Morphophysiological Changes Research Articles

Morphophysiological adjustments to shade of jaboticaba tree saplings

We aimed to verify the morphophysiological changes in jaboticaba tree (Plinia peruviana (Poir.) Govaerts) saplings under shade gradient to improve knowledge on the appropriate light environmental conditions for the saplings production and field homogeneous or intercropping cultivation of this species. The saplings were grown under full sun and artificial shade levels (30%, 50%, and 80%). Growth, photosynthetic pigments, gas exchanges, chlorophyll fluorescence, and leaf anatomy characters were evaluated. Our results showed that jaboticaba tree saplings growth was improved under full sun and 30% of shade. Under 50% and 80% shade the saplings demonstrate phenotypic plasticity, such as larger and thinner leaves. Chlorophyll fluorescence, chlorophyll content, and quantum yield of photosystem II were higher under higher shade level, but the CO2 assimilation rate was not different between light conditions. These changes are typically found in shade-tolerant plants and is related to perform photosynthesis more efficiently in highly variable light conditions. Despite that, we recommend that cultivation be carried out under full sun or up to 30% shade to maximize jaboticaba tree saplings growth in nurseries and orchards.

Chemical Stimulation of Heterocyte Differentiation by the Feather Moss Hylocomium splendens: a Potential New Step in Plant-Cyanobacteria Symbioses.

Cyanobacteria associated with mosses play a key role in the nitrogen (N) cycle in unpolluted ecosystems. Mosses have been found to release molecules that induce morphophysiological changes in epiphytic cyanobionts. Nevertheless, the extent of moss influence on these microorganisms remains unknown. To evaluate how mosses or their metabolites influence N2 fixation rates by cyanobacteria, we assessed the nitrogenase activity, heterocyte frequency and biomass of a cyanobacterial strain isolated from the feather moss Hylocomium splendensand a non-symbiotic strain when they were either growing by themselves, together with H. splendens or exposed to H. splendens water, acetone, ethanol, or isopropanol extracts. The same cyanobacterial strains were added to another moss (Taxiphyllum barbieri) and a liverwort (Monosolenium tenerum) to assess if these bryophytes affect N2 fixation differently. Although no significant increases in nitrogenase activity by the cyanobacteria were observed when in contact with H. splendens shoots, both the symbiotic and non-symbiotic cyanobacteria increased nitrogenase activity as well as heterocyte frequency significantly upon exposure to H. splendens ethanol extracts. Contact with T. barbieri shoots, on the other hand, did lead to increases in nitrogenase activity, indicating low host-specificity to cyanobacterial activity. These findings suggest that H. splendens produces heterocyte-differentiating factors (HDFs) that are capable of stimulating cyanobacterial N2 fixation regardless of symbiotic competency. Based on previous knowledge about the chemical ecology and dynamics of moss-cyanobacteria interactions, we speculate that HDF expression by the host takes place in a hypothetical new step occurring after plant colonization and the repression of hormogonia.

Growth of Basella alba under different light environments

Basella alba L. (Malabar spinach) is a non-conventional food plant (PANC) with high nutritional value and economic potential. Light is a critical factor in plant growth, acting directly on the photosynthetic process. The photoselective meshes combine the physical protection of plants with the selective filtering of solar radiation to promote physiological responses. This work evaluates the growth of B. alba under different light environments. The experiment occurred in a greenhouse at the Center for Agrarian, Environmental and Biological Sciences of the Federal University of Recôncavo da Bahia in a completely randomized design with plots comprising one useful plant and five replications. The plants were grown in three light environments: red ChromatiNet mesh, aluminet-thermo reflective mesh (both with 50% irradiance), and under full sun. The red mesh increased the root dry matter mass and stem diameter. The aluminet mesh increased the average number of leaves by about 50% compared to the plants cultivated under full sun. The results show that the cultivation of B. alba in different light environments promotes morphophysiological changes with positive increments in growth.

Rapid ovarian transcript changes during the onset of premature ovarian insufficiency.

Premature ovarian insufficiency (POI) affects 1-3% of women under 40 years of age. The identified causes are highly heterogeneous, and 70% of the cases are idiopathic. The ovarian manifestation varies from a variable population of follicles that fail to develop (follicular POI) to the absence of follicles (afollicular POI) with a transition from one to the other over time. Previously, we have described a mouse model of POI that results from an oocyte-specific deletion of N- and O-glycans; Double Mutant (DM). DM females produce only one litter before undergoing POI due to ovarian dysfunction. In this study, we have characterised the gene expression profile of prepuberal (3 weeks), fertile (6 weeks) and infertile (9 weeks) DM ovaries. Up-regulation of cathepsin K (Ctsk, with unknown ovarian function) seems to trigger transcriptional changes in DM ovaries. Significant transcriptional changes then occur rapidly, associated with morphophysiological changes displayed by DM mice throughout the onset of POI. We identified genetic pathways such as extracellular matrix and immune response as candidates for the onset of POI in DM females. Remarkably, DM mice and POI women share a set of differentially expressed genes, including a functionally and co-expressed network of Mcm (minichromosome maintenance proteins) family members. The transcriptomic profile of the DM mouse model provides novel insight into the aetiology of POI.Lay summaryProblems in ovary function lead to reduced fertility or infertility. One such condition is premature ovarian insufficiency (POI) which affects 1% of women under 40 years of age, and in over 70% of these, the cause of POI is unknown. To investigate POI, we have developed a mouse model. These mice are initially fertile but develop POI by 3 months of age. In this study, we investigated the changes in genes activated in the ovaries during the transition from fertility to POI, and we did this by comparing them to normal mice; gene activation leads to molecule production. A molecule known as cathepsin K seems to trigger changes during the onset of POI, followed by others related to structure and immune response pathways. In addition, some genes were identified that are similar between the POI mice and POI women.

Harder, better, faster, stronger: Frost tolerance of Eucalyptus benthamii under cold acclimation

Eucalypts are the most planted hardwood trees worldwide because of their very rapid growth, exceptional wood quality and adaptability. However, most commercial species and derived hybrids are sensitive to frost, which remains as the largest obstacle to their introduction in warm/temperate climates. As evergreen species, Eucalypts have developed the ability to tolerate frost events based on physiological and molecular responses triggered by previous exposure to cold temperatures, globally named cold acclimation. To characterize the acclimation process in two species with different tolerance to frost, E. grandis (Eg) and E. benthamii (Eb), seedlings were exposed for different times to low temperatures. Frost tolerance was estimated in leaves by an electrolyte leakage assay, and metabolome and morpho-physiological changes studied and correlated to the observed acclimation responses. Eb showed higher basal frost tolerance and an earlier and stronger acclimation response to cold temperatures than in the frost sensitive Eg. Eb was able to modify several morpho-physiological parameters, with a restriction in plant height, leaf area and leaf fresh weight during acclimation. Metabolome characterization allowed us to differentiate species and strengthen our understanding of their acclimation response dynamics. Interestingly, Eb displayed an early phase of sugar accumulation followed by a rise of different metabolites with possible roles as osmolytes and antioxidants, that correlated to frost tolerance and may explain Eb higher capacity to acclimate. This novel approach has helped us to point to the main metabolic processes underlying the cold tolerance acquisition process in two relevant Eucalyptus species.

​​Morpho-physiological and Biochemical Changes under Drought Stress in Strawberry: A Review

Drought stress is one of the most important environmental stress that affects plant growth and development. Strawberry plants are very sensitive to drought stress due to its herbaceous nature and shallow root system. Depending upon the nature, intensity, duration and cultivars, the effect of this stress augments losses in yield and quality of the fruits. This optimization of yield loss and quality is due to the response of the plant to the stress with the changes in morphological, physiological, biochemical and molecular attributes. Drought stress results in the change of leaf anatomy, leaf area, transpiration rate, photosynthesis, stomata closure, relative water content (RWC), shoot length, root length etc. ROS such as H2O2 production occurs as a result of drought causing oxidative damage to the plant cells. Strawberry plant on the other hand have a mechanism to detoxify these ROS with the production of both the enzymatic and non-enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), gluthathione, ascorbic acid, tocopherols, carotenoids etc.

Copper Stress Enhances the Lignification of Axial Organs in Zinnia elegans

Zinnia elegans Jacq. is an ornamental plant, widely used in landscaping. Heavy-metal pollution in urban and rural areas is still increasing, which determines the actuality of studying plants’ reactions to pollutants. Zinnia was not sufficiently studied in this regard, so the aim of our research was to identify morphophysiological changes in this species under excess copper concentration in the soil. For this, we treated a growth substrate with 200 µM CuSO4 solution for 20 days. At the end of the treatment, several morphological, biochemical, and molecular genetic traits were evaluated: the root and the shoot size; the concentration of H2O2 and malondialdehyde (MDA), as indicators of stress; the amount of the phenolic compounds and lignin; and the level of the expression of genes, which encoded their biosynthesis. The Cu amount in the substrate and zinnia organs was quantified using atomic-absorption spectroscopy; hydrogen peroxide, MDA, and phenolic compounds were determined spectrophotometrically, while the amount of lignin was determined according to Klason. Real-time PCR was used for estimation of the gene-transcription level. Lignin in tissues was visualized by fluorescent microscopy. In experimental plants, Cu accumulation was higher in the root than in the stem. This caused an increase in stress markers and a decrease in the root and stem lengths. For the first time for zinnia, it was shown that for several genes—4-coumarate-CoA ligase (4CL), cinnamoyl alcohol dehydrogenase (CAD), and class III peroxidase (PRX)—the level of expression increased under copper treatment. The rise of the transcripts’ amount of these genes was accompanied by a thickening and lignification of the cell walls in the metaxylem vessels. Thus, the adaptation of zinnia to the excess Cu in the growth medium was associated with the metabolic changes in the phenylpropanoid pathway. As a result, the lignification increased in the root, which led to the accumulation of Cu in this organ and limited its translocation through the xylem to the stem, which provided plant growth.

Histological, Morpho-Physiological, and Biochemical Changes during Adventitious Rooting Induced by Exogenous Auxin in Magnolia wufengensis Cuttings

Magnolia wufengensis, a rare ornamental tree species, is now in a huge gap between market demand and actual supply of seedlings. As cutting propagation is one of the most important means to solve the shortage of seedling supply, this study developed an efficient cutting propagation procedure of M. wufengensis, revealed the morphological and histological changes of adventitious root formation, and explored the rhythm correlation between rooting process and physiological and biochemical changes. Cuttings pre-treated with NAA:IBA (2:1) exhibited the best rooting performance. Anatomical analysis demonstrated that adventitious root primordia of M. wufengensis were initiated from cambial and parenchyma cells of xylem, with no relationship to the callus formed on the epidermis. The rooting process of M. wufengenis can be divided into four periods: induction phase (0–8 dap) (dap means days after planting), initiation phase (8–13 dap), expression phase (13–18 dap), and extension phase (18–28 dap). NAA:IBA (2:1) induced the accumulations of 3-indoleacetic-acid and increased the contents of peroxidase and polyphenol-oxidase near the wounding at induction phase. The initiation phase, with the first histological modifications to the formation of meristemoids, correspond to the increase of peroxidase, polyphenol-oxidase, and soluble protein contents. The synergistic reaction of low 3-indoleacetic-acid and high levels of gibberellins and zeatin also stimulates the initiation phase. In the expression and extension phase, high activities of polyphenol-oxidase, IAA-oxidase, and increased contents of soluble protein co-stimulate the emergence and outgrowth of adventitious roots. The present study not only provides optimized protocol by application of auxin combination but also presents insights in the histological, morpho-physiological, and biochemical changes in stem cuttings of M. wufengensis.

Morphophysiological Changes of Quinoa in Response to Soil Application of Nitrogen Under Salinity Stress of Irrigation Water

Morphophysiological Changes of Quinoa in Response to Soil Application of Nitrogen Under Salinity Stress of Irrigation Water

Morphophysiological changes in clearfield oilseed rape as a result of the application of ALS-herbicides and weed competition

Morphophysiological changes in clearfield oilseed rape as a result of the application of ALS-herbicides and weed competition

Morphophysiological responses of Octopus tehuelchus juveniles during the transition period between endogenous and exogenous feeding

In cephalopod hatchlings there is a transitional period considered critical, in which the digestive system undergoes morphophysiological changes associated with the passage from the consumption of vitelline reserves to an independent feeding. During this period, the characterization of the digestive dynamics and growth is key information to define their nutritional requirements under culture. Octopus tehuelchus, which has become increasingly interesting for cultivation, is a species endemic to South America with holobenthic development and large juveniles. In this work, the enzymatic and cytological changes of the digestive gland (DG) along with the variation in body weight and size of O. tehuelchus hatchlings were evaluated when reared at 16 °C under two feeding treatments: fed with the isopod Exosphaeroma sp. and starved. In fed juveniles, the predatory activity began a few hours after hatching; and up to 6 days post hatching (DPH) there was neither somatic growth nor cellular differentiation of the DG, but there was an activation of acid enzymes. From 6 to 10 DPH, there was an increase in the size and weight of juveniles, and the maturation of the DG began with the appearance of heterolysosomes and heterophagosomes. Furthermore, lipases activity reached its maximum level and there was a considerable increase in both alkaline phosphatases and peptidases. From 15 to 25 DPH, the DG became fully mature and the lipase activity reached minimum levels, while the alkaline peptidases continued increasing. At the end of the experiment, at 25 DPH, fed juveniles doubled their weight. In the starved juveniles, neither somatic growth nor cytological differentiations of the DG were registered. Besides, in this treatment, acid phosphatases and lipase activities (i.e. enzymes related to yolk consumption) remained at basal levels or decreased over time, even with yolk platelets still present, suggesting that the consumption of yolk reserves would be delayed, regulating the survival time. In fed juveniles, the ingestion of isopods seems to act as a modulating factor of the digestive activity, triggering an increment in the activity of lipases, acid phosphatases, as well as alkaline peptidases which are related to the digestion of exogenous food. It is concluded that morphological and physiological changes during the digestive maturation are related to the ingestion of Exosphaeroma sp. In this sense, this isopod species would be a suitable food which promotes the rapid growth of O. tehuelchus during their early post-hatching stage under culture.

Morpho-Physiological Responses of Two Multipurpose Species from the Tropical Dry Forest to Contrasting Light Levels: Implications for Their Nursery and Field Management.

Understanding the responses that some plants exhibit to acclimatize and thrive in different light environments can serve as a guideline to optimize their production or establishment. Morpho-physiological changes in Crescentia alata and Enterolobium cyclocarpum were examined in response to varying light levels: 25%, 35%, 55% and 70% of photosynthetic photon flux density (PPFD) of total solar radiation. One-month-old seedlings were subjected to the light treatments; subsequently, the effects on morphology, photosynthetic capacity, nutrient status, non-structural carbohydrate reserves (NSC) and growth were evaluated in three-month-old seedlings. Light levels affected several morpho-physiological parameters. C. alata responded better to higher light levels and E. cyclocarpum to lower levels. Particularly, C. alata with 70% PPFD increased its size in height and diameter, and accumulated more biomass in leaves, stems, and roots; it also exhibited higher net assimilation rates, improved nitrogen and phosphorus status and growth. In contrast, E. cyclocarpum with 25% PPFD increased aboveground biomass, nitrogen levels and NSC in leaves. Both species show morpho-physiological changes that determine their ability to acclimatize to different light conditions. This serves as a basis for designing better management strategies in the nursery or field by defining the light environments conducive to a proper functioning.

Morphophysiological Changes in Genipa americana Seedlings in Response to Root Deformation and Substrate Attributes

Morphophysiological Changes in Genipa americana Seedlings in Response to Root Deformation and Substrate Attributes

Morphophysiological changes in seedlings of two wood species after application of salicylic acid

Morphophysiological changes in seedlings of two wood species after application of salicylic acid

Gall formation in Cereus sp. infected with Diaspis echinocacti Bouché, 1833 (Hemiptera: Diaspididae)

Diaspis echinocacti (Bouché, 1833) (Hemiptera: Diaspididae) is a pest insect that can be responsible for gall formation in cactus (Cereus sp.). The process of gall formation in cactus is not fully understood, and there are few studies available on the interaction of D. echinocacti with the cactus plant. Therefore, the aim of this study was to identify morphophysiological changes in the tissues of Cereus sp. infested with D. echinocacti. We performed histological and ultrastructural analyses and UV/Vis spectrophotometry. Gall formation was only observed in plants infested naturally with D. echinocacti. During histological analysis of the gall samples, we observed the formation of a suber region, interspersed with parenchymal cells and cells with lignified walls. Additionally, there was an increase in xylem conductor bundles and an absence of palisade parenchyma cells. Physiologically, the levels of flavonoids in the gall tissues were reduced compared to those in the control. Our data suggest that D. echinocacti may plays a role in gall formation and triggers cellular and physiological changes in infested Cereus species.

Light management in tree nurseries to produce Pithecellobium dulce seedlings for the reforestation of degraded lands in Southern Mexico's tropical dry forests

The choice of nursery practices is important to the production of high-quality seedlings and to increase the survival rates of reforestation plantations in the dry tropics. However, adequate practices need to be established for native species for which propagation information is scarce. This study suggests that light management in nurseries is a key cultivation practice for future planting success, because of the morpho-physiological changes that plants usually undergo in different light conditions. We examined variations in the morphology, photosynthesis efficiency and growth of Pithecellobium dulce plants produced under four levels of light in nursery conditions (20%, 40%, 60%, and 100% of photosynthetically active radiation [PAR]). We also assessed survival after planting out according to the light conditions under which the plants were grown. Morpho-physiological variables were examined in three-month-old plants. A plantation was established in the field using the nursery-grown plants, and their survival was recorded monthly for 17 months. In the nursery, the light levels had significant effects on morphology, photosynthesis efficiency and growth. The 60% PAR level was favourable to optimum results for most of the variables, whereas the least successful results were found in plants grown at 20% PAR. Seedling survival in the field differed significantly according to the nursery light level, increasing with greater light intensity in the nursery during seedling production. 100% survival was observed in seedlings produced under 100% PAR, whereas the lowest survival rate (53%) was found in seedlings grown under 20% PAR. Light management thus shows potential as a cultivation practice by affecting the quality of P. dulce seedlings, which is improved in the nursery at 60% PAR. However, better survival after planting out is obtained with plants produced under full sun. These results should help to improve nursery management and establishment in the field of P. dulce in projects to restore degraded lands in the dry tropics.

Water Stress Alters Morphophysiological, Grain Quality and Vegetation Indices of Soybean Cultivars.

Rainfall is among the climatic factors that most affect production, as in the Brazilian Cerrado. Non-destructive and automated phenotyping methods are fast and efficient for genotype selection. The objective of this work was to evaluate, under field conditions, the morphophysiological changes, yield, and grain quality of soybean (Glycine max L. Merrill) under water stress in the Brazilian Cerrado. The plots comprised six soybean cultivars and the subplots of four water regimes, corresponding to 31, 44, 64 and 100% of crop evapotranspiration replacement. The experiments were conducted from May to September 2018 and 2019. An irrigation system with a bar of sprinklers with different flow rates was used. Gas exchange, vegetation indices (measured using a hyperspectral sensor embedded in a drone), yield and grain quality were evaluated. Water stress had different effects on gas exchange, vegetation indices, grain yield and chemical composition among the cultivars. Embrapa cultivar BRS 7280 Roundup ready (RR) and Nidera cultivar NA 5909 RG (glyphosate resistant) are yield stable and have a greater tolerance to drought. BRS 7280RR showed a higher tolerance to drought and higher water use efficiency (WUE) than all other tested cultivars. Vegetation indices, such as the NDVI (Normalized Difference Vegetation Index), correlated with the morphophysiological traits, such as plant height, were the most responsive variables to water stress. The NDVI can be used to predict soybean yield as a tool in a selection program under drought.

Antileishmanial Efficacy of the Calpain Inhibitor MDL28170 in Combination with Amphotericin B.

The necessity of drug combinations to treat leishmaniasis came to the surface mainly because of the toxicity of current treatments and the emergence of resistant strains. The calpain inhibitor MDL28170 has previously shown anti-Leishmania activity, therefore its use in association with standard drugs could provide a new alternative for the treatment strategy against leishmaniasis. In this study, we analyzed the potential of the combination of MDL28170 and the antileishmanial drug amphotericin B against Leishmania amazonensis and Leishmania chagasi. The compounds were tested in the combination of the ½ × IC50 value of MDL28170 plus the ¼ × IC50 value of amphotericin B, which led to an increment in the anti-promastigote activity when compared to the single drug treatments. This drug association revealed several and severe morphophysiological changes on parasite cells, such as loss of plasma membrane integrity, reduced size of flagellum, and depolarization of mitochondrial membrane potential besides increased reactive oxygen species production. In addition, the combination of both drugs had a deleterious effect on the Leishmania–macrophage interaction, reflecting in a significant anti-amastigote action, which achieved a reduction of 50% in the association index. These results indicate that the combination treatment proposed here may represent a new alternative for leishmaniasis chemotherapy.

Retraction: Morphophysiological changes in the splenic extracellular matrix of Leishmania infantum-naturally infected dogs is associated with alterations in lymphoid niches and the CD4+ T cell frequency in spleens.

Retraction: Morphophysiological changes in the splenic extracellular matrix of Leishmania infantum-naturally infected dogs is associated with alterations in lymphoid niches and the CD4+ T cell frequency in spleens.

Effects of urbanisation and pollution on the heterophil/lymphocyte ratio in birds from Brazilian Cerrado.

Stressing agents can cause morphophysiological and behavioural changes in several animals, including birds, which are good study models for environmental biomonitoring. The heterophil/lymphocyte ratio (H/L) is an efficient indicator of chronic stresses in birds. In this study, we aimed to compare the H/L ratio of birds between the areas with different levels of urbanisation, anthropogenic noise and carbon monoxide (CO) emission rates. A total of 1288 birds were captured in six Cerrado forest fragments between 2013 and 2019, from which we took blood samples to produce blood smears. In each of these fragments, the noise level was measured with a sound pressure level metre. The CO rates were obtained from the National Institute for Space Research database (INPE-Brazil). There was a higher H/L ratio in individuals captured in urban areas or close to urbanisation with high anthropogenic noise levels and high CO rates, and a lower H/L ratio in individuals from preserved areas, far from urban environments with low noise levels and low CO rates. Six species (Antilophia galeata, Leoptopogon amaurocephalus, Cnemotriccus fuscatus, Lathrotriccus euleri, Turdus leucomelasand Eucometis penicillata) showed a significant difference between the areas and followed the pattern shown by the individuals. The present study showed that birds living in the urban and peri-urban sites have higher values of H/L ratio than birds from rural sites. These results suggest that the H/L ratio can be used as an environmental biomonitoring tool and an efficient parameter to assess chronic stress in birds in degraded environments.