The Parasporal Body of subsp. : A Unique Phage Capsid-Associated Prokaryotic Insecticidal Organelle.

The three most important commercial bacterial insecticides are all derived from subspecies of (). Specifically, subsp. (Btk) and subsp.

Plant Proteases: From Key Enzymes in Germination to Allies for Fighting Human Gluten-Related Disorders.

Plant proteases play a crucial role in many different biological processes along the plant life cycle. One of the most determinant stages in which proteases are key protagonists is the plant germination through the hydrolysis and mobilization of other proteins accumulated in seeds and cereal grains. The most represented proteases in charge of this are the cysteine proteases group, including the C1A family known as papain-like and the C13 family also called legumains.

Phytoglobins in the nuclei, cytoplasm and chloroplasts modulate nitric oxide signaling and interact with abscisic acid.

Symbiotic hemoglobins provide O to N -fixing bacteria within legume nodules, but the functions of non-symbiotic hemoglobins or phytoglobins (Glbs) are much less defined. Immunolabeling combined with confocal microscopy of the Glbs tagged at the C-terminus with green fluorescent protein was used to determine their subcellular localizations in Arabidopsis and Lotus japonicus. Recombinant proteins were used to examine nitric oxide (NO) scavenging in vitro and transgenic plants to show S-nitrosylation and other in vivo interactions with NO and abscisic acid (ABA) responses.

Insights on the Proteases Involved in Barley and Wheat Grain Germination.

Seed storage proteins must be hydrolyzed by proteases to deliver the amino acids essential for embryo growth and development. Several groups of proteases involved in this process have been identified in both the monocot and the dicot species. This review focuses on the implication of proteases during germination in two cereal species, barley and wheat, where proteolytic control during the germination process has considerable economic importance.

Differential response of silencing HvIcy2 barley plants against Magnaporthe oryzae infection and light deprivation.

Background: Phytocystatins (PhyCys) act as endogenous regulators of cysteine proteases (CysProt) involved in various physiological processes. Besides, PhyCys are involved in plant reactions to abiotic stresses like drought or darkness and have been used as effective molecules against different pests and pathogens. The barley PhyCys-CysProt system is considered a model of protease-inhibitor regulation of protein turnover.

Overexpression of HvIcy6 in Barley Enhances Resistance against Tetranychus urticae and Entails Partial Transcriptomic Reprogramming.

Cystatins have been largely used for pest control against phytophagous species. However, cystatins have not been commonly overexpressed in its cognate plant species to test their pesticide capacity. Since the inhibitory role of barley HvCPI-6 cystatin against the phytophagous mite has been previously demonstrated, the purpose of our study was to determine if barley transgenic lines overexpressing its own gene were more resistant against this phytophagous infestation.

Silencing barley cystatins HvCPI-2 and HvCPI-4 specifically modifies leaf responses to drought stress.

Protein breakdown and mobilization are some of the major metabolic features associated with abiotic stresses, essential for nutrient recycling and plant survival. Genetic manipulation of protease and/or protease inhibitors may contribute to modulate proteolytic processes and plant responses. The expression analysis of the whole cystatin family, inhibitors of C1A cysteine proteases, after water deprivation in barley leaves highlighted the involvement of Icy-2 and Icy-4 cystatin genes.

HvPap-1 C1A Protease Participates Differentially in the Barley Response to a Pathogen and an Herbivore.

Co-evolutionary processes in plant-pathogen/herbivore systems indicate that protease inhibitors have a particular value in biotic interactions. However, little is known about the defensive role of their targets, the plant proteases. C1A cysteine proteases are the most abundant enzymes responsible for the proteolytic activity during different processes like germination, development and senescence in plants.

Vacuolar processing enzyme 4 contributes to maternal control of grain size in barley by executing programmed cell death in the pericarp.

The angiosperm embryo and endosperm are limited in space because they grow inside maternal seed tissues. The elimination of cell layers of the maternal seed coat by programmed cell death (PCD) could provide space and nutrition to the filial organs. Using the barley (Hordeum vulgare L.

Phytocystatins: Defense Proteins against Phytophagous Insects and Acari.

This review deals with phytocystatins, focussing on their potential role as defence proteins against phytophagous arthropods. Information about the evolutionary, molecular and biochemical features and inhibitory properties of phytocystatins are presented. Cystatin ability to inhibit heterologous cysteine protease activities is commented on as well as some approaches of tailoring cystatin specificity to enhance their defence function towards pests.

Threshold-dependent transcriptional discrimination underlies stem cell homeostasis.

Transcriptional mechanisms that underlie the dose-dependent regulation of gene expression in animal development have been studied extensively. However, the mechanisms of dose-dependent transcriptional regulation in plant development have not been understood. In Arabidopsis shoot apical meristems, WUSCHEL (WUS), a stem cell-promoting transcription factor, accumulates at a higher level in the rib meristem and at a lower level in the central zone where it activates its own negative regulator, CLAVATA3 (CLV3).

DNA-dependent homodimerization, sub-cellular partitioning, and protein destabilization control WUSCHEL levels and spatial patterning.

The homeodomain transcription factor WUSCHEL (WUS) promotes stem cell maintenance in inflorescence meristems of Arabidopsis thaliana WUS, which is synthesized in the rib meristem, migrates and accumulates at lower levels in adjacent cells. Maintenance of WUS protein levels and spatial patterning distribution is not well-understood. Here, we show that the last 63-aa stretch of WUS is necessary for maintaining different levels of WUS protein in the rib meristem and adjacent cells.

Plant senescence and proteolysis: two processes with one destiny.

Senescence-associated proteolysis in plants is a complex and controlled process, essential for mobilization of nutrients from old or stressed tissues, mainly leaves, to growing or sink organs. Protein breakdown in senescing leaves involves many plastidial and nuclear proteases, regulators, different subcellular locations and dynamic protein traffic to ensure the complete transformation of proteins of high molecular weight into transportable and useful hydrolysed products. Protease activities are strictly regulated by specific inhibitors and through the activation of zymogens to develop their proteolytic activity at the right place and at the proper time.

HvPap-1 C1A protease actively participates in barley proteolysis mediated by abiotic stresses.

Protein breakdown and mobilization from old or stressed tissues to growing and sink organs are some of the metabolic features associated with abiotic/biotic stresses, essential for nutrient recycling. The massive degradation of proteins implies numerous proteolytic events in which cysteine-proteases are the most abundant key players. Analysing the role of barley C1A proteases in response to abiotic stresses is crucial due to their impact on plant growth and grain yield and quality.

HvPap-1 C1A Protease and HvCPI-2 Cystatin Contribute to Barley Grain Filling and Germination.

Proteolysis is an essential process throughout the mobilization of storage proteins in barley (Hordeum vulgare) grains during germination. It involves numerous types of enzymes, with C1A Cys proteases the most abundant key players. Manipulation of the proteolytic machinery is a potential way to enhance grain yield and quality, and it could influence the mobilization of storage compounds along germination.

Inhibitory properties of cysteine protease pro-peptides from barley confer resistance to spider mite feeding.

C1A plant cysteine proteases are synthesized as pre-pro-enzymes that need to be processed to become active by the pro-peptide claves off from its cognate enzyme. These pro-sequences play multifunctional roles including the capacity to specifically inhibit their own as well as other C1A protease activities from diverse origin. In this study, it is analysed the potential role of C1A pro-regions from barley as regulators of cysteine proteases in target phytophagous arthropods (coleopteran and acari).

Plant protein peptidase inhibitors: an evolutionary overview based on comparative genomics.

Background: Peptidases are key proteins involved in essential plant physiological processes. Although protein peptidase inhibitors are essential molecules that modulate peptidase activity, their global presence in different plant species remains still unknown. Comparative genomic analyses are powerful tools to get advanced knowledge into the presence and evolution of both, peptidases and their inhibitors across the Viridiplantae kingdom.

C1A cysteine protease-cystatin interactions in leaf senescence.

Senescence-associated proteolysis in plants is a crucial process to relocalize nutrients from leaves to growing or storage tissues. The massive net degradation of proteins involves broad metabolic networks, different subcellular compartments, and several types of proteases and regulators. C1A cysteine proteases, grouped as cathepsin L-, B-, H-, and F-like according to their gene structures and phylogenetic relationships, are the most abundant enzymes responsible for the proteolytic activity during leaf senescence.

Intermolecular interaction between Cry2Aa and Cyt1Aa and its effect on larvicidal activity against Culex quinquefasciatus.

The Cyt1Aa protein of Bacillus thuringiensis susbp. israelensis elaborates demonstrable toxicity to mosquito larvae, but more importantly, it enhances the larvicidal activity of this species Cry proteins (Cry11Aa, Cry4Aa, and Cry4Ba) and delays the phenotypic expression of resistance to these that has evolved in Culex quinquefasciatus. It is also known that Cyt1Aa, which is highly lipophilic, synergizes Cry11Aa by functioning as a surrogate membrane-bound receptor for the latter protein.

Potato CONSTANS is involved in photoperiodic tuberization in a graft-transmissible manner.

CONSTANS (CO) is involved in the photoperiodic control of plant developmental processes, including flowering in several species and seasonal growth cessation and bud set in trees. It has been proposed that CO could also affect the day-length regulation of tuber induction in Solanum tuberosum (potato), a plant of great agricultural relevance. To address this question, we examined the role of CO in potato.

A 54-kilodalton protein encoded by pBtoxis is required for parasporal body structural integrity in Bacillus thuringiensis subsp. israelensis.

Strains of Bacillus thuringiensis such as B. thuringiensis subsp. israelensis (ONR-60A) and B.

Characterization of the entire cystatin gene family in barley and their target cathepsin L-like cysteine-proteases, partners in the hordein mobilization during seed germination.

Plant cystatins are inhibitors of cysteine-proteases of the papain C1A and legumain C13 families. Cystatin data from multiple plant species have suggested that these inhibitors act as defense proteins against pests and pathogens and as regulators of protein turnover. In this study, we characterize the entire cystatin gene family from barley (Hordeum vulgare), which contain 13 nonredundant genes, and identify and characterize their target enzymes, the barley cathepsin L-like proteases.

Carboxy terminal extended phytocystatins are bifunctional inhibitors of papain and legumain cysteine proteinases.

Plant legumains are cysteine proteinases putatively involved in processing endogenous proteins. Phytocystatins (PhyCys) have been described as plant inhibitors of papain-like cysteine proteinases. Some PhyCys contain a carboxy terminal extension with an amino acid motif (SNSL) similar to that involved in the inhibition of legumain-like proteins by human cystatins.

Proteolytic processing of native Cry1Ab toxin by midgut extracts and purified trypsins from the Mediterranean corn borer Sesamia nonagrioides.

The proteolytic processing of native Cry1Ab toxin by midgut extracts from the Mediterranean corn borer, Sesamia nonagrioides, takes place in successive steps. Several cuts occur until a 74 kDa protein is obtained; this is further digested to give rise to an active form of 69 kDa, which can be again processed to fragments of 67, 66 and 43 kDa. We have shown that three different trypsins (TI, TIIA and TIII) purified from the S.