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Methods in Molecular Biology (Clifton,... 2024High temperature is one of the most devastating environmental factors that severely impede plant growth multi-laterally and threatens global food security. Global...
High temperature is one of the most devastating environmental factors that severely impede plant growth multi-laterally and threatens global food security. Global warming and the predicted steady rise in temperature emphasize the urgent need to improve heat stress resilience of crop plants to meet the growing food demand. Although known for several years, a memory-based mechanism termed "priming-induced stress tolerance" or "acquired stress tolerance" has gained the attention of the plant science community in recent years. Thermopriming is one such phenomenon that enhances the plant tolerance to subsequent heat stress and promotes growth. The memory of the foregoing mild increase in temperature is captured and retained as dormant signals, which upon exposure to subsequent high temperature aids in mounting a faster, stronger, and sensitized response. Such acquired thermotolerance is more effective than the basal endurance of the plant due to altered molecular regulatory networks. Thereupon, thermopriming can be used as a convenient tool to study and improve plant response to heat stress. In this chapter, the protocol to study thermopriming-mediated short- and long-term acquired thermotolerance is described in detail.
Topics: Arabidopsis; Thermotolerance; Heat-Shock Response; Gene Expression Regulation, Plant; Hot Temperature
PubMed: 38869799
DOI: 10.1007/978-1-0716-3973-3_16 -
Methods in Molecular Biology (Clifton,... 2024Plant growth and survival in their natural environment require versatile mitigation of diverse threats. The task is especially challenging due to the largely... (Review)
Review
Plant growth and survival in their natural environment require versatile mitigation of diverse threats. The task is especially challenging due to the largely unpredictable interaction of countless abiotic and biotic factors. To resist an unfavorable environment, plants have evolved diverse sensing, signaling, and adaptive molecular mechanisms. Recent stress studies have identified molecular elements like secondary messengers (ROS, Ca, etc.), hormones (ABA, JA, etc.), and signaling proteins (SnRK, MAPK, etc.). However, major gaps remain in understanding the interaction between these pathways, and in particular under conditions of stress combinations. Here, we highlight the challenge of defining "stress" in such complex natural scenarios. Therefore, defining stress hallmarks for different combinations is crucial. We discuss three examples of robust and dynamic plant acclimation systems, outlining specific plant responses to complex stress overlaps. (a) The high plasticity of root system architecture is a decisive feature in sustainable crop development in times of global climate change. (b) Similarly, broad sensory abilities and apparent control of cellular metabolism under adverse conditions through retrograde signaling make chloroplasts an ideal hub. Functional specificity of the chloroplast-associated molecular patterns (ChAMPs) under combined stresses needs further focus. (c) The molecular integration of several hormonal signaling pathways, which bring together all cellular information to initiate the adaptive changes, needs resolving.
Topics: Acclimatization; Signal Transduction; Stress, Physiological; Plants; Plant Growth Regulators; Chloroplasts; Plant Physiological Phenomena; Gene Expression Regulation, Plant; Plant Roots
PubMed: 38869784
DOI: 10.1007/978-1-0716-3973-3_1 -
Anaerobe Jun 2024This lab-scale study aimed to investigate the effect of total ammonia nitrogen (TAN) stress on the methanogenic activity and the taxonomic and functional profiles of the...
OBJECTIVES
This lab-scale study aimed to investigate the effect of total ammonia nitrogen (TAN) stress on the methanogenic activity and the taxonomic and functional profiles of the microbial community of anaerobic sludge (AS) from a full-scale bioreactor.
METHODS
The AS was subjected to a stepwise increase in TAN every 14 days at concentrations of 1, 2, 2.5, 3, 3.5, and 4 g-TAN/L (Acclimated-AS or AAS). This acclimation stage was followed by an ammonia stress stage (4 g/L). A blank-AS (BAS) was maintained without TAN during the acclimation stage. In the second stress stage (ST), the BAS was divided into two new treatments: a control (BAS') and one that received a shock load of TAN of 4 g/L (SBAS'). Methane production was measured, and a metagenomic analysis was conducted to describe the microbial community.
RESULTS
A decrease in the relative abundance of Methanothrix soehngenii of 16% was related to a decrease of 23% in the methanogenic capacity of AAS when comparing with the final stage of BAS. However, recovery was observed at 3.5 g TAN/L, and a shift to methylotrophic metabolism occurred, indicated by a 4-fold increase in abundance of Methanosarcina mazei. The functional analysis of sludge metagenomes indicated that no statistical differences (p > 0.05, RM ANOVA) were found in the relative abundance of methanogenic genes that initiate acetoclastic and hydrogenotrophic pathways (acetyl-CoA synthetase, ACSS; acetate kinase, ackA; phosphate acetyltransferase, pta; and formylmethanofuran dehydrogenase subunit A, fwdA) into the BAS and AAS during the acclimation phase. The same was observed between groups of genes associated with methanogenesis from methylated compounds. In contrast, statistical differences (p < 0.05, one-way ANOVA) in the relative abundance of these genes were recorded during ST. The functional profiles of the genes involved in acetoclastic, hydrogenotrophic, and methylotrophic methanogenic pathways were brought to light for acclimatation and stress experimental stages.
CONCLUSIONS
TAN inhibited methanogenic activity and acetoclastic metabolism. The gradual acclimatization to TAN leads to metabolic and taxonomic changes that allow for the subsequent recovery of methanogenic functionality. The study highlights the importance of adequate management of anaerobic bioprocesses with high nitrogen loads to maintain the methanogenic functionality of the microbial community.
PubMed: 38866129
DOI: 10.1016/j.anaerobe.2024.102877 -
Science Advances Jun 2024Certain cyanobacteria alter their photosynthetic light absorption between green and red, a phenomenon called complementary chromatic acclimation. The acclimation is...
Certain cyanobacteria alter their photosynthetic light absorption between green and red, a phenomenon called complementary chromatic acclimation. The acclimation is regulated by a cyanobacteriochrome-class photosensor that reversibly photoconverts between green-absorbing (Pg) and red-absorbing (Pr) states. Here, we elucidated the structural basis of the green/red photocycle. In the Pg state, the bilin chromophore adopted the extended C15-, structure within a hydrophobic pocket. Upon photoconversion to the Pr state, the bilin is isomerized to the cyclic C15-, structure, forming a water channel in the pocket. The solvation/desolvation of the bilin causes changes in the protonation state and the stability of π-conjugation at the B ring, leading to a large absorption shift. These results advance our understanding of the enormous spectral diversity of the phytochrome superfamily.
Topics: Light; Cyanobacteria; Acclimatization; Photosynthesis; Phytochrome; Models, Molecular; Bile Pigments; Bacterial Proteins; Red Light
PubMed: 38865454
DOI: 10.1126/sciadv.adn8386 -
Plant Cell Reports Jun 202463 L. bicolor WRKY genes were identified and their informatics was analyzed. The results suggested that the LbWRKY genes involved in the development and salt secretion...
63 L. bicolor WRKY genes were identified and their informatics was analyzed. The results suggested that the LbWRKY genes involved in the development and salt secretion of salt glands in L. bicolor. Salt stress, as a universal abiotic stress, severely inhibits the growth and development of plants. WRKY transcription factors play a vital role in plant growth and development, as well as in response to various stresses. Nevertheless, little is known of systematic genome-wide analysis of the WRKY genes in Limonium bicolor, a model recretohalophyte. In this study, 63 L. bicolor WRKY genes were identified (LbWRKY1-63), which were unevenly distributed across seven chromosomes and one scaffold. Based on the structural and phylogenetic characteristics, 63 LbWRKYs are divided into three main groups. Cis-elements in the LbWRKY promoters were related to growth and development, phytohormone responses, and stress responses. Colinearity analysis showed strong colinearity between LbWRKYs and GmWRKYs from soybean (Glycine max). Therefore, LbWRKY genes maybe have similar functions to GmWRKY genes. Expression analysis showed that 28 LbWRKY genes are highly expressed in roots, 9 in stems, 26 in leaves, and 12 in flowers and most LbWRKY genes responded to NaCl, ABA, and PEG6000. Silencing LbWRKY10 reduced salt gland density and salt secretion ability of leaves, and the salt tolerance of the species. Consistent with this, genes associated with salt gland development were markedly down-regulated in the LbWRKY10-silenced lines. Our findings suggested that the LbWRKY genes involved in the development and salt secretion of salt glands in L. bicolor. Our research provides new insights into the functions of the WRKY family in halophytes.
Topics: Plumbaginaceae; Gene Expression Regulation, Plant; Salt-Tolerant Plants; Plant Proteins; Phylogeny; Transcription Factors; Salt Tolerance; Multigene Family; Salt Stress; Stress, Physiological; Plants, Genetically Modified; Promoter Regions, Genetic; Genes, Plant
PubMed: 38865016
DOI: 10.1007/s00299-024-03258-z -
BMC Plant Biology Jun 2024BRVIS RADIX (BRX) family is a small gene family with the highly conserved plant-specific BRX domains, which plays important roles in plant development and response to...
BACKGROUND
BRVIS RADIX (BRX) family is a small gene family with the highly conserved plant-specific BRX domains, which plays important roles in plant development and response to abiotic stress. Although BRX protein has been studied in other plants, the biological function of cotton BRX-like (BRXL) gene family is still elusive.
RESULT
In this study, a total of 36 BRXL genes were identified in four cotton species. Whole genome or segmental duplications played the main role in the expansion of GhBRXL gene family during evolutionary process in cotton. These BRXL genes were clustered into 2 groups, α and β, in which structural and functional conservation within same groups but divergence among different groups were found. Promoter analysis indicated that cis-elements were associated with the phytohormone regulatory networks and the response to abiotic stress. Transcriptomic analysis indicated that GhBRXL2A/2D and GhBRXL5A/5D were up/down-regulated in response to the different stress. Silencing of GhBRXL5A gene via virus-induced gene silencing (VIGS) improved salt tolerance in cotton plants. Furthermore, yeast two hybrid analysis suggested homotypic and heterotypic interactions between GhBRXL1A and GhBRXL5D.
CONCLUSIONS
Overall, these results provide useful and valuable information for understanding the evolution of cotton GhBRXL genes and their functions in salt stress.
Topics: Gossypium; Multigene Family; Plant Proteins; Salt Stress; Gene Expression Regulation, Plant; Salt Tolerance; Phylogeny; Genes, Plant; Gene Expression Profiling
PubMed: 38862893
DOI: 10.1186/s12870-024-05220-3 -
World Journal of Microbiology &... Jun 2024Anaerobic digestion (AD) emerges as a pivotal technique in climate change mitigation, transforming organic materials into biogas, a renewable energy form. This process...
Anaerobic digestion (AD) emerges as a pivotal technique in climate change mitigation, transforming organic materials into biogas, a renewable energy form. This process significantly impacts energy production and waste management, influencing greenhouse gas emissions. Traditional research has largely focused on anaerobic bacteria and methanogens for methane production. However, the potential of anaerobic lignocellulolytic fungi for degrading lignocellulosic biomass remains less explored. In this study, buffalo rumen inocula were enriched and acclimatized to improve lignocellulolytic hydrolysis activity. Two consortia were established: the anaerobic fungi consortium (AFC), selectively enriched for fungi, and the anaerobic lignocellulolytic microbial consortium (ALMC). The consortia were utilized to create five distinct microbial cocktails-AF0, AF20, AF50, AF80, and AF100. These cocktails were formulated based on varying of AFC and ALMC by weights (w/w). Methane production from each cocktail of lignocellulosic biomasses (cassava pulp and oil palm residues) was evaluated. The highest methane yields of CP, EFB, and MFB were obtained at 337, 215, and 54 mL/g VS, respectively. Cocktails containing a mix of anaerobic fungi, hydrolytic bacteria (Sphingobacterium sp.), syntrophic bacteria (Sphaerochaeta sp.), and hydrogenotrophic methanogens produced 2.1-2.6 times higher methane in cassava pulp and 1.1-1.2 times in oil palm empty fruit bunch compared to AF0. All cocktails effectively produced methane from oil palm empty fruit bunch due to its lipid content. However, methane production ceased after 3 days when oil palm mesocarp fiber was used, due to long-chain fatty acid accumulation. Anaerobic fungi consortia showed effective lignocellulosic and starchy biomass degradation without inhibition due to organic acid accumulation. These findings underscore the potential of tailored microbial cocktails for enhancing methane production from diverse lignocellulosic substrates.
Topics: Methane; Anaerobiosis; Lignin; Fungi; Microbial Consortia; Animals; Biomass; Rumen; Biofuels; Hydrolysis; Fermentation; Bacteria; Industrial Waste; Agriculture
PubMed: 38862848
DOI: 10.1007/s11274-024-04050-7 -
Antonie Van Leeuwenhoek Jun 2024Strain MP-1014, an obligate halophilic actinobacterium, was isolated from the mangrove soil of Thandavarayancholanganpettai, Tamil Nadu, India. A polyphasic approach was...
Isoptericola haloaureus sp. nov., a dimorphic actinobacterium isolated from mangrove sediments of southeast India, implicating biosaline agricultural significance through nitrogen fixation and salt tolerance genes.
Strain MP-1014, an obligate halophilic actinobacterium, was isolated from the mangrove soil of Thandavarayancholanganpettai, Tamil Nadu, India. A polyphasic approach was utilized to explore its phylogenetic position completely. The isolate was Gram-positive, filamentous, non-motile, and coccoid in older cultures. Ideal growth conditions were seen at 30 °C and pH 7.0, with 5% NaCl (W/V), and the DNA G + C content was 73.3%. The phylogenic analysis of this strain based upon 16S rRNA gene sequence revealed 97-99.8% similarity to the recognized species of the genus Isoptericola. Strain MP-1014 exhibits the highest similarity to I. sediminis JC619 (99.7%), I. chiayiensis KCTC19740 (98.9%), and subsequently to I. halotolerans KCTC19646 (98.6%), when compared with other members within the Isoptericola genus (< 98%). ANI scores of strain MP-1014 are 86.4%, 84.2%, and 81.5% and dDDH values are 59.7%, 53.6%, and 34.8% with I. sediminis JC619, I. chiayiensis KCTC19740 and I. halotolerans KCTC19646 respectively. The major polar lipids of the strain MP-1014 were phosphatidylinositol, phosphatidylglycerol, diphosphotidylglycerol, two unknown phospholipids, and glycolipids. The predominant respiratory menaquinones were MK (H) and MK (H). The major fatty acids were anteiso-C, anteiso-C, iso-C, C and C. Also, initial genome analysis of the organism suggests it as a biostimulant for enhancing agriculture in saline environments. Based on phenotypic and genetic distinctiveness, the strain MP-1014 represents the novel species of the genus Isoptericola assigned Isoptericola haloaureus sp. nov., is addressed by the strain MP-1014 , given its phenotypic, phylogenetic, and hereditary uniqueness. The type strain is MP-1014 [(NCBI = OP672482.1 = GCA_036689775.1) ATCC = BAA 2646; DSMZ = 29325; MTCC = 13246].
Topics: India; Phylogeny; RNA, Ribosomal, 16S; Salt Tolerance; DNA, Bacterial; Base Composition; Nitrogen Fixation; Wetlands; Fatty Acids; Geologic Sediments; Bacterial Typing Techniques; Soil Microbiology; Phospholipids; Sequence Analysis, DNA; Sodium Chloride; Actinobacteria
PubMed: 38861000
DOI: 10.1007/s10482-024-01985-7 -
Wilderness & Environmental Medicine Jun 2024Griffith Pugh, MD (1909-1994), was a pioneer in altitude physiology. During World War II, he developed training protocols in Lebanon to improve soldier performance at...
Griffith Pugh, MD (1909-1994), was a pioneer in altitude physiology. During World War II, he developed training protocols in Lebanon to improve soldier performance at altitude and in the cold. In 1951 he was chosen to join the British Everest team as a scientist. In preparation, he developed strategies for success on a training expedition on Cho Oyu in 1952. Results from Cho Oyu led to the use of supplemental oxygen at higher flow rates during ascent than used previously (4 L/min vs 2 L/min) and continued use (at a reduced rate of 2 L/min) during descent, enabling increased performance and improved mental acuity. Oxygen was also used during sleep, leading to improved sleep and warmth. Adequate hydration (∼3 L/day) was also stressed, and a more appealing diet led to improved nutrition and condition of the climbers. Improved hygiene practices and acclimatization protocols were also developed. These strategies contributed to the first successful summiting of Mount Everest in 1953. Pugh was then appointed as the lead scientist for a ground-breaking eight-and-a-half-month research expedition where the team was the first to overwinter at high altitude (5800 m) in the Himalayas. This current work summarizes Pugh's scientific contributions as they relate to success on Mount Everest and in inspiring future altitude research by generations of successful researchers.
PubMed: 38860547
DOI: 10.1177/10806032241259499 -
Physiologia Plantarum 2024The effects of transient increases in UVB radiation on plants are not well known; whether cumulative damage dominates or, alternately, an increase in photoprotection and...
The effects of transient increases in UVB radiation on plants are not well known; whether cumulative damage dominates or, alternately, an increase in photoprotection and recovery periods ameliorates any negative effects. We investigated photosynthetic capacity and metabolite accumulation of grapevines (Vitis vinifera Cabernet Sauvignon) in response to UVB fluctuations under four treatments: fluctuating UVB (FUV) and steady UVB radiation (SUV) at similar total biologically effective UVB dose (2.12 and 2.23 kJ m day), and their two respective no UVB controls. We found a greater decrease in stomatal conductance under SUV than FUV. There was no decrease in maximum yield of photosystem II (F/F) or its operational efficiency (ɸ) under the two UVB treatments, and F/F was higher under SUV than FUV. Photosynthetic capacity was enhanced under FUV in the light-limited region of rapid light-response curves but enhanced by SUV in the light-saturated region. Flavonol content was similarly increased by both UVB treatments. We conclude that, while both FUV and SUV effectively stimulate acclimation to UVB radiation at realistic doses, FUV confers weaker acclimation than SUV. This implies that recovery periods between transient increases in UVB radiation reduce UVB acclimation, compared to an equivalent dose of UVB provided continuously. Thus, caution is needed in interpreting the findings of experiments using steady UVB radiation treatments to infer effects in natural environments, as the stimulatory effect of steady UVB is greater than that of the equivalent fluctuating UVB.
Topics: Photosynthesis; Ultraviolet Rays; Acclimatization; Vitis; Photosystem II Protein Complex; Chlorophyll; Plant Stomata; Flavonols
PubMed: 38859677
DOI: 10.1111/ppl.14383