create mixed populations where the different phenotypes derived from a single genome are shared between two distinct cell types.

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