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.

Novel proteinase inhibitor from the hemolymph of soybean pest Anticarsia gemmatalis (lepidóptera: Noctuidae): Structural modeling and enzymatic kinetic

New approaches are needed to reduce risks to the environment and natural enemies and to avoid or delay the onset of insecticide resistance. The use of insecticides based on proteinase inhibitors of hemolymph is an alternative for the control of Lepidoptera pests primarily by having low toxicity and short persistence in the environment. Thus, in this study, we describe the purification process and identification of protease inhibitors from hemolymph Anticarsia gemmatalis and their activities against trypsin enzymes. Furthermore, the three-dimensional (3D) structure of the inhibitor and binding mode to trypsin enzymes was determined, and the stability of the inhibitory activity in several pHs and temperature values was evaluated. The inhibitor was characterized as a serpin family inhibitor and named A. gemmatalis hemolymph serpin inhibitor (AHSI), with an approximate mass of 38 ± 2 kDa, highly stable to temperature and pH variations, and with inhibitory capacity on bovine trypsin and gut trypsin of A. gemmatalis demonstrated by calculated Ki values and affinity energy through molecular docking, being a reversible competitive inhibitor that binds to the active site of trypsin-like enzymes. We conclude that the AHSI inhibitor identified from the hemolymph of the soybean pest A. gemmatalis preserves the original structure of the serpin family with a good overall stereochemical quality confirmed from molecular modeling. The docking analysis showed that the reactive site of the inhibitor is in contact with the catalytic cavity of the trypsin with high-affinity energy.

Uterine infusion of conceptus fragments changes the protein profile from cyclic mares

This experiment aimed to compare at day seven after ovulation, the protein profile of uterine fluid in cyclic mares with mares infused two days before with Day 13 conceptus fragments. Experimental animals were ten healthy cyclic mares, examined daily to detect ovulation (Day 0) as soon as estrus was confirmed. On day seven, after ovulation, uterine fluid was collected, constituting the Cyclic group (n = 10). The same mares were examined in the second cycle until ovulation was detected. On day five, after ovulation, fragments from a previously collected concepti were infused into each mare's uterus. Two days after infusion, uterine fluid was collected, constituting the Fragment group (n = 10). Two-dimensional electrophoresis technique processed uterine fluid samples. A total of 373 spots were detected. MALDI-TOF/TOF and NanoUHPLC-QTOF mass spectrometry identified twenty spots with differences in abundance between the Cyclic and Fragment group. Thirteen proteins were identified, with different abundance between groups. Identified proteins may be related to embryo-maternal communication, which involves adhesion, nutrition, endothelial cell proliferation, transport, and immunological tolerance. In conclusion, conceptus fragments signalized changes in the protein profile of uterine fluid seven days after ovulation in comparison to the observed at Day 7 in the same cyclic mares.

Physiological approach to decipher the drought tolerance of a soybean genotype from Brazilian savana

Drought is one of the major constraints for soybean production in Brazil. In this study we investigated the physiological traits of two soybean parental genotypes under progressive soil drying and rewetting. The plants were evaluated under full irrigation (control) conditions and under water deficit imposed by suspending irrigation until the plants reached predawn leaf water potentials (Ψam) of -1.0 MPa (moderate) and -1.5 MPa (severe). Physiological analyses showed that these genotypes exhibit different responses to water deficit. The Embrapa 48 genotype reached moderate and severe water potential two days after the BR16 genotype and was able to maintain higher levels of A, ETR and ΦPSII even under deficit conditions. This result was not related to changes in gs, 13C isotopic composition and presence of a more efficient antioxidant system. In addition, Fv/Fm values did not decrease in Embrapa 48 genotype in relation to irrigated condition showing that stress was not causing photochemical inhibition of photosynthesis. The greater reduction in the relative growth of the shoots, with concomitant greater growth of the root system under drought, indicates that the tolerant genotype is able to preferentially allocated carbon to the roots, presenting less damage to photosynthesis. Therefore, the physiological responses revealed that the tolerant genotype postponed leaf dehydration by a mechanism involving a more efficient use and translocation of water from root to shoot to maintain cell homeostasis and photosynthetic metabolism under stress.

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.

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

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.