Proteomic Insights of Cowpea Response to Combined Biotic and Abiotic Stresses.

The co-occurrence of biotic and abiotic stresses in agricultural areas severely affects crop performance and productivity. Drought is one of the most adverse environmental stresses, and its association with root-knot nematodes further limits the development of several economically important crops, such as cowpea. Plant responses to combined stresses are complex and require novel adaptive mechanisms through the induction of specific biotic and abiotic signaling pathways. Therefore, the present work aimed to identify proteins involved in the resistance of cowpea to nematode and drought stresses individually and combined. We used the genotype CE 31, which is resistant to the root-knot nematode Meloidogyne spp. And tolerant to drought. Three biological replicates of roots and shoots were submitted to protein extraction, and the peptides were evaluated by LC-MS/MS. Shotgun proteomics revealed 2345 proteins, of which 1040 were differentially abundant. Proteins involved in essential biological processes, such as transcriptional regulation, cell signaling, oxidative processes, and photosynthesis, were identified. However, the main defense strategies in cowpea against cross-stress are focused on the regulation of hormonal signaling, the intense production of pathogenesis-related proteins, and the downregulation of photosynthetic activity. These are key processes that can culminate in the adaptation of cowpea challenged by multiple stresses. Furthermore, the candidate proteins identified in this study will strongly contribute to cowpea genetic improvement programs.

Stress and cell cycle regulation during somatic embryogenesis plays a key role in oil palm callus development.

Oil palm is an oleaginous plant of relevant economic importance since its fruits are rich in vegetable oil. These plants have a single apical meristem and the main method for vegetative propagation is somatic embryogenesis. The aim of this study was to identify differentially abundant proteins from oil palm genotypes contrasting in the capacity of embryogenic competence acquisition, using shotgun proteomics. Oil palm leaves were subjected to callus induction and the material was collected in biological triplicates at 14 and 90 days of callus induction. LC-MS/MS analysis was performed and revealed a total of 4695 proteins. Responsive and non-responsive genotypes were compared at 14 and 90 days of callus induction and 221 differentially abundant proteins were obtained. The data analysis revealed several proteins mainly related to energy metabolism, stress response and regulation of cell cycle, further analyzed by qRT-PCR, which seem important for embryogenic development. We suggest some of these proteins as key factors for the success of callus formation in oil palm including antioxidant and cell division proteins as well as proteins involved in the ubiquitination pathway. These proteins may also be potential biomarkers for the acquisition of embryogenic competence. SIGNIFICANCE: Antioxidant and cell division proteins as well as proteins involved in the ubiquitination pathway are key factors for the success of callus formation in oil palm. The proteins identified in this study may be potential biomarkers for embryogenic competence acquisition.

Histopathological Evaluation of the Exposure by Cyanobacteria Cultive Containing [d-Leu¹]Microcystin-LR on Lithobates catesbeianus Tadpoles.

This study evaluated the effects of [d-Leu¹]Microcystin-LR variant by the exposure of Lithobates catesbeianus tadpole to unialgal culture Microcystis aeruginosa NPLJ-4 strain. The Tadpole was placed in aquariums and exposed to Microcystis aeruginosa culture or disrupted cells. For 16 days, 5 individuals were removed every 2 days, and tissue samples of liver, skeletal muscle, and intestinal tract were collected for histopathology and bioaccumulation analyses. After exposure, those surviving tadpoles were placed in clean water for 15 days to evaluate their recovery. A control without algae and toxins was maintained in the same conditions and exhibited normal histology and no tissue damage. In exposed tadpoles, samples were characterized by serious damages that similarly affected the different organs, such as loss of adhesion between cells, nucleus fragmentation, necrosis, and hemorrhage. Samples showed signs of recovery but severe damages were still observed. Neither HPLC-PDA nor mass spectrometry analysis showed any evidence of free Microcystins bioaccumulation.

Disintegrins from snake venoms and their applications in cancer research and therapy.

Integrins regulate diverse functions in cancer pathology and in tumor cell development and contribute to important processes such as cell shape, survival, proliferation, transcription, angiogenesis, migration, and invasion. A number of snake venom proteins have the ability to interact with integrins. Among these are the disintegrins, a family of small, non-enzymatic, and cysteine-rich proteins found in the venom of numerous snake families. The venom proteins may have a potential role in terms of novel therapeutic leads for cancer treatment. Disintegrin can target specific integrins and as such it is conceivable that they could interfere in important processes involved in carcinogenesis, tumor growth, invasion and migration. Herein we present a survey of studies involving the use of snake venom disintegrins for cancer detection and treatment. The aim of this review is to highlight the relationship of integrins with cancer and to present examples as to how certain disintegrins can detect and affect biological processes related to cancer. This in turn will illustrate the great potential of these molecules for cancer research. Furthermore, we also outline several new approaches being created to address problems commonly associated with the clinical application of peptide-based drugs such as instability, immunogenicity, and availability.

Proteome analysis of resting human neutrophils.

Neutrophils constitute the first line of host defense against pathogens. In the present study 2-D gel electrophoresis-mass spectrometry technology was employed to analyze the human resting neutrophils proteome. One hundred and two conserved spots were subjected to peptide mass fingerprinting, yielding 22 identifications. Among the identified proteins, nine are related to the inflammatory process, two polypeptides are assigned to metabolic functions and five are classified as structural.