Intronic T-DNA insertion in Arabidopsis<i>NBR1</i>conditionally affects wild-type transcript level

Wawrzyńska, Anna; Sirko, Agnieszka

doi:10.4161/15592324.2014.975659

Cited by 10 publications

(6 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These T-DNA insertions dramatically decreased full-length NBR1 protein accumulation (Figure 7(c)); however, the anti-NBR1 antibody was generated to the C-terminal UBA domain [14] and would not detect any N-terminal fragments of the protein that might accumulate in the mutants. Because intronic T-DNAs are sometimes removed by splicing [68,69], we characterized both intronic (nbr1-1) and exonic (nbr1-4) insertional mutants of NBR1 in combination with lon2-2. Both lon2 nbr1 double mutants resembled lon2-2 and did not form lateral roots in response to IBA (Figure 7(b)).…”

Section: Loss Of Atg11 Partially Suppresses Lon2 Defectsmentioning

confidence: 99%

A facile forward-genetic screen forArabidopsisautophagy mutants reveals twenty-one loss-of-function mutations disrupting sixATGgenes

et al. 2019

View full text Add to dashboard Cite

Macroautophagy is a process through which eukaryotic cells degrade large substrates including organelles, protein aggregates, and invading pathogens. Over 40 autophagy-related (ATG) genes have been identified through forward-genetic screens in yeast. Although homology-based analyses have identified conserved ATG genes in plants, only a few atg mutants have emerged from forward-genetic screens in Arabidopsis thaliana. We developed a screen that consistently recovers Arabidopsis atg mutations by exploiting mutants with defective LON2/At5g47040, a protease implicated in peroxisomal quality control. Arabidopsis lon2 mutants exhibit reduced responsiveness to the peroxisomally-metabolized auxin precursor indole-3-butyric acid (IBA), heightened degradation of several peroxisomal matrix proteins, and impaired processing of proteins harboring N-terminal peroxisomal targeting signals; these defects are ameliorated by preventing autophagy. We optimized a lon2 suppressor screen to expedite recovery of additional atg mutants. After screening mutagenized lon2-2 seedlings for restored IBA responsiveness, we evaluated stabilization and processing of peroxisomal proteins, levels of several ATG proteins, and levels of the selective autophagy receptor NBR1/At4g24690, which accumulates when autophagy is impaired. We recovered 21 alleles disrupting 6 ATG genes: ATG2/At3g19190, ATG3/At5g61500, ATG5/ At5g17290, ATG7/At5g45900, ATG16/At5g50230, and ATG18a/At3g62770. Twenty alleles were novel, and 3 of the mutated genes lack T-DNA insertional alleles in publicly available repositories. We also demonstrate that an insertional atg11/At4g30790 allele incompletely suppresses lon2 defects. Finally, we show that NBR1 is not necessary for autophagy of lon2 peroxisomes and that NBR1 overexpression is not sufficient to trigger autophagy of seedling peroxisomes, indicating that Arabidopsis can use an NBR1independent mechanism to target peroxisomes for autophagic degradation.

show abstract

Section: Loss Of Atg11 Partially Suppresses Lon2 Defectsmentioning

confidence: 99%

A facile forward-genetic screen forArabidopsisautophagy mutants reveals twenty-one loss-of-function mutations disrupting sixATGgenes

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Although T-DNA insertion mutants are usually very stable, the use of intronic insertion lines can be problematic. It was shown that different environmental stimuli can cause alternative splicing of introns leading to a loss of the T-DNA insertion and, thus, to a wild type-like expression of the gene [ 33 , 34 ]. In order to examine whether herbivory by S .…”

Section: Resultsmentioning

confidence: 99%

Herbivory-responsive calmodulin-like protein CML9 does not guide jasmonate-mediated defenses in Arabidopsis thaliana

et al. 2018

View full text Add to dashboard Cite

Calcium is an important second messenger in plants that is released into the cytosol early after recognition of various environmental stimuli. Decoding of such calcium signals by calcium sensors is the key for the plant to react appropriately to each stimulus. Several members of Calmodulin-like proteins (CMLs) act as calcium sensors and some are known to mediate both abiotic and biotic stress responses. Here, we study the role of the Arabidopsis thaliana CML9 in different stress responses. CML9 was reported earlier as defense regulator against Pseudomonas syringae. In contrast to salicylic acid-mediated defense against biotrophic pathogens such as P. syringae, defenses against herbivores and necrotrophic fungi are mediated by jasmonates. We demonstrate that CML9 is induced upon wounding and feeding of the insect herbivore Spodoptera littoralis. However, neither different CML9 loss-of-function mutant lines nor overexpression lines were impaired upon insect feeding. No difference in herbivore-induced phytohormone elevation was detected in cml9 lines. The defense against the spider mite Tetranychus urticae was also unaffected. In addition, cml9 mutant lines showed a wild type-like reaction to the necrotrophic fungus Alternaria brassicicola. Thus, our data suggest that CML9 might be a regulator involved only in the defense against biotrophic pathogens, independent of jasmonates. In addition, our data challenge the involvement of CML9 in plant drought stress response. Taken together, we suggest that CML9 is a specialized rather than a general regulator of stress responses in Arabidopsis.

show abstract

“…Relative differences in the activities of nev mutant proteins may impact the ratio of HAE/HSL2 receptors trapped in the endosomal compartments and thereby influence the ease of cst-2 mediated suppression ( Figure 1B ). While a truncated nev-6 mutant protein without an ARF GAP domain would not be expected to retain more function than the nev-2 mutant protein ( Figure 1 ), intronic T-DNA insertions can be spliced out in a fraction of the transcripts produced, leading to synthesis of functional protein ( Chehab et al, 2011 ; Rodriguez et al, 2014 ). Although we did not detect notable levels of correctly spliced NEV transcripts in nev-6 flowers ( Supplementary Figure S1A ), it is likely that even a small amount of functional protein is sufficient to promote abscission.…”

Section: Discussionmentioning

confidence: 99%

Allele-Specific Interactions between CAST AWAY and NEVERSHED Control Abscission in Arabidopsis Flowers

et al. 2016

View full text Add to dashboard Cite

An advantage of analyzing abscission in genetically tractable model plants is the ability to make use of classic genetic tools such as suppression analysis. We have investigated the regulation of organ abscission by carrying out suppression analysis in Arabidopsis flowers. Plants carrying mutations in the NEVERSHED (NEV) gene, which encodes an ADP-ribosylation factor GTPase-activating protein, retain their outer floral organs after fertilization. Mutant alleles of CAST AWAY (CST), which encodes a receptor-like cytoplasmic kinase, were found to restore organ abscission in nev flowers in an allele-specific manner. To further explore the basis of the interactions between CST and NEV, we tested whether the site of a nev mutation is predictive of its ability to be suppressed. Our results suggest instead that the strength of a nev allele influences whether organ abscission can be rescued by a specific allele of CST.

show abstract

Intronic T-DNA insertion in ArabidopsisNBR1conditionally affects wild-type transcript level

Cited by 10 publications

References 16 publications

A facile forward-genetic screen forArabidopsisautophagy mutants reveals twenty-one loss-of-function mutations disrupting sixATGgenes

A facile forward-genetic screen forArabidopsisautophagy mutants reveals twenty-one loss-of-function mutations disrupting sixATGgenes

Herbivory-responsive calmodulin-like protein CML9 does not guide jasmonate-mediated defenses in Arabidopsis thaliana

Allele-Specific Interactions between CAST AWAY and NEVERSHED Control Abscission in Arabidopsis Flowers

Contact Info

Product

Resources

About