Alterations in the root phenylpropanoid pathway and root-shoot vessel system as main determinants of the drought tolerance of a soybean genotype.

Climate change increases precipitation variability, particularly in savanna environments. We have used integrative strategies to understand the molecular mechanisms of drought tolerance, which will be crucial for developing improved genotypes. The current study compares the molecular and physiological parameters between the drought-tolerant Embrapa 48 and the sensitive BR16 genotypes. We integrated the root-shoot system's transcriptome, proteome, and metabolome to understand drought tolerance. The results indicated that Embrapa 48 had a greater capacity for water absorption due to alterations in length and volume. Drought tolerance appears to be ABA-independent, and IAA levels in the leaves partially explain the higher root growth. Proteomic profiles revealed up-regulated proteins involved in glutamine biosynthesis and proteolysis, suggesting osmoprotection and explaining the larger root volume. Dysregulated proteins in the roots belong to the phenylpropanoid pathways. Additionally, PR-like proteins involved in the biosynthesis of phenolics may act to prevent oxidative stress and as a substrate for modifying cell walls. Thus, we concluded that alterations in the root-shoot conductive vessel system are critical in promoting drought tolerance. Moreover, photosynthetic parameters from reciprocal grafting experiments indicated that the root system is more essential than the shoots in the drought tolerance mechanism. Finally, we provided a comprehensive overview of the genetic, molecular, and physiological traits involved in drought tolerance mechanisms. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01307-7.

Bovine pancreatic trypsin inhibitor and soybean Kunitz trypsin inhibitor: Differential effects on proteases and larval development of the soybean pest Anticarsia gemmatalis (Lepidoptera: Noctuidae).

Pest management is challenged with resistant herbivores and problems regarding human health and environmental issues. Indeed, the greatest challenge to modern agriculture is to protect crops from pests and still maintain environmental quality. This study aimed to analyze by in silico, in vitro, and in vivo approaches to the feasibility of using the inhibitory protein extracted from mammals - Bovine Pancreatic Trypsin Inhibitor (BPTI) as a potential inhibitor of digestive trypsins from the pest Anticarsia gemmatalis and comparing the results with the host-plant inhibitor - Soybean Kunitz Trypsin Inhibitor (SKTI). BPTI and SKTI interacts with A. gemmatalis trypsin-like enzyme competitively, through hydrogen and hydrophobic bonds. A. gemmatalis larvae exposed to BPTI did not show two common adaptative mechanisms i.e., proteolytic degradation and overproduction of proteases, presenting highly reduced trypsin-like activity. On the other hand, SKTI-fed larvae did not show reduced trypsin-like activity, presenting overproduction of proteases and SKTI digestion. In addition, the larval survival was reduced by BPTI similarly to SKTI, and additionally caused a decrease in pupal weight. The non-plant protease inhibitor BPTI presents intriguing element to compose biopesticide formulations to help decrease the use of conventional refractory pesticides into integrated pest management programs.

Remodeling of the cell wall as a drought-tolerance mechanism of a soybean genotype revealed by global gene expression analysis.

Drought stress is major abiotic stress that affects soybean production. Therefore, it is widely desirable that soybean becomes more tolerant to stress. To provide insights into regulatory mechanisms of the stress response, we compared the global gene expression profiles from leaves of two soybean genotypes that display different responses to water-deficit (BR 16 and Embrapa 48, drought-sensitive and drought-tolerant, respectively). After the RNA-seq analysis, a total of 5335 down-regulated and 3170 up-regulated genes were identified in the BR16. On the other hand, the number of genes differentially expressed was markedly lower in the Embrapa 48, 355 up-regulated and 471 down-regulated genes. However, induction and expression of protein kinases and transcription factors indicated signaling cascades involved in the drought tolerance. Overall, the results suggest that the metabolism of pectin is differently modulated in response to drought stress and may play a role in the soybean defense mechanism against drought. This occurs via an increase of the cell wall plasticity and crosslink, which contributed to a higher hydraulic conductance (K f) and relative water content (RWC%). The drought-tolerance mechanism of the Embrapa 48 genotype involves remodeling of the cell wall and increase of the hydraulic conductance to the maintenance of cell turgor and metabolic processes, resulting in the highest leaf RWC, photosynthetic rate (A), transpiration (E) and carboxylation (A/C i). Thus, we concluded that the cell wall adjustment under drought is important for a more efficient water use which promoted a more active photosynthetic metabolism, maintaining higher plant growth under drought stress. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-021-00043-4.

Mechanism of the drought tolerance of a transgenic soybean overexpressing the molecular chaperone BiP.

Drought is one of major constraints that limits agricultural productivity. Some factors, including climate changes and acreage expansion, indicates towards the need for developing drought tolerant genotypes. In addition to its protective role against endoplasmic reticulum (ER) stress, we have previously shown that the molecular chaperone binding protein (BiP) is involved in the response to osmotic stress and promotes drought tolerance. Here, we analyzed the proteomic and metabolic profiles of BiP-overexpressing transgenic soybean plants and the corresponding untransformed line under drought conditions by 2DE-MS and GC/MS. The transgenic plant showed lower levels of the abscisic acid and jasmonic acid as compared to untransformed plants both in irrigated and non-irrigated conditions. In contrast, the level of salicylic acid was higher in transgenic lines than in untransformed line, which was consistent with the antagonistic responses mediated by these phytohormones. The transgenic plants displayed a higher abundance of photosynthesis-related proteins, which gave credence to the hypothesis that these transgenic plants could survive under drought conditions due to their genetic modification and altered physiology. The proteins involved in pathways related to respiration, glycolysis and oxidative stress were not signifcantly changed in transgenic plants as compared to untransformed genotype, which indicate a lower metabolic perturbation under drought of the engineered genotype. The transgenic plants may have adopted a mechanism of drought tolerance by accumulating osmotically active solutes in the cell. As evidenced by the metabolic profiles, the accumulation of nine primary amino acids by protein degradation maintained the cellular turgor in the transgenic genotype under drought conditions. Thus, this mechanism of protection may cause the physiological activities including photosynthesis to be active under drought conditions.

Ethanol stress responses of Kluyveromyces marxianus CCT 7735 revealed by proteomic and metabolomic analyses.

Kluyveromyces marxianus CCT 7735 offers advantages to ethanol production over Saccharomyces cerevisiae, including thermotolerance and the ability to convert lactose to ethanol. However, its growth is impaired at high ethanol concentrations. Herein we report on the protein and intracellular metabolite profiles of K. marxianus at 1 and 4 h under ethanol exposure. The concentration of some amino acids, trehalose and ergosterol were also measured. We observed that proteins and metabolites from carbon pathways and translation were less abundant, mainly at 4 h of ethanol stress. Nevertheless, the concentration of some amino acids and trehalose increased at 8 and 12 h under ethanol stress, indicating an adaptive response. Moreover, our results show that the abundance of proteins and metabolites related to the oxidative stresses responses increased. The results obtained in this study provide insights into understanding the physiological changes in K. marxianus under ethanol stress, indicating possible targets for ethanol tolerant strains construction.

Proteomic analysis of the venom of the predatory ant Pachycondyla striata (Hymenoptera: Formicidae).

The ants use their venom for predation, defense, and communication. The venom of these insects is rich in peptides and proteins, and compared with other animal venoms, ant venoms remain poorly explored. The objective of this study was to evaluate the protein content of the venom in the Ponerinae ant Pachycondyla striata. Venom samples were collected by manual gland reservoir dissection, and samples were submitted to two-dimensional gel electrophoresis and separation by ion-exchange and reverse-phase high-performance liquid chromatography followed by mass spectrometry using tanden matrix-assisted laser desorption/ionization with time-of-flight (MALDI-TOF/TOF) mass spectrometry and electrospray ionization-quadrupole with time-of-flight (ESI-Q/TOF) mass spectrometry for obtaining amino acid sequence. Spectra obtained were searched against the NCBInr and SwissProt database. Additional analysis was performed using PEAKS Studio 7.0 (Sequencing de novo). The venom of P. striata has a complex mixture of proteins from which 43 were identified. Within the identified proteins are classical venom proteins (phospholipase A, hyaluronidase, and aminopeptidase N), allergenic proteins (different venom allergens), and bioactive peptides (U10-ctenitoxin Pn1a). Venom allergens are among the most expressed proteins, suggesting that P. striata venom has high allergenic potential. This study discusses the possible functions of the proteins identified in the venom of P. striata.

An integrative overview of the molecular and physiological responses of sugarcane under drought conditions.

Drought is the main abiotic stress constraining sugarcane production. However, our limited understanding of the molecular mechanisms involved in the drought stress responses of sugarcane impairs the development of new technologies to increase sugarcane drought tolerance. Here, an integrated approach was performed to reveal the molecular and physiological changes in two closely related sugarcane cultivars, including the most extensively planted cultivar in Brazil (cv. RB867515), in response to moderate (-0.5 MPa) and severe (-1 MPa) drought stress at the transcriptional, translational, and posttranslational levels. The results show common and cultivar exclusive changes in specific genes related to photosynthesis, carbohydrate, amino acid, and phytohormone metabolism. The novel phosphoproteomics and redox proteomic analysis revealed the importance of posttranslational regulation mechanisms during sugarcane drought stress. The shift to soluble sugar, secondary metabolite production, and activation of ROS eliminating processes in response to drought tolerance were mechanisms exclusive to cv. RB867515, helping to explain the better performance and higher production of this cultivar under these stress conditions.

Development of data for the identification and characterization of proteins found in Rhodnius prolixus, Triatoma lecticularia and Panstrongylus herreri.

The data presented here were obtained from the saliva of three triatominae, Rhodnius prolixus, Triatoma lecticularia and Panstrongylus herreri from Montandon et al. study, doi:10.1016/j.ibmb.2016.02.009 [3]. These data were obtained from spectra generated by the mass spectrometry of proteins observed through the analysis of 2-D electrophoretic profiles. The data were analyzed according to the UniProt code, protein name, protein group, isoelectric point and molecular weight, electrophoretic profile, molecular mass referring to UniProt, volume percentage referring to the spot of the electrophoretic profile, number of peptides and percent coverage found by mass spectrometry related to the particular proteins. In addition, there characterizations made the most significant protein per spot, and also characterizations made for biological processes and molecular functions for all identified proteins.

Comparative proteomic analysis of the saliva of the Rhodnius prolixus, Triatoma lecticularia and Panstrongylus herreri triatomines reveals a high interespecific functional biodiversity.

Triatomines are hematophagous arthropods that transmit Trypanosoma cruzi and Trypanosoma rangeli. Feeding behavior and pathogen transmission is known to vary between the different species, and this characteristic is directly or indirectly dependent on the bioactive molecules of the saliva that facilitate the vector-host-parasite interaction. Here, we identify, characterize and compare the sialoproteomic (from the Greek sialo: saliva) repertoire of important species of the main triatomine genera in the Americas (Rhodnius prolixus, Triatoma lecticularia and Panstrongylus herreri) to better explain this interaction through two-dimensional electrophoresis and mass spectrometry. We identified 221 proteins, 69 from R. prolixus, 100 from T. lecticularia and 52 from P. herreri. We identified high abundance molecules with a great potential to modulate host defenses and homeostasis, highlighting Nitrophorin-4 (28.7%), Salivary lipocalin-5 (65.2%) and Putative triabin (20.5%) in R. prolixus, T. lecticularia and P. herreri, respectively. We also observed that only a single hypothetical protein is shared among three species, which was not functionally categorized. This study corroborates previous findings with R. prolixus, increasing the knowledge about this species with relevant proteomic information and comparisons with the other two targets of the study, T. lecticularia and P. herreri, for which no studies are available from a proteomics perspective.

CHEMICAL COMPOSITION, CHARACTERIZATION OF ANTHOCYANINS AND ANTIOXIDANT POTENTIAL OF EUTERPE EDULIS FRUITS: APPLICABILITY ON GENETIC DYSLIPIDEMIA AND HEPATIC STEATOSIS IN MICE.

UNLABELLED: The significance of polyphenol intake for the prevention of chronic diseases is controversial. OBJECTIVE: this study investigated the chemical composition and antioxidant potential of an anthocyanin-rich extract from Euterpe edulis fruits (LPEF) and its effects on liver steatosis in dyslipidemic apoE-/- knockout mice. MATERIALS AND METHODS: mice were divided into G1 (C57BL/6) standard diet; G2 (apoE-/-) standard diet, G3 (apoE-/-) 2% LPEF, G4 (apoE-/-) 6% LPEF, G5 (apoE-/-) 10% LPEF, G6 (apoE-/-) 2% α-tocopherol acetate. After 75 days of treatment, the animals were euthanized. The LPEF contained a high level of monomeric anthocyanins (301.4 mg/100g) and marked antioxidant activity. RESULTS: Catalase activity was reduced in G3, G4, G5 and G6 compared to G2. Superoxide dismutase was reduced only in G4. The animals in G4, G5, and G6 showed low HDL and triglycerides levels compared to G2. The proportion of lipid droplets in liver tissue was reduced in G4 and G5 compared to G2, G3, and G6. CONCLUSION: The results indicated that E. edulis pulp is rich in anthocyanins and the LPEF dietary consumption can reduce the severity of liver steatosis in apoE-/- mice, an effect that is potentially mediated by the antioxidant activity of this extract and modulation of triglyceride serum levels.

El papel de los polifenoles en la prevención de enfermedades crónicas es controvertido. Objetivo: este estudio investigó la composición química y el potencial antioxidante de un extracto del fruto de Euterpe edulis rico en antocianinas (LPEF) y sus efectos en la esteatosis hepática en ratones apoE-/- knockout con dislipidemia. Material y métodos: los ratones fueron divididos en los siguientes grupos; G1 (C57BL/6) con una dieta estándar; G2 (apoE-/-) con dieta estándar; G3 G3 (apoE-/-) con 2% de LPEF; G4 (apoE-/-) con 6% de LPEF; G5 (apoE-/-) con 10% de LPEF y G6 (apoE-/-) con 2% acetato α-tocoferol (α-tocopherol acetate). Después de 75 días de tratamiento, los animales fueron eutanizados. El LPEF contenía un alto nivel de antocianinas monoméricas (301,4 mg/100 g) con notable actividad antioxidante. Resultados: la actividad catalasa fue reducida en los grupos G3, G4, G5 y G6 comparada con G2. La superoxidasa dismutasa solo se redujo en el grupo G4. Los animales de G4, G5 y G6 mostraron bajos niveles de HDL triglicéridos, comparados con G2. La proporción de lípidos en el tejido hepático fue reducida en G4 y G5, comparado con G2, G3 y G6. Conclusión: los resultados indicaron que la pulpa de E. edulis es rica en antocianinas, y que el consumo de LPEF en la dieta puede reducir la severidad de la esteatosis hepática en ratones apoE-/-, un efecto que es potencialmente mediado por la actividad antioxidante de este extracto y la modulación en los niveles séricos de triglicéridos.