Project description:L-Carnitine is an essential compound that shuttles long chain fatty acids into mitochondria. The objective of this study was to produce L-carnitine enriched oyster mushroom (Pleurotus ostreatus) using common buckwheat fermented by Rhizopus oligosporus. Mushroom grown on common buckwheat medium contained 9.9-23.9% higher L-carnitine (186.3 mg/kg) than those grown on basal medium without any buckwheat addition. Those grown on fermented common buckwheat medium contained the highest L-carnitine content (201.2 mg/kg). Size index and lightness of mushroom pileus (L*) were also the highest (100.7 and 50.6, respectively) for those grown in medium added with fermented common buckwheat (20%, w/w). Antioxidant activities of both mushroom extracts (1.5 mg/mL) showed the same level as 38.7% for mushroom grown in media added with common buckwheat or fermented common buckwheat. At the treatment concentration of 300 ?g/mL, viabilities of murine macrophage cell line Raw 264.7 cells treated with ethanol extract of oyster mushroom grown on buckwheat medium ranged from 58.9 to 67.8%. The oyster mushroom grown on buckwheat and fermented buckwheat medium can be used as one of the substitutes for meat based diets.
Project description:<h4>Background and aims</h4>Aluminium (Al) toxicity and drought are two major limiting factors for common bean (Phaseolus vulgaris) production on tropical acid soils. Polyethylene glycol (PEG 6000)-induced osmotic stress (OS) simulating drought stress reduces Al accumulation in the entire root tips of common bean by alteration of cell-wall (CW) porosity, which might be regulated by two genes encoding xyloglucan endotransglucosylase/hydrolase, PvXTH9 and PvXTHb The aim of this research was to understand the spatial and temporal regulation of both XTH genes in PEG-mediated Al accumulation in the root tips.<h4>Methods</h4>In this study the spatial and temporal expression patterns of Al-inhibited root elongation, Al accumulation, XTH gene expression and xyloglucan endotransglucosylase (XET) enzyme action in the root tips were analysed under PEG-induced OS by a combination of physiological and molecular approaches such as quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and in situ fluorescence detection of XET in root tips.<h4>Key results</h4>The results showed that Al accumulation, expression of XTH genes and XET action were distinctly reduced in the apical 0-2, 2-7 and 7-12?mm zones under OS, implying a potential regulatory role of XTH genes and XET enzyme in CW Al accumulation in these zones.<h4>Conclusions</h4>The results provide novel insights into the physiological and molecular mechanisms of CW structure modification as a response of plant roots to OS, which will contribute to mitigate Al and drought stresses, severely limiting crop yields on acid soils.
Project description:bZIP transcription factors have been reported to be involved in many different biological processes in plants. The ABA (abscisic acid)-dependent AREB/ABF-SnRK2 pathway has been shown to play a key role in the response to osmotic stress in model plants. In this study, a novel bZIP gene, FtbZIP5, was isolated from tartary buckwheat, and its role in the response to drought and salt stress was characterized by transgenic Arabidopsis. We found that FtbZIP5 has transcriptional activation activity, which is located in the nucleus and specifically binds to ABRE elements. It can be induced by exposure to PEG6000, salt and ABA in tartary buckwheat. The ectopic expression of FtbZIP5 reduced the sensitivity of transgenic plants to drought and high salt levels and reduced the oxidative damage in plants by regulating the antioxidant system at a physiological level. In addition, we found that, under drought and salt stress, the expression levels of several ABA-dependent stress response genes (RD29A, RD29B, RAB18, RD26, RD20 and COR15) in the transgenic plants increased significantly compared with their expression levels in the wild type plants. Ectopic expression of FtbZIP5 in Arabidopsis can partially complement the function of the ABA-insensitive mutant abi5-1 (abscisic acid-insensitive 5-1). Moreover, we screened FtSnRK2.6, which might phosphorylate FtbZIP5, in a yeast two-hybrid experiment. Taken together, these results suggest that FtbZIP5, as a positive regulator, mediates plant tolerance to salt and drought through ABA-dependent signaling pathways.
Project description:To overcome environmental stress, plants develop physiological responses that are triggered by genetic or epigenetic changes, some of which involve DNA methylation. It has been proposed that apomixis, the formation of asexual seeds without meiosis, occurs through the temporal or spatial deregulation of the sexual process mediated by genetic and epigenetic factors influenced by the environment. Here, we explored whether there was a link between the occurrence of apomixis and various factors that generate stress, including drought stress, in vitro culture, and intraspecific hybridization. For this purpose, we monitored the embryo sacs of different weeping lovegrass (Eragrostis curvula [Schrad.] Nees) genotypes after the plants were subjected to these stress conditions. Progeny tests based on molecular markers and genome methylation status were analyzed following the stress treatment. When grown in the greenhouse, the cultivar Tanganyika INTA generated less than 2% of its progeny by sexual reproduction. Plants of this cultivar subjected to different stresses showed an increase of sexual embryo sacs, demonstrating an increased expression of sexuality compared to control plants. Plants of the cv. Tanganyika USDA did not demonstrate the ability to generate sexual embryo sacs under any conditions and is therefore classified as a fully apomictic cultivar. We found that this change in the prevalence of sexuality was correlated with genetic and epigenetic changes analyzed by MSAP and AFLPs profiles. Our results demonstrate that different stress conditions can alter the expression of sexual reproduction in facultative tetraploid apomictic cultivars and when the stress stops the reproductive mode shift back to the apomixis original level. These data together with previous observations allow us to generate a hypothetical model of the regulation of apomixis in weeping lovegrass in which the genetic/s region/s that condition apomixis, is/are affected by ploidy, and is/are subjected to epigenetic control.
Project description:BACKGROUND:Guayule (Parthenium argentatum Gray) is a drought tolerant, rubber producing perennial shrub native to northern Mexico and the US Southwest. Hevea brasiliensis, currently the world's only source of natural rubber, is grown as a monoculture, leaving it vulnerable to both biotic and abiotic stressors. Isolation of rubber from guayule occurs by mechanical harvesting of the entire plant. It has been reported that environmental conditions leading up to harvest have a profound impact on rubber yield. The link between rubber biosynthesis and drought, a common environmental condition in guayule's native habitat, is currently unclear. RESULTS:We took a transcriptomic and comparative genomic approach to determine how drought impacts rubber biosynthesis in guayule. We compared transcriptional profiles of stem tissue, the location of guayule rubber biosynthesis, collected from field-grown plants subjected to water-deficit (drought) and well-watered (control) conditions. Plants subjected to the imposed drought conditions displayed an increase in production of transcripts associated with defense responses and water homeostasis, and a decrease in transcripts associated with rubber biosynthesis. An evolutionary and comparative analysis of stress-response transcripts suggests that more anciently duplicated transcripts shared among the Asteraceae, rather than recently derived duplicates, are contributing to the drought response observed in guayule. In addition, we identified several deeply conserved long non-coding RNAs (lncRNAs) containing microRNA binding motifs. One lncRNA in particular, with origins at the base of Asteraceae, may be regulating the vegetative to reproductive transition observed in water-stressed guayule by acting as a miRNA sponge for miR166. CONCLUSIONS:These data represent the first genomic analyses of how guayule responds to drought like conditions in agricultural production settings. We identified an inverse relationship between stress-responsive transcripts and those associated with precursor pathways to rubber biosynthesis suggesting a physiological trade-off between maintaining homeostasis and plant productivity. We also identify a number of regulators of abiotic responses, including transcription factors and lncRNAs, that are strong candidates for future projects aimed at modulating rubber biosynthesis under water-limiting conditions common to guayules' native production environment.
Project description:Common buckwheat (Fagopyrum esculentum Moench) is a robust plant with high resistance to different environmental constraints. It contains high levels of calcium oxalate (CaOx) druse crystals, although their role remains obscure. The objective was to examine the effects of water shortage on plant biomass partition and leaf traits and formation of CaOx druse crystals in common buckwheat. Buckwheat plants were exposed to favorable and reduced water availability for 28 days. The element composition and morphological, biochemical, physiological and optical traits of the leaves, and the plant biomass were investigated under these conditions. Measurements of photochemical efficiency of photosystem II showed undisturbed functioning for buckwheat exposed to water shortage, apparently due to partially closed stomata and more efficient water regulation. Strong relationships were seen between water-related parameters and Ca, Mn and S content, and size and density of CaOx druse crystals. Redundancy analysis revealed the importance of the size of CaOx druse crystals to explain reflection in the UV range. Water shortage resulted in shorter plants with the same leaf mass (i.e., increased mass:height ratio), which, together with denser leaf tissue and higher content of photosynthetic pigments and protective substances, provides an advantage under extreme weather conditions.
Project description:Drought is the major environmental stress that limits cotton (Gossypium hirsutum L.) production worldwide. LOS5/ABA3 (LOS5) encodes a molybdenum co-factor and is essential for activating aldehyde oxidase, which is involved in abscisic acid (ABA) biosynthesis. In this study, a LOS5 cDNA of Arabidopsis thaliana was overexpressed in cotton cultivar Zhongmiansuo35 (Z35) by Agrobacterium tumefaciens-mediated transformation. The transformation and overexpression of AtLOS5 were assessed by PCR and RT-PCR analysis. Detached shoots of transgenic cotton showed slower transpirational water loss than those of Z35. When pot-grown 6-week-old seedlings were withheld from watering for 3 d, transgenic cotton accumulated 25% more endogenous ABA and about 20% more proline than Z35 plants. The transgenic plants also showed increased expression of some drought-responding genes such as P5CS and RD22, and enhanced activity of antioxidant enzymes such as superoxide dismutase, peroxidase, and ascorbate peroxidase. Their membrane integrity was considerably improved under water stress, as indicated by reduced malondialdehyde content and electrolyte leakage relative to control plants. When the pot-grown plants were subjected to deficit irrigation for 8 weeks (watering to 50% of field capacity), transgenic plants showed a 13% increase in fresh weight than the wild type under the same drought condition. These results suggest that the AtLOS5 transgenic cotton plants acquired a better drought tolerance through enhanced ABA production and ABA-induced physiological regulations.
Project description:Environmental stress factors caused by climate change affect plant growth and crop production, and pose a growing threat to sustainable agriculture, especially for tree crops. In this context, we sought to investigate the responses to climate change of two Prunus rootstocks (GF677 and Adesoto) budded with Catherina peach cultivar. Plants were grown in 15 L pots in temperature gradient greenhouses for an 18 days acclimation period after which six treatments were applied: [CO2 levels (400 versus 700 µmol mol-1), temperature (ambient versus ambient + 4°C), and water availability (well irrigated versus drought)]. After 23 days, the effects of stress were evaluated as changes in physiological and biochemical traits, including expression of relevant genes. Stem water potential decreased under drought stress in plants grafted on GF677 and Adesoto rootstocks; however, elevated CO2 and temperature affected plant water content differently in both combinations. The photosynthetic rate of plants grafted on GF677 increased under high CO2, but decreased under high temperature and drought conditions. The photosynthetic rates of plants grafted onto Adesoto were only affected by drought treatment. Furthermore, in GF677-Catherina plants, elevated CO2 alleviated the effect of drought, whereas in those grafted onto Adesoto, the same condition produced acclimation in the rate. Stomatal conductance decreased under high CO2 and drought stress in both grafted rootstocks, and the combination of these conditions improved water-use efficiency. Changes in the sugar content in scion leaves and roots were significantly different under the stress conditions in both combinations. Meanwhile, the expression of most of the assessed genes was significantly affected by treatment. Regarding genotypes, GF677 rootstock showed more changes at the molecular and transcriptomic level than did Adesoto rootstock. A coordinated shift was found between the physiological status and the transcriptomic responses. This study revealed adaptive responses to climate change at the physiological, metabolic, and transcriptomic levels in two Prunus rootstocks budded with 'Catherina'. Overall, these results demonstrate the resilient capacity and plasticity of these contrasting genotypes, which can be further used to combat ongoing climate changes and support sustainable peach production.
2020-01-01 | S-EPMC7059187 | BioStudies
Project description:drought responsive transcriptome of common buckwheat
Project description:BACKGROUND:Recurrent drought associated with climate change is a major constraint to wheat (Triticum aestivum L.) productivity. This study aimed to (i) quantify the effects of addition/substitution/translocation of chromosome segments from wild relatives of wheat on the root, physiological and yield traits of hexaploid wheat under drought, and (ii) understand the mechanism(s) associated with drought tolerance or susceptibility in wheat-alien chromosome lines. METHODS:A set of 48 wheat-alien chromosome lines (addition/substitution/translocation lines) with Chinese Spring background were used. Seedling root traits were studied on solid agar medium. To understand the influence of drought on the root system of adult plants, these 48 lines were grown in 150-cm columns for 65 d under full irrigation or withholding water for 58 d. To quantify the effect of drought on physiological and yield traits, the 48 lines were grown in pots under full irrigation until anthesis; after that, half of the plants were drought stressed by withholding water for 16 d before recording physiological and yield-associated traits. RESULTS:The alien chromosome lines exhibited altered root architecture and decreased photochemical efficiency and seed yield and its components under drought. The wheat-alien chromosome lines T5DS·5S#3L (TA5088) with a chromosome segment from Aegilops speltoides (5S) and T5DL.5 V#3S (TA5638) with a chromosome segment from Dasypyrum villosum (5 V) were identified as drought tolerant, and the drought tolerance mechanism was associated with a deep, thin and profuse root system. CONCLUSIONS:The two germplasm lines (TA5088 and TA5638) could be used in wheat breeding programs to improve drought tolerance in wheat and understand the underlying molecular genetic mechanisms of root architecture and drought tolerance.