Xerophytic Plants Research Articles

First Record of Endophytic fungi Thielavia basicola Isolated from Xerophyte Plants Suaeda aegyptiaca in Basra, Iraq

Abstract This study was conducted with the aim of isolating endophytic fungi from the xerophyte plant Suaeda aegyptiaca. In this study, Thielavia basicola was isolated from the stem of the plant S. aegyptiaca spread in Basrah city, fungus was identified basis on its morphological features and molecular based on amplification of the ITS gene region and the nucleotide sequence of the fungus was deposited in the Genebank under the accession number MT277121.1. The metabolites of the fungal filtrate T. basicola were identified using by GC-MS technology and the results showed that this fungus produces 40 compounds as extracellular secondary metabolites, the most important of which are 9-Octadecenamide, (Z)- and Tributylacetylcitrate and N-Hexadecanoic acid. This is the first study in which T. basicola is isolated from S. aegyptiaca from desert in Iraq.

First record of three Endophytic fungi isolated from xerophyte plants in Basra, Iraq

This study was conducted with the aim of isolating endophytic fungi from some xerophyte plants. In this study, three fungi were isolated from the internal tissues of some plants spread in the city of Basrah, Xenomyrothecium tongaense from the stem of Suaeda aegyptiace, Chaetomium megalocarpum from the roots, stem and leaves of Caroxylon jordanicola and Cephaliophora irregularis from the leaves of Cressa cretica. Fungus was identified based on its morphological features and molecular based on the amplification of the ITS gene region and the nucleolide sequence of the fungi was deposited in the genebank under accession number NR-154511.1, KT371335.1 and OM245865.1 for fungi Xenomyrothecium tongaense, Chaetomium megalocarpum and Cephaliophora irregularis, respectively. This is the first study in which these fungi are isolated from desert in Iraq.

Morphological, Metabolomic and Genomic Evidences on Drought Stress Protective Functioning of the Endophyte Bacillus safensis Ni7.

The metabolomic and genomic characterization of an endophytic Bacillus safensis Ni7 was carried out in this study. This strain has previously been isolated from the xerophytic plant Nerium indicum L. and reported to enhance the drought tolerance in Capsicum annuum L. seedlings. The effects of drought stress on the morphology, biofilm production, and metabolite production of B. safensis Ni7 are analyzed in the current study. From the results obtained, the organism was found to have multiple strategies such as aggregation and clumping, robust biofilm production, and increased production of surfactin homologues under the drought induced condition when compared to non-stressed condition. Further the whole genome sequencing (WGS) based analysis has demonstrated B. safensis Ni7 to have a genome size of 3,671,999bp, N50 value of 3,527,239, and a mean G+C content of 41.58%. Interestingly the organism was observed to have the presence of various stress-responsive genes (13, 20U, 16U,160, 39, 17M, 18, 26, and ctc) and genes responsible for surfactin production (srfAA, srfAB, srfAC, and srfAD), biofilm production (epsD, epsE, epsF, epsG, epsH, epsI, epsK, epsL, epsM, epsN, and pel), chemotaxis (cheB_1, cheB_2, cheB_3, cheW_1, cheW_2 cheR, cheD, cheC, cheA, cheY, cheV, and cheB_4), flagella synthesis (flgG_1, flgG_2, flgG_3, flgC, and flgB) as supportive to the drought tolerance. Besides these, the genes responsible for plant growth promotion (PGP), including the genes for nitrogen (nasA, nasB, nasC, nasD, and nasE) and sulfur assimilation (cysL_1&L_2, cysI) and genes for phosphate solubilization (phoA, phoP_1& phoP_2, and phoR) could also be predicted. Along with the same, the genes for catalase, superoxide dismutase, protein homeostasis, cellular fitness, osmoprotectants production, and protein folding could also be predicted from its WGS data. Further pan-genome analysis with plant associated B. safensis strains available in the public databases revealed B. safensis Ni7 to have the presence of a total of 5391 gene clusters. Among these, 3207 genes were identified as core genes, 954 as shell genes and 1230 as cloud genes. This variation in gene content could be taken as an indication of evolution of strains of Bacillus safensis as per specific conditions and hence in the case of B. safensis Ni7 its role in habitat adaptation of plant is well expected. This diversity in endophytic bacterial genes may attribute its role to support the plant system to cope up with stress conditions. Overall, the study provides genomic evidence on Bacillus safensis Ni7 as a stress alleviating microbial partner in plants.

Reconstruction of zonal vegetation of East Asia in the early Eocene

For the fi rst time, unifi ed types of zonal vegetation are established for the early Eocene in east of Asia and their changes in space are traced. The reconstruction is based on the analysis of 48 palynofl oras from the early Eocene localities situated from 75 to 19° N using Integrated Plant Record (IPR) vegetation analysis. In the results, quantitative parameters of the relative proportions of vegetation components are obtained. According to our data, along the latitudinal gradient from north to south, there is an increase in evergreen plants and herbs, but a decrease in conifers and deciduous plants, and no changes in the proportions of xerophytic plants. Mixed mesophytic forest is a widespread and dominant type of zonal vegetation. In general, the main changes in plant biomes show a very shallow and weakly pronounced diff erentiation into two plant zones: mixed mesophytic forest, north of ~50° paleolatitude, and warmer types of zonal vegetation (broadleaved evergreen forest and an ecotone between mixed mesophytic and broadleaved evergreen forests), in addition to mixed mesophytic forest, south of ~50° paleolatitude. The resulting spatial patterns of vegetation are consistent with climatic inferences.

Greening a lost world: Paleoartistic investigations of the early Pleistocene vegetation landscape in the first Europeans' homeland

The scarcity of pictorial reconstructions focusing on Quaternary flora and vegetation prompts a reevaluation of traditional zoocentrism in future paleoartistic research. Here we present paleoartistic renderings depicting vegetation landscapes around the Orce Archaeological Zone (OAZ), encompassing sites dating from 1.6 to 1.2 million years ago during the Early Pleistocene of the Guadix-Baza Basin in southern Spain. Four pieces are based on fossil pollen data from Venta Micena 1 (VM1), Barranco León (BL), and Fuente Nueva 3 (FN3). The artwork considers altitudinal belt distribution, taxonomic and structural diversity, extinct taxa in the Iberian Peninsula post-Early Pleistocene, and those previously extinct at higher latitudes in Europe. This essay visually represents the coexistence of mesophytic, thermophytic, and xerophytic plant communities within a glacial refugium of woody species. Lastly, employing a non-conventional iconographic approach, we portray a female Homo individual in the forest refugium to draw up on possible adaptive traits of these early Europeans.

Ajania fastigiata in Zhetysu Alatau: Distribution, morphological characterization, phytochemical profiles, and optimization of extraction of bioactive constituents

Despite the wide medicinal use of Ajania fastigiata (C. Winkl.) Poljakov. in folk medicine, most Ajania species from Central Asia have not been explored comprehensively. Resource data revealed that A. fastigiata growing in the Zhetysu Alatau of Kazakhstan in three gorges among the Terekty river valley, Maliy Baskan, Sarkan, and the Karasyryk gorge at altitudes of 1183–1510 m. Anatomical and morphological studies were carried out on the vegetative organs of plants and results can be noted that A. fastigiata is typical for xerophytic plants growing in conditions of lack of moisture. Phytochemical investigation of the main bioactive constituents, together with the plant quality standardization were determined by the methods of State Pharmacopeia. Eleven macro-, and microelements of the A. fastigiata were identified with analysis of multi-element atomic emission spectral. Moreover, A. fastigiata demonstrated notable effectiveness against enzymes related diabetes and bacterial infections (α-glucosidase, PTP1B, BNA) and encouraging antioxidant properties. It is concluded that A. fastigiata is widely distributed and has potential ethnobotanical use with strong phytochemical composition which pharmacological active composition extraction method was determined by optimization model. The ideal parameters were identified as follows: a temperature of 50 °C, a time of 120 minutes, and a sonication power of 30 kHz for both dichloromethane (DCM) and ethyl acetate (EtOAc) extracts of A. fastigiata. Under these optimized conditions, the DPPH-RSA values for the DCM and EtOAc extracts were determined to be 41.84% and 83.08%, respectively, and matched the anticipated results.

BIOACTIVE COMPOUNDS AND PHARMACOGNOSTIC POTENTIAL OF Tetragonia tetragonioides

In the recent years, due to the increasing resistance of pathogens to synthetic antimicrobial drugs, the use of highly active compounds from plants, which have proven their effectiveness in traditional medicine practices, is increased. Extracts of medicinal plants often contain a unique species ‒ specific combination of active ingredients that have a synergistic therapeutic effect. Therefore, the analysis of the biochemical composition of cultivated plants and the range of their potential biotechnological application is an urgent task. Aim. To summarize the information on the potential of the xerophytic plant Tetragonia tetragonioides as a source of functional food ingredients and biologically active substances that increase nonspecific organism resistance and contribute to the prevention and treatment of various diseases. Results. T. tetragonioides is a salt-tolerant and heat-resistant plant containing valuable nutrients and biologically active substances, a significant amount of vitamins, minerals, and dietary fibers. The high level of antioxidant compounds, especially flavonoids and carotenoids, helps to reduce the risk of degenerative pathologies developing associated with excessive oxidative stress. The unique complex of biologically active substances in T. tetragonioides, which includes 6-methoxyflavonols, predominantly derivatives of 6-methoxykaempferol, as well as megastigmanes and their glucosides, lignanamide, provides significant antioxidant, anti-inflammatory, antitumor, and antimicrobial activity and may be beneficial for the prevention of chronic diseases and age-related health problems. The effectiveness of T. tetragonioides has been demonstrated in animal models in the treatment of metabolic disorders such as obesity, hyperlipidemia, and hyperuricemia. Conclusions. T. tetragonioides, containing a specific complex of biologically active compounds, primarily 6-methoxyflavonols, may be a promising raw material for obtaining effective medications for the treatment and prevention of various chronic diseases and metabolic disorders.

Antifungal activity of prospective strains of endophytic bacteria

In this study, a collection of promising endophytic bacterial strains F. solani, R. solani, Aspergilus isolated from some halophyte and xerophyte plants. sp., Alternaria sp. the results of research on determining antifungal activity in vitro against phytopathogenic fungi such as The obtained information can serve to increase the variety of tools used in the fight against fungal diseases of agricultural crops.

Leaf traits and fog harvest potential in xerophytic plants

Leaf traits and fog harvest potential in xerophytic plants

Drought-Alleviating Effects of Endophytic Bacteria Isolated from Xerophytic Plants on Capsicum annuum L. Seedlings.

In the current study, 51 endophytic bacteria were isolated from 5 different xerophytic plants. Their drought tolerance properties were screened in vitro, and from these, four endophytes with tolerance up to - 1.5MPa water potential were further selected and identified as Acinetobacter sp. Eo3, Pseudomonas sp. Ni5, Bacillus safensis Ni7, and Stenotrophomonas sp. C3. Due to biosafety concern, Acinetobacter sp. Eo3 and Pseudomonas sp. Ni5 were excluded from further investigation, while B. safensis Ni7 and Stenotrophomonas sp. C3 were subjected to detailed study. The drought tolerance properties of these endophytes were evaluated in vivo using Capsicum annuum L. by analysing the growth parameters (leaf number, root number, shoot length, and plant fresh weight) as well as physiological and biochemical parameters (stomatal index, relative water content, chlorophyll content, and carbohydrate accumulation) of bacteria-treated and control seedlings. Here, treatment with B. safensis Ni7 and Stenotrophomonas sp. C3 was found to result in statistically significant enhancement (P ≤ 0.001) of the measured parameters of plants when compared with the control groups. In the case of fresh weight itself, Ni7 and C3 treatment was found to result in values of 157.76and 142.8mg, respectively, and was statistically significant enhancement as the same for nutrient broth and distilled water control were 73.3mg and 70.5mg only. Additionally, the endophyte-treated seedlings displayed significant improvement in other growth parameters even under induced drought stress. These findings highlight the potential of xerophytic-derived bacterial endophytes to have significant role in mitigating thedrought stress effects in plants with the promises for field application.

Impact of the climatic changes in the Pliocene-Pleistocene transition on Irano-Turanian species. The radiation of genus Jurinea (Compositae)

The Irano-Turanian region is one of the world’s richest floristic regions and the centre of diversity for numerous xerophytic plant lineages. However, we still have limited knowledge on the timing of evolution and biogeographic history of its flora, and potential drivers of diversification remain underexplored. To fill this knowledge gap, we focus on the Eurasian genus Jurinea (ca. 200 species), one of the largest plant radiations that diversified in the region. We applied a macroevolutionary integrative approach to explicitly test diversification hypotheses and investigate the relative roles of geography vs. ecology and niche conservatism vs. niche lability in speciation processes. To do so, we gathered a sample comprising 77% of total genus richness and obtained data about (1) its phylogenetic history, recovering 502 nuclear loci sequences; (2) growth forms; (3) ecological niche, compiling data of 21 variables for more than 2500 occurrences; and (4) paleoclimatic conditions, to estimate climatic stability. Our results revealed that climate was a key factor in the evolutionary dynamics of Jurinea. The main diversification and biogeographic events that occurred during past climate changes, which led to colder and drier conditions, are the following: (1) the origin of the genus (10.7 Ma); (2) long-distance dispersals from the Iranian Plateau to adjacent regions (∼7–4 Ma); and (3) the diversification shift during Pliocene-Pleistocene Transition (ca. 3 Ma), when net diversification rate almost doubled. Our results supported the pre-adaptation hypothesis, i.e., the evolutionary success of Jurinea was linked to the retention of the ancestral niche adapted to aridity. Interestingly, the paleoclimatic analyses revealed that in the Iranian Plateau long-term climatic stability favoured old-lineage persistence, resulting in current high species richness of semi-arid and cold adapted clades; whereas moderate climate oscillations stimulated allopatric diversification in the lineages distributed in the Circumboreal region. In contrast, growth form lability and high niche disparity among closely related species in the Central Asian clade suggest adaptive radiation to mountain habitats. In sum, the radiation of Jurinea is the result of both adaptive and non-adaptive processes influenced by climatic, orogenic and ecological factors.

Plant growth-promoting properties of endophytic bacteria isolated from some xerophytic plants distributed in arid regions (Uzbekistan)

Recent advancements in the development of endophytic microorganisms-based stimulants have shown promising potential in various fields. Research on the identification of these endophytic microorganisms has been well reported, however, there are limited studies of these endophytes isolated from plants in arid regions. Thus, isolation and identification of promising microbial endophytes from xerophytic plants is essential in technology development for sustainable agriculture in arid regions. This study aims to identify the endophytic bacteria isolated from Kochia prostrata (L.) Schrad. and Ceratoides eversmanniana (Stschegl. ex I.G.Borshch.) Botsch. & Ikonn. in vertical zones of arid regions of Uzbekistan, and examine their potential plant growth-promoting properties. Using Luria-Bertani (LB) medium, 70 distinct bacterial colony were isolated from the different segments of K. prostrata and C. eversmanniana. These isotypes were screened using NaCl-supplemented LB medium in which nine promising bacterial isolates showed tolerance to 15% NaCl. The nine promising halophytes were subjected to molecular identification using specific primers. The isolates from K. prostrata are identified as Bacillus amyloliquefaciens, Bacillus pumilus, Priestia aryabhattai, Pseudomonas putida, and Priestia endophytica. On the other hand, Priestia megaterium, Pseudomonas putida, Bacillus subtilis and Brevibacillus parabrevis were isolated from C. eversmanniana. The identified isolates also showed significant plant growth-promoting properties (N2-fixation, IAA production, phosphates solubilization, ACC deaminase production, siderophores production) and shows ability to inhibit pathogenic fungal growth. Based on the result, the identified bacterial endophytes can be processed as growth-stimulants and biological control of fungal pathogens in crops in arid regions.

Review On the Desert Adaptations In Camel At Region Of Thar Desert In Churu District, Rajasthan, India

The study conducted in the Thar Region of Churu district including villages also at Rajasthan state in India. It includes a study on Desert adaptations which founds in Camel in Thar Desert. Thar desert one of the tropical deserts. In region of Thar Desert xerophytic plants and xerocole animals are found. All herbivorous animals depend on vegetations found here. Camel belongs to mammalia class of chordate phylum. The Camel is able to live in Thar Desert with its adaptations for this type of environment. Adaptations makes comfortable to an animal or a plant to well develop in particular area where they are founds. Find out the amazing adaptive features of camel in this study.

Chromosome-level genome assembly of an endangered plant Prunus mongolica using PacBio and Hi-C technologies.

Prunus mongolica is an ecologically and economically important xerophytic tree native to Northwest China. Here, we report a high-quality, chromosome-level P. mongolica genome assembly integrating PacBio high-fidelity sequencing and Hi-C technology. The assembled genome was 233.17 Mb in size, with 98.89% assigned to eight pseudochromosomes. The genome had contig and scaffold N50s of 24.33 Mb and 26.54 Mb, respectively, a BUSCO completeness score of 98.76%, and CEGMA indicated that 98.47% of the assembled genome was reliably annotated. The genome contained a total of 88.54 Mb (37.97%) of repetitive sequences and 23,798 protein-coding genes. We found that P. mongolica experienced two whole-genome duplications, with the most recent event occurring ~3.57 million years ago. Phylogenetic and chromosome syntenic analyses revealed that P. mongolica was closely related to P. persica and P. dulcis. Furthermore, we identified a number of candidate genes involved in drought tolerance and fatty acid biosynthesis. These candidate genes are likely to prove useful in studies of drought tolerance and fatty acid biosynthesis in P. mongolica, and will provide important genetic resources for molecular breeding and improvement experiments in Prunus species. This high-quality reference genome will also accelerate the study of the adaptation of xerophytic plants to drought.

Reconstruction of the Environmental Conditions of the Ob and Irtysh Regions on the Basis of the Rodent Fossil Fauna

The paper compares different approaches to the reconstruction of environmental conditions from rodent fossil complexes, namely, the bioclimatic method and the method of reconstructing soil and plant conditions considering voles. For the reconstruction, data from ten localities in Western Siberia dated to the second half of the Middle Pleistocene were analyzed. The bioclimatic method allowed us to reconstruct the arid climatic zone in the south of Western Siberia (the Pre-Altai Plain and the Middle Irtysh) and the moderately cold and arctic climate for the localities situated northwards. The method of reconstruction of soil and vegetation conditions showed the predominance of xerophytic plant communities for the southern localities and mesophytic, mesohygrophytic, and hygrophytic for the northern ones. As additional indicators of environmental conditions, specialized species were proposed: subterranean animals (Siberian zokor and northern mole voles) and briophages (West Siberian lemming).

Prosopis juliflora (Sw.) DC phytochemicals induce apoptosis and inhibit cell proliferation signaling pathways, EMT, migration, invasion, angiogenesis and stem cell markers in melanoma cell lines

Ethnopharmacological relevanceProsopis juliflora (Sw.), DC is a xerophytic plant species that extensively grow in Asia, Africa, Australia, and Brazil. From ancient time P. juliflora is being utilized in various folk remedies for example in wound healing, fever, inflammation, measles, excrescences, diarrhea and dysentery. Traditionally, gum, paste, and smoke obtained from the leaves and pods are applied for anticancer, antidiabetic, anti-inflammatory, and antimicrobial purposes. Aim of the studyOur previous studies have demonstrated the promising potential of Prosopis Juliflora leaves methanol extract (PJLME) against breast cancer, and suggested its possible integration as a complementary medicine for the effective management of breast cancer. However, evidence against how PJLME mechanistically target the cancer proliferative pathways and other targets is poorly understood. The basic aim of the present study was to understand the anti-melanoma potential of PJLME against B16f10 cells with possible mechanisms of action. Materials and methodsMTT assay was used to determine cell viability. Wound and transwell migration assay was performed to check migration potential of cells after PJLME treatment, while clonogenic assay was carried out to understand its colony inhibition actvity. Flow cytometry was used to perform annexin V/PI assay (apoptosis assay), ROS assay, cell cycle analysis. In-vitro angiogenesis assay was performed to check formation of capillary like vascular structure after PJLME treatment. Apoptotic genes, signaling pathways markers, EMT markers and stem cell markers were determined by western blotting. In-vivo BALB/C mice xenograft model study was performed to check the effect of PJLME on in-vivo melanoma tumor growth. ResultsThe experimental outcome of the present study has clearly demonstrated the inhibition of growth, migration, invasion, colony formation and apoptosis inducing potential of PJLME against mouse melanoma cancer cells. Treatment of B16F10 melanoma cells with PJLME resulted in arrest of cell cycle at G0/G1 phase. Annexin V-FITC/PI assay confirmed the apoptosis inducing potential of PJLME in B16F10 and A375 melanoma cells. Furthermore, Western blot experiments confirmed that the treatment of PJLME downregulates the expression of anti-apoptotic gene like Bcl2 and increase the expression profile of pro-apoptotic genes like Bax, Bad, and Bak in B16F10 melanoma cells. HUVEC (Human umbilical vein endothelial cells) tube formation assay clearly demonstrated the anti-angiogenic potential of PJLME. The study also revealed that PJLME has potential to inhibit the Akt and Erk signaling pathways which are participating in cancer cell proliferation, migration, invasion etc. The outcome of qRT-PCR and immunoblotting analysis clearly unveiled that PJLME treatment leads to downregulation of epithelial-mesenchymal transition (EMT) as well as stem cell markers. Finally, the in-vivo animal xenograft model study also revealed the anti-melanoma potential of PJLME by significantly inhibiting the B16F10 melanoma tumor growth in BALB/c mice model. The LC-ESI-MS/MS analysis of PJLME showed the presence of variety of bioactive molecules associated with anticancer effects. ConclusionThe outcome of the present investigation clearly demonstrated the anti-melanoma potential of PJLME against B16f10 melanoma cells. PJLME can be explored as an adjuvant or complementary therapy against melanoma cancer, however further studies are required to understand the clinical efficacy of PJLME. Nevertheless, it can be further explored as a promising resource for identification of novel anticancer candidate drug.

Differences between stem and branch xylem water isotope composition in four tropical tree species

AbstractStable isotope studies (δ2H and δ18O) of water within plants are providing new information on water sources, competitive interactions and water use patterns under natural conditions. This is based on the assumption that there is no fractionation at the time of water uptake or during its transport within trees. However, previous studies have found fractionation does occur in water taken up through the roots in halophytic and xerophytic plants. It is unclear how widespread such fractionation is in other species. In this study, we tested this fractionation by comparing stem and branch xylem water isotopes over the period of one day (from 8 am to 5 pm) in four wet tropical rainforest tree species (Dendrocnide photinophylla,Aphananthe philippinensis,Daphnandra repandulaandMallotus polyadenos). We found branch water isotope ratios (δ2H and δ18O) were enriched compared with stem xylem water isotopes.D. photinophyllahad a significantly different branch δ18O ratio thanA. philippinensis,D. repandulaandM. polyadenos. In contrast, there were no significant differences in stem xylem δ18O among the four observed tree species. We found clear differences in the stable isotope ratios of δ18O for stem and branch xylem water forD. photinophyllaandD. repandulaof upto −0.85% and 0.50%, respectively. Remarkable δ2H differences were also found between stem and branch xylem water isotope ratios forA. philippinensis,D. repandulaandM. polyadenos, being upto −12.14%, −16.17% and −9.65%, respectively. A dual isotope (δ2H–δ18O) plot showed branch water values were more enriched than stem xylem water values forD. photinophyllaandD. repandula, indicating a clear difference between stem and branch xylem water. This study suggests that δ2H and δ18O fractionation could be a species‐specific phenomenon in tropical trees, which has important implications for plant water source identification and evapotranspiration partitioning.

Relieving your stress: PGPB associated with Andean xerophytic plants are most abundant and active on the most extreme slopes.

Plants interact with plant growth-promoting bacteria (PGPB), especially under stress condition in natural and agricultural systems. Although a potentially beneficial microbiome has been found associated to plants from alpine systems, this plant- PGPB interaction has been scarcely studied. Nevados de Chillán Complex hold one of the southernmost xerophytic formations in Chile. Plant species living there have to cope with drought and extreme temperatures during the growing season period, microclimatic conditions that become harsher on equatorial than polar slopes, and where the interaction with PGPB could be key for plant survival. Our goal was to study the abundance and activity of different PGPB associated to two abundant plant species of Andean xerophytic formations on contrasting slopes. Twenty individuals of Berberis empetrifolia and Azorella prolifera shrubs were selected growing on a north and south slope nearby Las Fumarolas, at 2,050 m elevation. On each slope, microclimate based on temperature and moisture conditions were monitored throughout the growing period (oct. - apr.). Chemical properties of the soil under plant species canopies were also characterized. Bacterial abundance was measured as Log CFU g-1 from soil samples collected from each individual and slope. Then, the most abundant bacterial colonies were selected, and different hormonal (indoleacetic acid) and enzymatic (nitrogenase, phosphatase, ACC-deaminase) mechanisms that promote plant growth were assessed and measured. Extreme temperatures were observed in the north facing slope, recording the hottest days (41 vs. 36°C) and coldest nights (-9.9 vs. 6.6°C). Moreover, air and soil moisture were lower on north than on south slope, especially late in the growing season. We found that bacterial abundance was higher in soils on north than on south slope but only under B. empetrifolia canopy. Moreover, the activity of plant growth-promoting mechanisms varied between slopes, being on average higher on north than on south slope, but with plant species-dependent trends. Our work showed how the environmental heterogeneity at microscale in alpine systems (slope and plant species identity) underlies variations in the abundance and plant growth promoting activity of the microorganisms present under the plant canopy of the Andean xerophytic formations and highlight the importance of PGPB from harsh systems as biotechnological tools for restoration.

Osmotic characteristics of water retention structures of Bursera microphylla in relation to soil salinity

With a worldwide increase in soil salinity, as well as the climate crisis raising global temperatures, it is important to understand the effects of soil salinity on plant survival. One way to understand how plants may evolve to survive in these xeric desert environments is to gain a further understanding of existing halophytic (live in saline environments) and/or xerophytic (live in dry, arid environments) plants. Bursera microphylla in particular is quite interesting because it is both a halophyte and a xerophyte. One reason it is able to survive in dry environments is due to its bulbs at the base of the trunk and major limbs of the tree, which have been shown to store water during droughts. To facilitate mineral uptake, plants use ATP to transport NaCl ions into the plant, which facilitates water uptake. Because observed field conditions in the Baja California Peninsula were extremely xeric, most plants there have distinct evolutionary traits to facilitate water storage or retention. The Elephant Tree (Bursera microphylla) gets its name from the abnormal proportions of the base of its stem, which is much wider than much of the tree, and studies show that this disproportionately wide stem can store water for use during times of drought, which are common in the Baja California Peninsula. Our hypothesis was that sodium chloride was taken up through the plant’s root structure to facilitate this water transportation, and that this sodium chloride accumulation was directly proportional to the soil salinity. We tested this hypothesis via light microscopy of plant tissues to observe cell tonicity under different concentrations of saline solution. soil salinity was measured using saturated extraction. The results of this experiment show that most cells within the “bulb” structures were isotonic at a concentration approximately twice as high as that of root tissue and ambient soil salinity, therefore supporting the presented hypothesis.

ACC deaminase-producing endophytic fungal consortia promotes drought stress tolerance in M.oleifera by mitigating ethylene and H2O2.

Drought has become more prevalent due to dramatic climate change worldwide. Consequently, the most compatible fungal communities collaborate to boost plant development and ecophysiological responses under environmental constraints. However, little is known about the specific interactions between non-host plants and endophytic fungal symbionts that produce growth-promoting and stress-alleviating hormones during water deficits. The current research was rationalized and aimed at exploring the influence of the newly isolated, drought-resistant, ACC deaminase enzyme-producing endophytic fungi Trichoderma gamsii (TP), Fusarium proliferatum (TR), and its consortium (TP+TR) from a xerophytic plant Carthamus oxycantha L. on Moringa oleifera L. grown under water deficit induced by PEG-8000 (8% osmoticum solution). The current findings revealed that the co-inoculation promoted a significant enhancement in growth traits such as dry weight (217%), fresh weight (123%), root length (65%), shoot length (53%), carotenoids (87%), and chlorophyll content (76%) in comparison to control plants under water deficit. Total soluble sugars (0.56%), proteins (132%), lipids (43%), flavonoids (52%), phenols (34%), proline (55%), GA3 (86%), IAA (35%), AsA (170%), SA (87%), were also induced, while H2O2 (-45%), ABA (-60%) and ACC level (-77%) was decreased by co-inoculation of TP and TR in M. oleifera plants, compared with the non-inoculated plants under water deficit. The co-inoculum (TP+TR) also induced the antioxidant potential and enzyme activities POX (325%), CAT activity (166%), and AsA (21%), along with a lesser decrease (-2%) in water potential in M. oleifera plants with co-inoculation under water deficit compared with non-inoculated control. The molecular analysis for gene expression unraveled the reduced expression of ethylene biosynthesis and signaling-related genes up to an optimal level, with an induction of antioxidant enzymatic genes by endophytic co-inoculation in M. oleifera plants under water deficit, suggesting their role in drought stress tolerance as an essential regulatory function. The finding may alert scientists to consider the impacts of optimal reduction of ethylene and induction of antioxidant potential on drought stress tolerance in M. oleifera. Hence, the present study supports the use of compatible endophytic fungi to build a bipartite mutualistic symbiosis in M. oleifera non-host plants to mitigate the negative impacts of water scarcity in arid regions throughout the world.