Seasonal Shifts in Tree Water Use and Non-Structural Carbohydrate Storage in a Tropical Dry Forest.

Predictions of increased drought frequency and intensity have the potential to threaten to forest globally. The key to trees response to drought is an understanding of tree water use and carbohydrate storage. Our objective was to evaluate sap velocity and dynamics of non-structural carbohydrates (NSC) in native trees of a dry tropical forest, during rainy and drought periods.

Drought-adapted leaves are produced even when more water is available in dry tropical forest.

Species in dry environments may adjust their anatomical and physiological behaviors by adopting safer or more efficient strategies. Thus, species distributed across a water availability gradient may possess different phenotypes depending on the specific environmental conditions to which they are subjected. Leaf and vascular tissues are plastic and may vary strongly in response to environmental changes affecting an individual's survival and species distribution.

Dehydration response in Stylosanthes scabra: Transcriptional, biochemical, and physiological modulations.

Stylosanthes scabra, popularly known as stylo, is native to the Brazilian Caatinga semiarid region and stands out as a drought-tolerant shrub forage crop. This work provides information about the plant response during the first 48 h of water deficit, followed by a rehydration treatment. Besides root transcriptomics data, 13 physiological or biochemical parameters were scrutinized.

Dynamics of nonstructural carbohydrates in a deciduous woody species from tropical dry forests under recurrent water deficit.

In tropical dry forests, both the dry and the short rainy seasons have become increasingly irregular. This study replicated these conditions to investigate the effects of two water deficit cycles on Cenostigma microphyllum seedlings. Impacts were assessed by measuring growth traits, water relations, gas exchange, and dynamics of nonstructural carbohydrate (NSC) content in the whole plant under greenhouse conditions in potted plants.

Stomatal Responses to Light, CO, and Mesophyll Tissue in and .

The responses of stomatal aperture to light intensity and CO concentration were studied in both (C) and (Crassulacean acid metabolism; CAM), in material sampled from both light and dark periods. Direct comparison was made between intact leaf segments, epidermises grafted onto exposed mesophyll, and isolated epidermal peels, including transplantations between species and between diel periods. We reported the stomatal opening in response to darkness in isolated CAM peels from the light period, but not from the dark.

Reference genes for quantitative real-time PCR normalization of Cenostigma pyramidale roots under salt stress and mycorrhizal association.

Cenostigma pyramidale is a native legume of the Brazilian semiarid region which performs symbiotic association with arbuscular mycorrhizal fungi (AMF), being an excellent model for studying genes associated with tolerance against abiotic and biotic stresses. In RT-qPCR approach, the use of reference genes is mandatory to avoid incorrect interpretation of the relative expression. This study evaluated the stability of ten candidate reference genes (CRGs) from C.

Transcriptome of Cenostigma pyramidale roots, a woody legume, under different salt stress times.

Salinity stress has a significant impact on the gain of plant biomass. Our study provides the first root transcriptome of Cenostigma pyramidale, a tolerant woody legume from a tropical dry forest, under three different salt stress times (30 min, 2 h, and 11 days). The transcriptome was assembled using the RNA sequencing (RNA-Seq) de novo pipeline from GenPipes.

Salt tolerance of begins with immediate regulation of aquaporin activity in the root system.

Unlabelled: The ability to respond quickly to salt stress can determine the tolerance level of a species. Here, we test how rapidly the roots of react to high salinity conditions. In the first 24 h after saline exposure, the plants reduced stomatal conductance, increased CO assimilation, and water use efficiency.

Remobilization of leaf Na content and use of nonstructural carbohydrates vary depending on the time when salt stress begins in woody species.

Basic mechanisms are known to promote salt tolerance in plants: a delay in Na uptake or rapid Na remobilization from leaf tissue. We measured dynamics of the Na/K ratio and components of carbon metabolism during the first 72 h after saline stress (200 mM NaCl) began in Cenostigma pyramidale, a woody species, under controlled conditions. Saline stress at two times: one plant group at the beginning of the morning and the other in the evening.

Different resource-use strategies of invasive and native woody species from a seasonally dry tropical forest under drought stress and recovery.

Exotic plants in semiarid region have developed strategies for efficient use or capture of resources. They have become invasive and outperform native species. To understand which factors could explain the success of invasive woody species in a semiarid region, several physiological traits were analyzed in young plants of two invasive and two native species exposed to different water availability.

Reference genes selection for Calotropis procera under different salt stress conditions.

Calotropis procera is a perennial Asian shrub with significant adaptation to adverse climate conditions and poor soils. Given its increased salt and drought stress tolerance, C. procera stands out as a powerful candidate to provide alternative genetic resources for biotechnological approaches.

Cowpea and abiotic stresses: identification of reference genes for transcriptional profiling by qPCR.

Background: Due to cowpea ability to fix nitrogen in poor soils and relative tolerance to drought and salt stresses, efforts have been directed to identifying genes and pathways that confer stress tolerance in this species. Real-time quantitative PCR (qPCR) has been widely used as the most reliable method to measure gene expression, due to its high accuracy and specificity. In the present study, nine candidate reference genes were rigorously tested for their application in normalization of qPCR data onto roots of four distinct cowpea accessions under two abiotic stresses: root dehydration and salt (NaCl, 100 mM).

Arbuscular mycorrhizal fungi improve photosynthetic energy use efficiency and decrease foliar construction cost under recurrent water deficit in woody evergreen species.

Plants suffer recurrent cycles of water deficit in semiarid regions and have several mechanisms to tolerate low water availability. Thus, arbuscular mycorrhizal fungi (AMF) can alleviate deleterious effects of stress. In this study, Cynophalla flexuosa plants, a woody evergreen species from semiarid, when associated with AMF were exposed to two consecutive cycles of water deficit.

Arbuscular mycorrhizal fungi and foliar phosphorus inorganic supply alleviate salt stress effects in physiological attributes, but only arbuscular mycorrhizal fungi increase biomass in woody species of a semiarid environment.

Salinity may limit plant growth especially in arid and semiarid regions. Arbuscular mycorrhizal fungi (AMF) and the supply of inorganic phosphorus (Pi) could alleviate the negative effects of such stress by improvement in stomatal conductance, photosynthesis and biomass. The aim of this study is to evaluate the ecophysiological performance of Cenostigma pyramidale (Tul.

Photosynthetic limitation and mechanisms of photoprotection under drought and recovery of Calotropis procera, an evergreen C from arid regions.

Calotropis procera is a C plant native from arid environmental zones. It is an evergreen, shrubby, non-woody plant with intense photosynthetic metabolism during the dry season. We measured photosynthetic parameters and leaf biochemical traits, such as gas exchange, photochemical parameters, A/C analysis, organic solutes, and antioxidant enzymes under controlled conditions in potted plants during drought stress, and following recovery conditions to obtain a better insight in the drought stress responses of C.

Seasonal variability in physiological and anatomical traits contributes to invasion success of Prosopis juliflora in tropical dry forest.

We investigated whether there were consistent differences in the physiological and anatomical traits and phenotypic variability of an invasive (Prosopis juliflora (Sw.) DC.) and native species (Anadenanthera colubrina (Vell.

Symbiosis with AMF and leaf P supply increases water deficit tolerance of woody species from seasonal dry tropical forest.

In seasonal dry tropical forests, plants are subjected to severe water deficit, and the arbuscular mycorrhizal fungi (AMF) or inorganic phosphorus supply (P) can mitigate the effects of water deficit. This study aimed to assess the physiological performance of Poincianella pyramidalis subjected to water deficit in combination with arbuscular mycorrhizal fungi (AMF) and leaf inorganic phosphorus (P) supply. The experiment was conducted in a factorial arrangement of 2 water levels (+HO and -HO), 2 AMF levels (+AMF and -AMF) and 2P levels (+P and -P).

Overcoming seed dormancy using gibberellic acid and the performance of young Syagrus coronata plants under severe drought stress and recovery.

Syagrus coronata, a native palm tree of the Brazilian semi-arid region, exhibits low germinability due to seed dormancy. This study aimed to increase the germinability, analyze the morphology of seedlings and evaluate the performance of young plants under a water deficit. We used immersion in water and gibberellic acid (GA3) as pyrene (seed with endocarp) pre-germination treatments, and we analyzed the water relations, gas exchange, chlorophyll fluorescence and carbon balance components of young plants under drought and rehydration conditions.

Stress tolerance and ecophysiological ability of an invader and a native species in a seasonally dry tropical forest.

Ecophysiological traits of Prosopis juliflora (Sw.) DC. and a phylogenetically and ecologically similar native species, Anadenanthera colubrina (Vell.

Different mechanisms drive the performance of native and invasive woody species in response to leaf phosphorus supply during periods of drought stress and recovery.

The effects of drought stress and leaf phosphorus (Pi) supply on photosynthetic metabolism in woody tropical species are not known, and given the recent global environmental change models that forecast lower precipitation rates and periods of prolonged drought in tropical areas, this type of study is increasingly important. The effects of controlled drought stress and Pi supply on potted young plants of two woody species, Anadenanthera colubrina (native) and Prosopis juliflora (invasive), were determined by analyzing leaf photosynthetic metabolism, biochemical properties and water potential. In the maximum stress, both species showed higher leaf water potential (Ψl) in the treatment drought +Pi when compared with the respective control -Pi.

Three cycles of water deficit from seed to young plants of Moringa oleifera woody species improves stress tolerance.

The main objective of this study was to assess whether recurring water stress occurring from seed germination to young plants of Moringa oleifera Lam. are able to mitigate the drought stress effects. Germination, gas exchange and biochemical parameters were analysed after three cycles of water deficit.

Seasonal effects on the relationship between photosynthesis and leaf carbohydrates in orange trees.

To understand the effect of summer and winter on the relationships between leaf carbohydrate and photosynthesis in citrus trees growing in subtropical conditions, 'Valencia' orange trees were subjected to external manipulation of their carbohydrate concentration by exposing them to darkness and evaluating the maximal photosynthetic capacity. In addition, the relationships between carbohydrate and photosynthesis in the citrus leaves were studied under natural conditions. Exposing the leaves to dark conditions decreased the carbohydrate concentration and increased photosynthesis in both seasons, which is in accordance with the current model of carbohydrate regulation.

Daily balance of leaf sugars and amino acids as indicators of common bean (Phaseolus vulgaris L.) metabolic response and drought intensity.

Leaf soluble sugar, starch and free amino acid amounts were evaluated in two bean genotypes, Carioca and Ouro Negro, grown in 10 L pots in a greenhouse. This was realized during a single day for Carioca and during ten days of water deficit for both genotypes, at 06:00 and 18:00 h. During the day, an increase in all parameters occurred up to midday, while in the afternoon, carbohydrate amounts varied in opposition to amino acids amounts.

Approximate Entropy as a measure of complexity in sap flow temporal dynamics of two tropical tree species under water deficit.

Approximate Entropy (ApEn), a model-independent statistics to quantify serial irregularities, was used to evaluate changes in sap flow temporal dynamics of two tropical species of trees subjected to water deficit. Water deficit induced a decrease in sap flow of G. ulmifolia, whereas C.