Publications (3)6.53 Total impact
Article: Arabidopsis basic leucine-zipper transcription factors TGA9 and TGA10 interact with floral glutaredoxins ROXY1 and ROXY2 and are redundantly required for anther development.[show abstract] [hide abstract]
ABSTRACT: ROXY1 and ROXY2 are CC-type floral glutaredoxins with redundant functions in Arabidopsis (Arabidopsis thaliana) anther development. We show here that plants lacking the basic leucine-zipper transcription factors TGA9 and TGA10 have defects in male gametogenesis that are strikingly similar to those in roxy1 roxy2 mutants. In tga9 tga10 mutants, adaxial and abaxial anther lobe development is differentially affected, with early steps in anther development blocked in adaxial lobes and later steps affected in abaxial lobes. Distinct from roxy1 roxy2, microspore development in abaxial anther lobes proceeds to a later stage with the production of inviable pollen grains contained within nondehiscent anthers. Histological analysis shows multiple defects in the anther dehiscence program, including abnormal stability and lignification of the middle layer and defects in septum and stomium function. Compatible with these defects, TGA9 and TGA10 are expressed throughout early anther primordia but resolve to the middle and tapetum layers during meiosis of pollen mother cells. Several lines of evidence suggest that ROXY promotion of anther development is mediated in part by TGA9 and TGA10. First, TGA9 and TGA10 expression overlaps with ROXY1/2 during anther development. Second, TGA9/10 and ROXY1/2 operate downstream of SPOROCYTELESS/NOZZLE, where they positively regulate a common set of genes that contribute to tapetal development. Third, TGA9 and TGA10 directly interact with ROXY proteins in yeast and in plant cell nuclei. These findings suggest that activation of TGA9/10 transcription factors by ROXY-mediated modification of cysteine residues promotes anther development, thus broadening our understanding of how redox-regulated TGA factors function in plants.Plant physiology 11/2010; 154(3):1492-504. · 6.53 Impact Factor
Article: Conservation of NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 function between Arabidopsis thaliana and Brassica napus[show abstract] [hide abstract]
ABSTRACT: An Expressed Sequence Tag encoding a protein highly related to Arabidopsis NPR1 was isolated from canola quality Brassica napus. The protein, BnNPR1, interacts with the same spectrum of TGA transcription factors and NIMIN proteins as AtNPR1 in the yeast two-hybrid system. When expressed in Arabidopsis npr1 mutants, BnNPR1 restored salicylic acid-dependent expression of the marker gene PR-1 and enhanced basal defense as well as systemic acquired resistance against a virulent strain of the bacterial pathogen Pseudomonas syringae. Expression of Arabidopsis NPR1 or over expression of BnNPR1 in transgenic B. napus also effectively enhanced basal resistance against P. syringae.Physiological and Molecular Plant Pathology.
Article: Analysis of the DRR230 family of pea defensins: gene expression pattern and evidence of broad host-range antifungal activity[show abstract] [hide abstract]
ABSTRACT: A new member of the pea (Pisum sativum L.) defensin gene family (DRR230-c) was isolated and characterized. In the absence of pathogen infection, transcripts from this gene and that encoding a related defensin (DRR230-a) were detected at a relatively high level in several tissues with the exception of immature pods. Expression of these genes was activated in young pods, and further elevated in mature foliar tissues, following challenge with the fungal pathogen Ascochyta pinodes, as well as with compatible, incompatible and non-host races of the bacterial pathogen Pseudomonas syringae. Induction of the defensin genes paralleled that of several known pathogenesis-related genes, including a PR-10 homolog and β-1, 3-glucanase. Pathogen-induced defensin gene activation appeared to occur only in the infected tissues, and not systemically throughout the plant. Transgenic tobacco plants expressing either of the two pea defensin genes under the control of the cauliflower mosaic virus 35S promoter were generated. When compared to partially purified peptide extracts from untransformed tobacco plants, those from transgenic plants possessed a significantly higher potential to reduce the growth of several phytopathogenic fungi in vitro.Plant Science.