scholarly journals Genetic Analysis of Gibberellin Signal Transduction

1996 ◽  
Vol 112 (1) ◽  
pp. 11-17 ◽  
Author(s):  
S. M. Swain ◽  
N. E. Olszewski
Keyword(s):  
Signal Transduction ◽  
Genetic Analysis

scholarly journals Molecular genetic analysis of cold–regulated gene transcription

2002 ◽  
Vol 357 (1423) ◽  
pp. 877-886 ◽  
Author(s):  
C. Viswanathan ◽  
Jian-Kang Zhu
Keyword(s):  
Signal Transduction ◽  
Genetic Analysis ◽  
Cold Stress ◽  
Gene Transcription ◽  
Cold Hardiness ◽  
Negative Regulator ◽  
Clear Understanding ◽  
Stress Signal ◽  
Responsive Gene ◽  
Responsive Element

Chilling and freezing temperatures adversely affect the productivity and quality of crops. Hence improving the cold hardiness of crop plants is an important goal in agriculture, which demands a clear understanding of cold stress signal perception and transduction. Pharmacological and biochemical evidence shows that membrane rigidification followed by cytoskeleton rearrangement, Ca 2+ influx and Ca 2+ –dependent phosphorylation are involved in cold stress signal transduction. Cold–responsive genes are regulated through C–repeat/dehydration–responsive elements (CRT/DRE) and abscisic acid (ABA)–responsive element cis elements by transacting factors C–repeat binding factors/dehydration–responsive element binding proteins (CBFs/DREBs) and basic leucine zippers (bZIPs) (SGBF1), respectively. We have carried out a forward genetic analysis using chemically mutagenized Arabidopsis plants expressing cold–responsive RD29A promoter–driven luciferase to dissect cold signal transduction. We have isolated the fiery1 ( fry1 ) mutant and cloned the FRY1 gene, which encodes an inositol polyphosphate 1–phosphatase. The fry1 plants showed enhanced induction of stress genes in response to cold, ABA, salt and dehydration due to higher accumulation of the second messenger, inositol (1,4,5)– triphosphate (IP 3 ). Thus our study provides genetic evidence suggesting that cold signal is transduced through changes in IP 3 levels. We have also identified the hos1 mutation, which showed super induction of cold–responsive genes and their transcriptional activators. Molecular cloning and characterization revealed that HOS1 encodes a ring finger protein, which has been implicated as an E3 ubiquitin conjugating enzyme. HOS1 is present in the cytoplasm at normal growth temperatures but accumulates in the nucleus upon cold stress. HOS1 appears to regulate temperature sensing by the cell as cold–responsive gene expression occurs in the hos1 mutant at relatively warm temperatures. Thus HOS1 is a negative regulator, which may be functionally linked to cellular thermosensors to modulate cold–responsive gene transcription.

scholarly journals Complementation of the Magnaporthe grisea ΔcpkA Mutation by the Blumeria graminis PKA-c Gene: Functional Genetic Analysis of an Obligate Plant Pathogen

2001 ◽  
Vol 14 (12) ◽  
pp. 1368-1375 ◽  
Author(s):  
Lene Bindslev ◽  
Michael J. Kershaw ◽  
Nicholas J. Talbot ◽  
Richard P. Oliver
Keyword(s):  
Signal Transduction ◽  
Genetic Analysis ◽  
Magnaporthe Grisea ◽  
Functional Characterization ◽  
Pathogenic Fungi ◽  
Blumeria Graminis ◽  
Powdery Mildew Fungus ◽  
Reading Frame ◽  
Related Development ◽  
Obligate Pathogen

Obligate plant-pathogenic fungi have proved extremely difficult to characterize with molecular genetics because they cannot be cultured away from host plants and only can be manipulated experimentally in limited circumstances. Previously, in order to characterize signal transduction processes during infection-related development of the powdery mildew fungus Blumeria graminis (syn. Erysiphe graminis) f. sp. hordei, we described a gene similar to the catalytic subunit of cyclic AMP-dependent protein kinase A (here renamed Bka1). Functional characterization of this gene has been achieved by expression in a ΔcpkA mutant of the nonobligate pathogen Magnaporthe grisea. This nonpathogenic M. grisea ΔcpkA mutant displays delayed and incomplete appressorium development, suggesting a role for PKA-c in the signal transduction processes that control the maturation of infection cells. Transformation of the ΔcpkA mutant with the mildew Bka1 open reading frame, controlled by the M. grisea MPG1 promoter, restored pathogenicity and appressorium maturation kinetics. The results provide, to our knowledge, the first functional genetic analysis of pathogenicity in an obligate pathogen and highlight the remarkable conservation of signaling components regulating infection-related development in pathogenic fungi.

scholarly journals Chemical Genetic Analysis of the Time Course of Signal Transduction by JNK

2006 ◽  
Vol 21 (5) ◽  
pp. 701-710 ◽  
Author(s):  
Juan-Jose Ventura ◽  
Anette Hübner ◽  
Chao Zhang ◽  
Richard A. Flavell ◽  
Kevan M. Shokat ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Genetic Analysis ◽  
Time Course ◽  
Chemical Genetic
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