Disease relevance of SNI1

• In addition to light-responsive genes, genes normally inducible by plant pathogens, hypoxia, and developmental programs were inappropriately expressed in these mutants [1].
• Characterization of an Arabidopsis cDNA for a soluble epoxide hydrolase gene that is inducible by auxin and water stress [2].
• All vectors were derived from pCambia T-DNA cloning vectors, with the exception of a chemically inducible vector, for Agrobacterium sp.-mediated transformation of a wide range of plant species [3].
• An HrpL-dependent promoter-trap assay was developed to screen genomic libraries of P. syringae strains for promoters whose activity in Escherichia coli is dependent on an inducible hrpL construct [4].
• On the other hand, we have recently shown that transgenic tobacco deficient in an inducible RdRP (NtRdRP1) activity became more susceptible to both Tobacco mosaic virus and Potato virus X [5].

High impact information on SNI1

• We cloned the SNI1 gene and found that it encodes a leucine-rich nuclear protein [6].
• In the npr1-1 background, the sni1 (suppressor of npr1-1, inducible 1) mutant shows near wild-type levels of PR1 expression and resistance to pathogens after induction [6].
• Inducible overexpression of GPA1 in Arabidopsis confers inducible ectopic cell division [7].
• Sequence comparison with orthologs in other plant species and a saturating NAAIRS-scanning mutagenesis of SNI1 identified regions in SNI1 that are required for its activity [8].
• Arabidopsis thaliana SNI1 (for Suppressor of NPR1, Inducible) is a negative regulator of SAR required to dampen the basal expression of PR genes [8].

Chemical compound and disease context of SNI1

• One of these clones (termed PAR-1 for photoassimilate-responsive) displayed features similar to pathogenesis-related proteins: Hybridizing transcripts, 1.2 and 1.0 kb in length, were strongly inducible by salicylate and accumulated in tobacco plants after infection with potato virus Y (PVY) both in infected and uninfected systemic leaves [9].
• Enzyme assays of inducible GUS activity in transgenic Arabidopsis and tobacco plants showed that GUS activity directed by both kin1 and cor6.6 promoters was significantly induced by ABA, dehydration and osmoticum, but not by low temperature [10].
• To facilitate the identification of the rate-limiting step(s) in the tocopherol biosynthetic pathway through the modulation of transgene expression, we established an inducible expression system in Synechocystis sp. strain PCC 6803 [11].

Biological context of SNI1

• We tested the dynamics of CLV3 signaling using an inducible gene expression system [12].
• In transgenic lines expressing the inducible AtPLC1 sense transgene, an increase in AtPLC1 expression was not sufficient to activate the expression of ABA-responsive genes in vegetative tissues [13].
• Plants with severe inducible phenotypes showed additional abnormality in cotyledon expansion [14].
• We conditionally downregulated gamma-tubulin by inducible expression of RNA interference (RNAi) constructs in Arabidopsis thaliana [15].
• Whole genome transcriptional profiling showed that in the sni1 mutant, Nonexpresser of PR genes (NPR1)-dependent benzothiadiazole S-methylester-responsive genes were specifically derepressed [8].

Anatomical context of SNI1

• First, we established a hypersensitive cell death assay for protoplasts using the membrane-impermeable, nuclear-staining dye, YO-PRO-1, and transgenic Arabidopsis plants that carry an inducible avrRpt2 gene [16].
• We have isolated a haploid cell line of N. plumbaginifolia, hNP 588, that is constitutive and not inducible for nitrate reductase [17].
• The results concur with previous studies showing a high-affinity NO3- transport system in Arabidopsis that is inducible following a period of nitrogen-limiting growth, but they underline the importance of voltage as a kinetic factor controlling NO3- transport at the plant plasma membrane [18].
• GUS assays and RNA blot analysis showed that expression of the OsCHLH gene is light inducible, while TEM analysis revealed that the thylakoid membrane of the mutant chloroplasts is underdeveloped [19].
• The PEN2 glycosyl hydrolase localizes to peroxisomes and acts as a component of an inducible preinvasion resistance mechanism [20].

Associations of SNI1 with chemical compounds

• We conclude that low-affinity systems of nitrate uptake, like high-affinity systems, are composed of inducible and constitutive components and that with their distinct functions, they are part of an elaborate nitrate uptake network in Arabidopsis [21].
• Expression of CBL9 was inducible by multiple stress signals and abscisic acid (ABA) in young seedlings [22].
• Expression of POLARIS is inducible by exogenous auxin and suppressed by cytokinin but is unaffected by inhibitors of polar auxin transport or cell division [23].
• In contrast to LeSUT1, which is induced during the sink-to-source transition of leaves, SUT2 is more highly expressed in sink than in source leaves and is inducible by sucrose [24].
• Concordant with this view, we have recently shown that the Arabidopsis thionin Thi2.1 gene is inducible by phytopathogenic fungi [25].

Regulatory relationships of SNI1

• CIP4 expression is light inducible and regulated by COP1 [26].

Other interactions of SNI1

• The Arabidopsis NPR1 gene is essential in activating systemic, inducible plant defense responses [27].
• The RPT2 gene is light inducible; encodes a novel protein with putative phosphorylation sites, a nuclear localization signal, a BTB/POZ domain, and a coiled-coil domain; and belongs to a large gene family that includes the recently isolated NPH3 gene [28].
• Constitutive and inducible over-expression of OBP2 activates expression of CYP83B1 [29].
• By contrast, inducible expression of miR164 in wild-type plants led to decreased NAC1 mRNA levels and reduced lateral root emergence [30].
• PHR1 is a single-copy gene and is not expressed in dark-grown etiolated seedlings: the message is light inducible, which is similar to the expression profile for photoreactivation activity in plants [31].

Analytical, diagnostic and therapeutic context of SNI1

• Chromatin immunoprecipitation indicated that histone modification may be involved in SNI1-mediated repression [8].
• We confirmed stress-inducible expression of the candidate genes selected by microarray analysis using RNA gel-blot analysis and finally identified a total of 73 genes as stress inducible including 58 novel unreported genes in rice [32].
• Dissection of the AtNRT2.1:AtNRT2.2 Inducible High-Affinity Nitrate Transporter Gene Cluster [33].
• RT-PCR analysis showed that the induction of transcripts for vegetative storage protein and lipoxygenase genes, previously shown to be inducible by wound and jasmonate application in the wild-type, was absent in the aos mutant [34].
• Using differential display PCR we have successfully been able to identify three clones that are inducible by touch and not by ethylene [35].

References