Sucrose and light regulation of a cold-inducible UDP-glucose pyrophosphorylase gene via a hexokinase-independent and abscisic acid-insensitive pathway in Arabidopsis

UDP-glucose pyrophosphorylase (UGPase) is a key enzyme producing UDP-glucose, which is involved in an array of metabolic pathways concerned with, among other functions, the synthesis of sucrose and cellulose. An Arabidopsis thaliana UGPase-encoding gene, Ugp, was profoundly up-regulated by feeding sucrose to the excised leaves and by an exposure of plants to low temperature (5°C). The UGPase activity and its protein content also increased under conditions of sucrose feeding and exposure to cold. The sucrose effect on Ugp was apparently specific and was mimicked by exposure of dark-adapted leaves to light. Drought and O2 deficiency had some down-regulating effects on expression of Ugp. The sugar-signalling pathway for Ugp regulation was independent of hexokinase, as was found by using transgenic plants with increased and decreased expression of the corresponding gene. Subjecting mutants deficient in abscisic acid (ABA) to cold stress conditions had no effect on Ugp expression profiles. Okadaic acid was a powerful inhibitor of Ugp expression, whereas it up-regulated the gene encoding sucrose synthase (Sus1), indicating distinct transduction pathways in transmitting the sugar signal for the two genes in A. thaliana. We suggest that Ugp gene expression is mediated via a hexokinase-independent and ABA-insensitive pathway that involves an okadaic acid-responsive protein phosphatase. The data point towards Ugp as a possible regulatory entity that is closely involved in the homoeostatic readjustment of plant responses to environmental signals.

Download Full-text

Erratum to: “Cloning of 9-cis-epoxycarotenoid dioxygenase (NCED) gene encoding a key enzyme during abscisic acid (ABA) biosynthesis and ABA-regulated ethylene production in detached young persimmon calyx”

Chinese Science Bulletin ◽

10.1007/s11434-009-0685-2 ◽

2009 ◽

Vol 54 (21) ◽

pp. 3990-3990 ◽

Cited By ~ 7

Author(s):

Ping Leng ◽

GuangLian Zhang ◽

XiangXin Li ◽

LiangHe Wang ◽

ZhongMing Zheng

Keyword(s):

Abscisic Acid ◽

Ethylene Production ◽

Gene Encoding ◽

Key Enzyme ◽

Nced Gene ◽

Aba Biosynthesis

Download Full-text

Regulation of Alginate Biosynthesis inPseudomonas syringae pv. syringae

Journal of Bacteriology ◽

10.1128/jb.181.11.3478-3485.1999 ◽

1999 ◽

Vol 181 (11) ◽

pp. 3478-3485 ◽

Cited By ~ 21

Author(s):

Mohamed K. Fakhr ◽

Alejandro Peñaloza-Vázquez ◽

Ananda M. Chakrabarty ◽

Carol L. Bender

Keyword(s):

Sigma Factor ◽

Promoter Region ◽

Biosynthetic Pathway ◽

Response Regulator ◽

Consensus Sequence ◽

Gene Encoding ◽

Environmental Signals ◽

Alginate Production ◽

Key Enzyme ◽

Alginate Biosynthesis

ABSTRACT Both Pseudomonas aeruginosa and the phytopathogenP. syringae produce the exopolysaccharide alginate. However, the environmental signals that trigger alginate gene expression in P. syringae are different from those inP. aeruginosa with copper being a major signal in P. syringae. In P. aeruginosa, the alternate sigma factor encoded by algT (ς22) and the response regulator AlgR1 are required for transcription of algD, a gene which encodes a key enzyme in the alginate biosynthetic pathway. In the present study, we cloned and characterized the gene encoding AlgR1 from P. syringae. The deduced amino acid sequence of AlgR1 from P. syringae showed 86% identity to its P. aeruginosa counterpart. Sequence analysis of the region flankingalgR1 in P. syringae revealed the presence ofargH, algZ, and hemC in an arrangement virtually identical to that reported in P. aeruginosa. An algR1 mutant, P. syringaeFF5.32, was defective in alginate production but could be complemented when algR1 was expressed in trans. ThealgD promoter region in P. syringae(PsalgD) was also characterized and shown to diverge significantly from the algD promoter in P. aeruginosa. Unlike P. aeruginosa, algR1was not required for the transcription of algD in P. syringae, and PsalgD lacked the consensus sequence recognized by AlgR1. However, both the algD andalgR1 upstream regions in P. syringae contained the consensus sequence recognized by ς22, suggesting thatalgT is required for transcription of both genes.

Download Full-text

Cloning of 9-cis-epoxycarotenoid dioxygenase (NCED) gene encoding a key enzyme during abscisic acid (ABA) biosynthesis and ABA-regulated ethylene production in detached young persimmon calyx

Science Bulletin ◽

10.1007/s11434-009-0486-7 ◽

2009 ◽

Vol 54 (16) ◽

pp. 2830-2838 ◽

Cited By ~ 11

Author(s):

Ping Leng ◽

GuangLian Zhang ◽

XiangXin Li ◽

LiangHe Wang ◽

ZhongMing Zheng

Keyword(s):

Abscisic Acid ◽

Ethylene Production ◽

Gene Encoding ◽

Key Enzyme ◽

Nced Gene ◽

Aba Biosynthesis

Download Full-text

Characterization of Interactions between the Soybean Salt-Stress Responsive Membrane-Intrinsic Proteins GmPIP1 and GmPIP2

Agronomy ◽

10.3390/agronomy11071312 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1312

Author(s):

Jia Liu ◽

Weicong Qi ◽

Haiying Lu ◽

Hongbo Shao ◽

Dayong Zhang

Keyword(s):

Plasma Membrane ◽

Salt Stress ◽

Salt Tolerance ◽

Expression Profiles ◽

Expression Patterns ◽

Gene Expression Profiles ◽

Early Gene ◽

Plant Responses ◽

Constitutive Overexpression ◽

Important Trait

Salt tolerance is an important trait in soybean cultivation and breeding. Plant responses to salt stress include physiological and biochemical changes that affect the movement of water across the plasma membrane. Plasma membrane intrinsic proteins (PIPs) localize to the plasma membrane and regulate the water and solutes flow. In this study, quantitative real-time PCR and yeast two-hybridization were engaged to analyze the early gene expression profiles and interactions of a set of soybean PIPs (GmPIPs) in response to salt stress. A total of 20 GmPIPs-encoding genes had varied expression profiles after salt stress. Among them, 13 genes exhibited a downregulated expression pattern, including GmPIP1;6, the constitutive overexpression of which could improve soybean salt tolerance, and its close homologs GmPIP1;7 and 1;5. Three genes showed upregulated patterns, including the GmPIP1;6 close homolog GmPIP1;4, when four genes with earlier increased and then decreased expression patterns. GmPIP1;5 and GmPIP1;6 could both physically interact strongly with GmPIP2;2, GmPIP2;4, GmPIP2;6, GmPIP2;8, GmPIP2;9, GmPIP2;11, and GmPIP2;13. Definite interactions between GmPIP1;6 and GmPIP1;7 were detected and GmPIP2;9 performed homo-interaction. The interactions of GmPIP1;5 with GmPIP2;11 and 2;13, GmPIP1;6 with GmPIP2;9, 2;11 and GmPIP2;13, and GmPIP2;9 with itself were strengthened upon salt stress rather than osmotic stress. Taken together, we inferred that GmPIP1 type and GmPIP2 type could associate with each other to synergistically function in the plant cell; a salt-stress environment could promote part of their interactions. This result provided new clues to further understand the soybean PIP–isoform interactions, which lead to potentially functional homo- and heterotetramers for salt tolerance.

Download Full-text

The Craterostigma plantagineum protein kinase CpWAK1 interacts with pectin and integrates different environmental signals in the cell wall

Planta ◽

10.1007/s00425-021-03609-0 ◽

2021 ◽

Vol 253 (5) ◽

Author(s):

Peilei Chen ◽

Valentino Giarola ◽

Dorothea Bartels

Keyword(s):

Cell Wall ◽

Stress Responses ◽

Expression Profiles ◽

Phylogenetic Analyses ◽

Cell Wall Protein ◽

Biological Processes ◽

Environmental Signals ◽

High Affinity ◽

Craterostigma Plantagineum ◽

Receptor Kinases

Abstract Main conclusion The cell wall protein CpWAK1 interacts with pectin, participates in decoding cell wall signals, and induces different downstream responses. Abstract Cell wall-associated protein kinases (WAKs) are transmembrane receptor kinases. In the desiccation-tolerant resurrection plant Craterostigma plantagineum, CpWAK1 has been shown to be involved in stress responses and cell expansion by forming a complex with the C. plantagineum glycine-rich protein1 (CpGRP1). This prompted us to extend the studies of WAK genes in C. plantagineum. The phylogenetic analyses of WAKs from C. plantagineum and from other species suggest that these genes have been duplicated after species divergence. Expression profiles indicate that CpWAKs are involved in various biological processes, including dehydration-induced responses and SA- and JA-related reactions to pathogens and wounding. CpWAK1 shows a high affinity for “egg-box” pectin structures. ELISA assays revealed that the binding of CpWAKs to pectins is modulated by CpGRP1 and it depends on the apoplastic pH. The formation of CpWAK multimers is the prerequisite for the CpWAK–pectin binding. Different pectin extracts lead to opposite trends of CpWAK–pectin binding in the presence of Ca2+ at pH 8. These observations demonstrate that CpWAKs can potentially discriminate and integrate cell wall signals generated by diverse stimuli, in concert with other elements, such as CpGRP1, pHapo, Ca2+[apo], and via the formation of CpWAK multimers.

Download Full-text

A Screen for Genes That Function in Abscisic Acid Signaling in Arabidopsis thaliana

Genetics ◽

10.1093/genetics/161.3.1247 ◽

2002 ◽

Vol 161 (3) ◽

pp. 1247-1255 ◽

Cited By ~ 1

Author(s):

Eiji Nambara ◽

Masaharu Suzuki ◽

Suzanne Abrams ◽

Donald R McCarty ◽

Yuji Kamiya ◽

...

Keyword(s):

Abscisic Acid ◽

Growth And Development ◽

Plant Hormone ◽

The Other ◽

Aba Signaling ◽

Wild Type ◽

Plant Growth And Development ◽

Diverse Range ◽

Abscisic Acid Signaling ◽

Aba Insensitive

Abstract The plant hormone abscisic acid (ABA) controls many aspects of plant growth and development under a diverse range of environmental conditions. To identify genes functioning in ABA signaling, we have carried out a screen for mutants that takes advantage of the ability of wild-type Arabidopsis seeds to respond to (−)-(R)-ABA, an enantiomer of the natural (+)-(S)-ABA. The premise of the screen was to identify mutations that preferentially alter their germination response in the presence of one stereoisomer vs. the other. Twenty-six mutants were identified and genetic analysis on 23 lines defines two new loci, designated CHOTTO1 and CHOTTO2, and a collection of new mutant alleles of the ABA-insensitive genes, ABI3, ABI4, and ABI5. The abi5 alleles are less sensitive to (+)-ABA than to (−)-ABA. In contrast, the abi3 alleles exhibit a variety of differences in response to the ABA isomers. Genetic and molecular analysis of these alleles suggests that the ABI3 transcription factor may perceive multiple ABA signals.

Download Full-text

Comparative expression profiles of maize genes from a water stress-specific cDNA macroarray in response to high-salinity, cold or abscisic acid

Plant Science ◽

10.1016/j.plantsci.2006.01.019 ◽

2006 ◽

Vol 170 (6) ◽

pp. 1125-1132 ◽

Cited By ~ 19

Author(s):

Jun Zheng ◽

Jinfeng Zhao ◽

Jinpeng Zhang ◽

Junjie Fu ◽

Mingyue Gou ◽

...

Keyword(s):

Abscisic Acid ◽

Water Stress ◽

High Salinity ◽

Expression Profiles ◽

Cdna Macroarray

Download Full-text

OsVDE, a xanthophyll cycle key enzyme, mediates abscisic acid biosynthesis and negatively regulates salinity tolerance in rice

Planta ◽

10.1007/s00425-021-03802-1 ◽

2021 ◽

Vol 255 (1) ◽

Author(s):

Xiaocui Wang ◽

Pengxu Ren ◽

Lingxiao Ji ◽

Bohua Zhu ◽

Guosheng Xie

Keyword(s):

Abscisic Acid ◽

Salinity Tolerance ◽

Xanthophyll Cycle ◽

Acid Biosynthesis ◽

Abscisic Acid Biosynthesis ◽

Key Enzyme

Download Full-text

Isolation and Characterization of a Mutant of the Marine Bacterium Alcanivorax borkumensis SK2 Defective in Lipid Biosynthesis

Applied and Environmental Microbiology ◽

10.1128/aem.02832-09 ◽

2010 ◽

Vol 76 (9) ◽

pp. 2884-2894 ◽

Cited By ~ 10

Author(s):

Efraín Manilla-Pérez ◽

Alvin Brian Lange ◽

Stephan Hetzler ◽

Marc Wältermann ◽

Rainer Kalscheuer ◽

...

Keyword(s):

Carbon Source ◽

Sole Carbon Source ◽

Marine Bacterium ◽

Neutral Lipids ◽

Nile Red ◽

Dry Weight ◽

Wax Ester ◽

Gene Encoding ◽

Isolation And Characterization ◽

Key Enzyme

ABSTRACT In many microorganisms, the key enzyme responsible for catalyzing the last step in triacylglycerol (TAG) and wax ester (WE) biosynthesis is an unspecific acyltransferase which is also referred to as wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT; AtfA). The importance and function of two AtfA homologues (AtfA1 and AtfA2) in the biosynthesis of TAGs and WEs in the hydrocarbon-degrading marine bacterium Alcanivorax borkumensis SK2 have been described recently. However, after the disruption of both the AtfA1 and AtfA2 genes, reduced but substantial accumulation of TAGs was still observed, indicating the existence of an alternative TAG biosynthesis pathway. In this study, transposon-induced mutagenesis was applied to an atfA1 atfA2 double mutant to screen for A. borkumensis mutants totally defective in biosynthesis of neutral lipids in order to identify additional enzymes involved in the biosynthesis of these lipids. At the same time, we have searched for a totally TAG-negative mutant in order to study the function of TAGs in A. borkumensis. Thirteen fluorescence-negative mutants were identified on Nile red ONR7a agar plates and analyzed for their abilities to synthesize lipids. Among these, mutant 2 M131 was no longer able to synthesize and accumulate TAGs if pyruvate was used as the sole carbon source. The transposon insertion was localized in a gene encoding a putative cytochrome c family protein (ABO_1185). Growth and TAG accumulation experiments showed that the disruption of this gene resulted in the absence of TAGs in 2 M131 but that growth was not affected. In cells of A. borkumensis SK2 grown on pyruvate as the sole carbon source, TAGs represented about 11% of the dry weight of the cells, while in the mutant 2 M131, TAGs were not detected by thin-layer and gas chromatography analyses. Starvation and lipid mobilization experiments revealed that the lipids play an important role in the survival of the cells. The function of neutral lipids in A. borkumensis SK2 is discussed.

Download Full-text