Wheat type one protein phosphatase promotes salt and osmotic stress tolerance in arabidopsis via auxin-mediated remodelling of the root system.

The control of optimal root growth and plant stress responses depends largely on a variety of phytohormones among which auxin and brassinosteroids (BRs) are the most influential. We have previously reported that the durum wheat type 1 protein phosphatase TdPP1 participates in the control of root growth by modulating BR signaling. In this study, we pursue our understanding of how TdPP1 fulfills this regulatory function on root growth by evaluating the physiological and molecular responses of Arabidopsis TdPP1 over-expressing lines to abiotic stresses.

Genome-wide characterization and expression profiling of GASA gene family in Triticum turgidum ssp. durum (desf.) husn. (Durum wheat) unveils its involvement in environmental stress responses.

Family members within the plant-specific gibberellic acid-stimulated Arabidopsis (GASA) gene serve a crucial role in plant growth and development, particularly in flower induction and seed development. Through a genome-wide analysis of Triticum turgidum ssp. Durum (durum wheat), we identified 19 GASA genes, designated as TdGASA1‒19.

Characterization of Siccibacter sp. Strain C2 a Novel Rhizobacterium that Enhances Tolerance of Barley to Salt Stress.

Plant growth promoting rhizobacteria (PGPR) arouse an increasing interest as an eco-friendly solution for improving crop tolerance to environmental stresses. In this study, we report the characterization of a novel halotolerant PGPR strain (named C2) identified in a screen of rhizospheric bacterial isolates from southeast of Tunisia. Phylogenetic analysis showed that strain C2 is most likely affiliated to the genus Siccibacter with Siccibacter turicensis as the closest species (98.

Wheat Type One Protein Phosphatase Participates in the Brassinosteroid Control of Root Growth via Activation of BES1.

Brassinosteroids (BRs) play key roles in diverse plant growth processes through a complex signaling pathway. Components orchestrating the BR signaling pathway include receptors such as kinases, transcription factors, protein kinases and phosphatases. The proper functioning of the receptor kinase BRI1 and the transcription factors BES1/BZR1 depends on their dephosphorylation by type 2A protein phosphatases (PP2A).

Genomic analysis of intrinsically disordered proteins in cereals: From mining to meaning.

Intrinsically disordered proteins (IDPs) are highly abundant in eukaryotic proteomes and involved in key biological and cellular processes. Although some resources of disordered protein predictions are available from animal and plant proteomes, those related to cereals are largely unknown. Here, we present an overview of IDPomes from Oryza sativa, Zea mays, Sorghum bicolor and Brachypodium distachyon.

Differential regulation of the durum wheat MAPK phosphatase 1 by calmodulin, bivalent cations and possibly mitogen activated protein kinase 3.

MAPK phosphatases (MKPs) are relevant negative regulators of MAPKs in eukaryotes as they mediate the feedback control of MAPK cascades in multiple cellular processes. Despite their relevance, our knowledge on the role of cereal MKPs in stress tolerance is scarce and TMKP1 remains today the only studied MKP in wheat. TMKP1 was previously reported to be involved in plant salt stress tolerance.

The wheat TdRL1 is the functional homolog of the rice RSS1 and promotes plant salt stress tolerance.

Rice rss1 complementation assays show that wheat TdRL1 and RSS1 are true functional homologs. TdRL1 over-expression in Arabidopsis conferred salt stress tolerance and alleviated ROS accumulation. Plants have developed highly flexible adaptive responses to their ever-changing environment, which are often mediated by intrinsically disordered proteins (IDP).

Characterization of wheat (Triticum aestivum) TIFY family and role of Triticum Durum TdTIFY11a in salt stress tolerance.

The TIFY proteins constitute a plant-specific super-family and they are involved in regulating many plant processes, such as development, defences and stress responses. The Jasmonate-ZIM-Domain (JAZ) proteins, the best-characterized sub-group of the TIFY family are key regulator of the jasmonic acid (JA) signalling pathway. Jasmonates regulate several aspects of plant development, and play a primary role in defence mechanisms as well as in plant responses to abiotic stresses.

Genome wide identification of wheat and Brachypodium type one protein phosphatases and functional characterization of durum wheat TdPP1a.

Reversible phosphorylation is an essential mechanism regulating signal transduction during development and environmental stress responses. An important number of dephosphorylation events in the cell are catalyzed by type one protein phosphatases (PP1), which catalytic activity is driven by the binding of regulatory proteins that control their substrate specificity or subcellular localization. Plants harbor several PP1 isoforms accounting for large functional redundancies.

Regulation of the wheat MAP kinase phosphatase 1 by 14-3-3 proteins.

Plant MAP kinase phosphatases (MKPs) are major regulators of MAPK signaling pathways and play crucial roles in controlling growth, development and stress responses. The presence of several functional domains in plant MKPs such as a dual specificity phosphatase catalytic domain, gelsolin, calmodulin-binding and serine-rich domains, suggests that MKPs can interact with distinct cellular partners, others than MAPKs. In this report, we identified a canonical mode I 14-3-3-binding motif (KLPSLP) located at the carboxy-terminal region of the wheat MKP, TMKP1.

New Insights on Plant Salt Tolerance Mechanisms and Their Potential Use for Breeding.

Soil salinization is a major threat to agriculture in arid and semi-arid regions, where water scarcity and inadequate drainage of irrigated lands severely reduce crop yield. Salt accumulation inhibits plant growth and reduces the ability to uptake water and nutrients, leading to osmotic or water-deficit stress. Salt is also causing injury of the young photosynthetic leaves and acceleration of their senescence, as the Na cation is toxic when accumulating in cell cytosol resulting in ionic imbalance and toxicity of transpiring leaves.

The wheat MAP kinase phosphatase 1 alleviates salt stress and increases antioxidant activities in Arabidopsis.

Mitogen-activated protein kinase phosphatases (MKPs) are important negative regulators in the MAPK signaling pathways, which play crucial roles in plant growth, development and stress responses. We have previously shown that the heterologous expression of a durum wheat MKP, TMKP1, results in increased tolerance to salt stress in yeast but its particular contribution in salt stress tolerance in plants was not investigated. Here, TMKP1 was overexpressed in Arabidopsis thaliana and physiological changes were assessed in transgenic plants exposed to stress conditions.

Molecular and functional characterization of the durum wheat TdRL1, a member of the conserved Poaceae RSS1-like family that exhibits features of intrinsically disordered proteins and confers stress tolerance in yeast.

Because of their fixed lifestyle, plants must acclimate to environmental changes by orchestrating several responses ranging from protective measures to growth control. Growth arrest is observed upon abiotic stress and can cause penalties to plant production. But, the molecular interface between stress perception and cell cycle control is poorly understood.

Plant dehydrins and stress tolerance: versatile proteins for complex mechanisms.

Dehydrins (DHNs), or group 2 LEA (Late Embryogenesis Abundant) proteins, play a fundamental role in plant response and adaptation to abiotic stresses. They accumulate typically in maturing seeds or are induced in vegetative tissues following salinity, dehydration, cold, and freezing stress. The generally accepted classification of dehydrins is based on their structural features, such as the presence of conserved sequences, designated as Y, S, and K segments.

TMKP1 is a novel wheat stress responsive MAP Kinase phosphatase localized in the nucleus.

The regulation of plant signalling responses by Mitogen-Activated Protein Kinases (MAPKs)-mediated protein phosphorylation is well recognized. MAP kinase phosphatases (MKPs) are negative regulators of MAPKs in eukaryotes. We report here the identification and the characterization of TMKP1, the first wheat MKP (Triticum turgidum L.

Plant retinoblastoma homologues control nuclear proliferation in the female gametophyte.

Haploid spores of plants divide mitotically to form multicellular gametophytes. The female spore (megaspore) of most flowering plants develops by means of a well-defined programme into the mature megagametophyte consisting of the egg apparatus and a central cell. We investigated the role of the Arabidopsis retinoblastoma protein homologue and its function as a negative regulator of cell proliferation during megagametophyte development.