Characterizing the role of endocarp and cells layers during pod (silique) development in Brassicaceae.

The process of silique dehiscence is essential for the proper dispersal of seeds at the end of a dehiscent fruit plants lifecycle. Current research focuses on genetic manipulation to mitigate this process and enhance shatter tolerance in crop plants, which has significant economic implications. In this study, we have conducted a time-course analysis of cell patterning and development in valve tissues of and closely related Triangle of U species (, , and ) from Brassicaceae.

Plant growth regulator extracts from seaweeds promote plant growth and confer drought tolerance in canola ().

, commonly known as canola, is an important oilseed crop in Canada contributing over $29.9 billion CAD to the Canadian economy annually. A major challenge facing Canadian canola is drought, which has become increasingly prevalent in recent years due to the changing climate.

Plant reproduction: Stigma receptors regulate reactive oxygen species to establish pollination barriers.

Exciting new research highlights how stigmatic receptors purposed for recognizing self-incompatible pollen interact with the FERONIA pathway to regulate stigmatic reactive oxygen species production to enforce a barrier against self-, intra- and interspecific pollen.

Identification of Arabidopsis Protein Kinases That Harbor Functional Type 1 Peroxisomal Targeting Signals.

Peroxisomes are eukaryotic specific organelles that perform diverse metabolic functions including fatty acid β-oxidation, reactive species metabolism, photorespiration, and responses to stress. However, the potential regulation of these functions by post-translational modifications, including protein phosphorylation, has had limited study. Recently, we identified and catalogued a large number of peroxisomal phosphorylated proteins, implicating the presence of protein kinases in this organelle.

Stylar steroids: Brassinosteroids regulate pistil development and self-incompatibility in Primula.

Manipulation of active brassinosteroid content in the developing flower of Primula dictates style length and female incompatibility type. A new study reveals the dual effects of brassinosteroids on establishing both the morphology of the pistil and mate recognition in self-incompatible heterostylous Primula forbseii.

Cell-cell signaling during the Brassicaceae self-incompatibility response.

Self-incompatibility (SI) is a mechanism that many plant families employ to prevent self-fertilization. In the Brassicaceae, the S-haplotype-specific interaction of the pollen-borne ligand, and a stigma-specific receptor protein kinase triggers a signaling cascade that culminates in the rejection of self-pollen. While the upstream molecular components at the receptor level of the signaling pathway have been extensively studied, the intracellular responses beyond receptor activation were not as well understood.

Identification and characterization of a female gametophyte defect in heterozygotes of .

Successful reproduction in angiosperms is dependent on the highly synchronous development of their male and female gametophytes and the ensuing fusion of the gametes from these reproductive tissue types. When crossing a T-DNA insertion line (Salk_024564), one of the S-domain receptor kinases involved in ABA responses with a fast neutron deletion line , the F1 heterozygotes ( +/-) displayed 50% ovule abortion suggesting a likely gametophytic defects. We identified and characterized an early stage female gametophyte developmental defect in the heterozygous mutant ovules.

Spatial regulation of alpha-galactosidase activity and its influence on raffinose family oligosaccharides during seed maturation and germination in .

Alpha-galactosides or Raffinose Family Oligosaccharides (RFOs) are enriched in legumes and are considered as anti-nutritional factors responsible for inducing flatulence. Due to a lack of alpha-galactosidases in the stomachs of humans and other monogastric animals, these RFOs are not metabolized and are passed to the intestines to be processed by gut bacteria leading to distressing flatulence. In plants, alpha(α)-galactosides are involved in desiccation tolerance during seed maturation and act as a source of stored energy utilized by germinating seeds.

A Flower-Specific Phospholipase D Is a Stigmatic Compatibility Factor Targeted by the Self-Incompatibility Response in Brassica napus.

Self-incompatibility (SI) is a genetic mechanism in hermaphroditic flowers that prevents inbreeding by rejection of self-pollen, while allowing cross- or genetically diverse pollen to germinate on the stigma to successfully fertilize the ovules. In Brassica, SI is initiated by the allele-specific recognition of pollen-encoded, secreted ligand (SCR/SP11) by the stigmatic receptor kinase S-locus receptor kinase (SRK), resulting in activation of SRK through phosphorylation [1-3]. Once activated, this phospho-relay converges on intracellular compatibility factors, which are immediately targeted for degradation by the E3 ligase, ARC1, resulting in the pollen rejection response [4, 5].

Nucleus- and plastid-targeted annexin 5 promotes reproductive development in Arabidopsis and is essential for pollen and embryo formation.

Background: Pollen development is a strictly controlled post-meiotic process during which microspores differentiate into microgametophytes and profound structural and functional changes occur in organelles. Annexin 5 is a calcium- and lipid-binding protein that is highly expressed in pollen grains and regulates pollen development and physiology. To gain further insights into the role of ANN5 in Arabidopsis development, we performed detailed phenotypic characterization of Arabidopsis plants with modified ANN5 levels.

Abiotic Stress Signaling in Wheat - An Inclusive Overview of Hormonal Interactions During Abiotic Stress Responses in Wheat.

Rapid global warming directly impacts agricultural productivity and poses a major challenge to the present-day agriculture. Recent climate change models predict severe losses in crop production worldwide due to the changing environment, and in wheat, this can be as large as 42 Mt/°C rise in temperature. Although wheat occupies the largest total harvested area (38.

Integration of amplification efficiency in qPCR analysis allows precise and relative quantification of transcript abundance of genes from large gene families using RNA isolated from difficult tissues.

The performance of the quantitative polymerase chain reaction (qPCR) assay in the analysis of gene expression belonging to multigene families in tissues rich in secondary metabolites is technically complicated. Here, we present the qPCR analysis of PMT2 gene, a predominant member of a multigene family from tobacco, expressed in the root tissues and is involved in the biosynthesis of nicotine. Consequently, we provide insight into the effect of polymerase chain reaction (PCR) amplification efficiency (AE) of reference and target genes of calibrator and test samples on the qPCR assay performance.

Farnesylation-mediated subcellular localization is required for CYP85A2 function.

Protein farnesylation refers to the addition of a 15-carbon farnesyl isoprenoid to the cysteine residue of the CaaX motif at the carboxy terminus of target proteins. In spite of its known roles in plant development and abiotic stress tolerance, how these processes are precisely regulated by farnesylation had remained elusive. We recently showed that CYP85A2, the cytochrome P450, which converts castasterone to brassinolide in the last step of brassinosteroid synthesis must be farnesylated in order to function in this pathway.

Glyoxalase Goes Green: The Expanding Roles of Glyoxalase in Plants.

The ubiquitous glyoxalase enzymatic pathway is involved in the detoxification of methylglyoxal (MG), a cytotoxic byproduct of glycolysis. The glyoxalase system has been more extensively studied in animals versus plants. Plant glyoxalases have been primarily associated with stress responses and their overexpression is known to impart tolerance to various abiotic stresses.

Activation of Mitochondrial Protein Phosphatase SLP2 by MIA40 Regulates Seed Germination.

Reversible protein phosphorylation catalyzed by protein kinases and phosphatases represents the most prolific and well-characterized posttranslational modification known. Here, we demonstrate that Arabidopsis (Arabidopsis thaliana) Shewanella-like protein phosphatase 2 (AtSLP2) is a bona fide Ser/Thr protein phosphatase that is targeted to the mitochondrial intermembrane space (IMS) where it interacts with the mitochondrial oxidoreductase import and assembly protein 40 (AtMIA40), forming a protein complex. Interaction with AtMIA40 is necessary for the phosphatase activity of AtSLP2 and is dependent on the formation of disulfide bridges on AtSLP2.

Farnesylation mediates brassinosteroid biosynthesis to regulate abscisic acid responses.

Protein farnesylation is a post-translational modification involving the addition of a 15-carbon farnesyl isoprenoid to the carboxy terminus of select proteins(1-3). Although the roles of this lipid modification are clear in both fungal and animal signalling, many of the mechanistic functions of farnesylation in plant signalling are still unknown. Here, we show that CYP85A2, the cytochrome P450 enzyme that performs the last step in brassinosteroid biosynthesis (conversion of castasterone to brassinolide)(4), must be farnesylated to function in Arabidopsis.

Identification of detoxification pathways in plants that are regulated in response to treatment with organic compounds isolated from oil sands process-affected water.

Bitumen mining in the Athabasca oil sands region of northern Alberta results in the accumulation of large volumes of oil sands process-affected water (OSPW). The acid-extractable organic (AEO) fraction of OSPW contains a variety of compounds, including naphthenic acids, aromatics, and sulfur- and nitrogen-containing compounds that are toxic to aquatic and terrestrial organisms. We have studied the effect of AEO treatment on the transcriptome of root and shoot tissues in seedlings of the model plant, Arabidopsis thaliana.

A proposed role for selective autophagy in regulating auxin-dependent lateral root development under phosphate starvation in Arabidopsis.

Plants respond to limited soil nutrient availability by inducing more lateral roots (LR) to increase the root surface area. At the cellular level, nutrient starvation triggers the process of autophagy through which bulk degradation of cellular materials is achieved to facilitate nutrient mobilization. Whether there is any link between the cellular autophagy and induction of LR had remained unknown.

Degradation of glyoxalase I in Brassica napus stigma leads to self-incompatibility response.

Self-incompatibility (rejection of 'self'-pollen) is a reproductive barrier that allows hermaphroditic flowering plants to prevent inbreeding, to promote outcrossing and hybrid vigour. The self-incompatibility response in Brassica involves allele-specific interaction between the pollen small cysteine-rich, secreted protein ligand (SCR/SP11) and the stigmatic S-receptor kinase (SRK), which leads to the activation of the E3 ubiquitin ligase ARC1 (Armadillo repeat-containing 1), resulting in proteasomal degradation of compatibility factors needed for successful pollination. Despite this, targets of ARC1 and the intracellular signalling network that is regulated by these targets, have remained elusive.

The ARC1 E3 ligase promotes a strong and stable self-incompatibility response in Arabidopsis species: response to the Nasrallah and Nasrallah commentary.

Following the identification of the male (S-locus Cysteine Rich/S-locus Protein 11) and female (S Receptor kinase [SRK]) factors controlling self-incompatibility in the Brassicaceae, research in this field has focused on understanding the nature of the cellular responses activated by these regulators. We previously identified the ARM Repeat Containing1 (ARC1) E3 ligase as a component of the SRK signaling pathway and demonstrated ARC1's requirement in the stigma for self-incompatible pollen rejection in Brassica napus, Arabidopsis lyrata, and Arabidopsis thaliana. Here, we discuss our findings on the role of ARC1 in reconstructing a strong and stable A.