RESUMO
Microbial inoculation plays a significant role in promoting the efficiency of biowaste conversion. This study investigates the function of Streptomyces-Bacillus Inoculants (SBI) on carbon (C) and nitrogen (N) conversion, and microbial dynamics, during cow manure (10% and 20% addition) and corn straw co-composting. Compared to inoculant-free controls, inoculant application accelerated the compost's thermophilic stage (8 vs 15 days), and significantly increased compost total N contents (+47%) and N-reductase activities (nitrate reductase: +60%; nitrite reductase: +219%). Both bacterial and fungal community succession were significantly affected by DOC, urease, and NH4+-N, while the fungal community was also significantly affected by cellulase. The contribution rate of Cupriavidus to the physicochemical factors of compost was as high as 83.40%, but by contrast there were no significantly different contributions (â¼60%) among the top 20 fungal genera. Application of SBI induced significant correlations between bacteria, compost C/N ratio, and catalase enzymes, indicative of compost maturation. We recommend SBI as a promising bio-composting additive to accelerate C and N turnover and high-quality biowaste maturation. SBI boosts organic cycling by transforming biowastes into bio-fertilizers efficiently. This highlights the potential for SBI application to improve plant growth and soil quality in multiple contexts.
Assuntos
Carbono , Compostagem , Nitrogênio , Streptomyces , Streptomyces/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo , Esterco , Bacillus/metabolismo , Bactérias/metabolismoRESUMO
The phytohormone jasmonate (JA) coordinates stress and growth responses to increase plant survival in unfavorable environments. Although JA can enhance plant UV-B stress tolerance, the mechanisms underlying the interaction of UV-B and JA in this response remain unknown. In this study, we demonstrate that the UV RESISTANCE LOCUS 8 - TEOSINTE BRANCHED1, Cycloidea and PCF 4 - LIPOXYGENASE2 (UVR8-TCP4-LOX2) module regulates UV-B tolerance dependent on JA signaling pathway in Arabidopsis thaliana. We show that the nucleus-localized UVR8 physically interacts with TCP4 to increase the DNA-binding activity of TCP4 and upregulate the JA biosynthesis gene LOX2. Furthermore, UVR8 activates the expression of LOX2 in a TCP4-dependent manner. Our genetic analysis also provides evidence that TCP4 acts downstream of UVR8 and upstream of LOX2 to mediate plant responses to UV-B stress. Our results illustrate that the UV-B-dependent interaction of UVR8 and TCP4 serves as an important UVR8-TCP4-LOX2 module, which integrates UV-B radiation and JA signaling and represents a new UVR8 signaling mechanism in plants.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ciclopentanos , Regulação da Expressão Gênica de Plantas , Oxilipinas , Raios Ultravioleta , Arabidopsis/efeitos da radiação , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Transdução de Sinais/efeitos da radiação , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Cromossômicas não Histona/genética , Lipoxigenase/metabolismo , Lipoxigenase/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Ligação Proteica/efeitos da radiação , Adaptação Fisiológica/efeitos da radiação , Adaptação Fisiológica/genética , Núcleo Celular/metabolismo , LipoxigenasesRESUMO
Stomata play a fundamental role in modulating the exchange of gases between plants and the atmosphere. These microscopic structures form in high numbers on the leaf epidermis and are also present on flowers. Although leaf stomata are well studied, little attention has been paid to the development or function of floral stomata. Here, we characterize in detail the spatial distribution and development of the floral stomata of the indica rice variety IR64. We show that stomatal complexes are present at low density on specific areas of the lemma, palea and anthers and are morphologically different compared to stomata found on leaves. We reveal that in the bract-like organs, stomatal development follows the same cell lineage transitions as in rice leaves and demonstrate that the overexpression of the stomatal development regulators OsEPFL9-1 and OsEPF1 leads to dramatic changes in stomatal density in rice floral organs, producing lemma with approximately twice as many stomata (OsEPFL9-1_oe) or lemma where stomata are practically absent (OsEPF1_oe). Transcriptomic analysis of developing florets also indicates that the cellular transitions during the development of floral stomata are regulated by the same genetic network used in rice leaves. Finally, although we were unable to detect an impact on plant reproduction linked to changes in the density of floral stomata, we report alterations in global gene expression in lines overexpressing OsEPF1 and discuss how our results reflect on the possible role(s) of floral stomata.
Assuntos
Oryza , Oryza/metabolismo , Redes Reguladoras de Genes , Flores , Folhas de Planta/genética , Expressão Gênica , Estômatos de Plantas/genética , Regulação da Expressão Gênica de PlantasRESUMO
Microbial communities and environmental conditions are both of great importance for efficient utilization of agroforestry resources. Nevertheless, knowledge about the role of soluble nutrients and enzymatic properties, and their inner links with microbial communities remain limited. This is especially the case for the co-composting of agricultural and forestry biowaste. Here, we investigate the succession of key microbes during co-composting (sawdust + cow manure, SA; straw + cow manure, ST), employing amplicon sequencing, enzyme assays, and physicochemical analyses. N-fixing bacteria (Pseudomonas) and C-degrading fungi (Acaulium) have been identified as dominant taxa during such co-composting. Although eight antibiotic resistance genes were found to persist during composting, pathogenic microbes declined with composting time. NO3--N content was screened as a determinant structuring the bacterial and fungal communities, with importance also shown for C-degrading enzymes such as cellulose, laccase, and peroxidase activity. These results identify the key microbial taxa and their main interactive environmental factors, which are potentially valuable for the development of a mixed microbial inoculant to accelerate the maturation of agroforestry biowastes composting.
Assuntos
Compostagem , Micobioma , Animais , Feminino , Bovinos , Esterco/microbiologia , Solo/química , Bactérias/genéticaRESUMO
Truffles contribute to crucial soil systems dynamics, being involved in plentiful ecological functions important for ecosystems. Despite this, the interactions between truffles and their surrounding mycobiome remain unknown. Here, we investigate soil mycobiome differences between two truffle species, Tuber indicum (Ti) and Tuber pseudohimalayense (Tp), and their relative influence on surrounding soil mycobiota. Using traditional chemical analysis and ITS Illumina sequencing, we compared soil nutrients and the mycobiota, respectively, in soil, gleba, and peridium of the two truffle species inhabiting the same Pinus armandii forest in southwestern China. Tp soil was more acidic (pH 6.42) and had a higher nutrient content (total C, N content) than Ti soil (pH 6.62). Fungal richness and diversity of fruiting bodies (ascomata) and surrounding soils were significantly higher in Tp than in Ti. Truffle species recruited unique soil mycobiota around their ascomata: in Ti soil, fungal taxa, including Suillus, Alternaria, Phacidium, Mycosphaerella, Halokirschsteiniothelia, and Pseudogymnoascus, were abundant, while in Tp soil species of Melanophyllum, Inocybe, Rhizopogon, Rhacidium, and Lecanicillium showed higher abundances. Three dissimilarity tests, including adonis, anosim, and MRPP, showed that differences in fungal community structure between the two truffle species and their surrounding soils were stronger in Tp than in Ti, and these differences extended to truffle tissues (peridium and gleba). Redundancy analysis (RDA) further demonstrated that correlations between soil fungal taxa and soil properties changed from negative (Tp) to positive (Ti) and shifted from a moisture-driven (Tp) to a total N-driven (Ti) relationship. Overall, our results shed light on the influence that truffles have on their surrounding soil mycobiome. However, further studies are required on a broader range of truffle species in different soil conditions in order to determine causal relationships between truffles and their soil mycobiome.
Assuntos
Ascomicetos , Micorrizas , Pinus , Ascomicetos/genética , Ecossistema , Florestas , Solo , Microbiologia do SoloRESUMO
The patterning of stomata plays a vital role in plant development and has emerged as a paradigm for the role of peptide signals in the spatial control of cellular differentiation. Research in Arabidopsis has identified a series of epidermal patterning factors (EPFs), which interact with an array of membrane-localised receptors and associated proteins (encoded by ERECTA and TMM genes) to control stomatal density and distribution. However, although it is well-established that stomata arose very early in the evolution of land plants, until now it has been unclear whether the established angiosperm stomatal patterning system represented by the EPF/TMM/ERECTA module reflects a conserved, universal mechanism in the plant kingdom. Here, we use molecular genetics to show that the moss Physcomitrella patens has conserved homologues of angiosperm EPF, TMM and at least one ERECTA gene that function together to permit the correct patterning of stomata and that, moreover, elements of the module retain function when transferred to Arabidopsis Our data characterise the stomatal patterning system in an evolutionarily distinct branch of plants and support the hypothesis that the EPF/TMM/ERECTA module represents an ancient patterning system.
Assuntos
Bryopsida/metabolismo , Estômatos de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Epiderme Vegetal/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologiaRESUMO
Much of humanity relies on rice (Oryza sativa) as a food source, but cultivation is water intensive and the crop is vulnerable to drought and high temperatures. Under climate change, periods of reduced water availability and high temperature are expected to become more frequent, leading to detrimental effects on rice yields. We engineered the high-yielding rice cultivar 'IR64' to produce fewer stomata by manipulating the level of a developmental signal. We overexpressed the rice epidermal patterning factor OsEPF1, creating plants with substantially reduced stomatal density and correspondingly low stomatal conductance. Low stomatal density rice lines were more able to conserve water, using c. 60% of the normal amount between weeks 4 and 5 post germination. When grown at elevated atmospheric CO2 , rice plants with low stomatal density were able to maintain their stomatal conductance and survive drought and high temperature (40°C) for longer than control plants. Low stomatal density rice gave equivalent or even improved yields, despite a reduced rate of photosynthesis in some conditions. Rice plants with fewer stomata are drought tolerant and more conservative in their water use, and they should perform better in the future when climate change is expected to threaten food security.
Assuntos
Secas , Oryza/fisiologia , Estômatos de Plantas/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Dióxido de Carbono , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Oryza/citologia , Oryza/genética , Melhoramento Vegetal , Folhas de Planta/citologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Fatores de Transcrição/genética , Água/metabolismoRESUMO
The fossil record suggests stomata-like pores were present on the surfaces of land plants over 400 million years ago. Whether stomata arose once or whether they arose independently across newly evolving land plant lineages has long been a matter of debate. In Arabidopsis, a genetic toolbox has been identified that tightly controls stomatal development and patterning. This includes the basic helix-loop-helix (bHLH) transcription factors SPEECHLESS (SPCH), MUTE, FAMA, and ICE/SCREAMs (SCRMs), which promote stomatal formation. These factors are regulated via a signaling cascade, which includes mobile EPIDERMAL PATTERNING FACTOR (EPF) peptides to enforce stomatal spacing. Mosses and hornworts, the most ancient extant lineages to possess stomata, possess orthologs of these Arabidopsis (Arabidopsis thaliana) stomatal toolbox genes, and manipulation in the model bryophyte Physcomitrella patens has shown that the bHLH and EPF components are also required for moss stomatal development and patterning. This supports an ancient and tightly conserved genetic origin of stomata. Here, we review recent discoveries and, by interrogating newly available plant genomes, we advance the story of stomatal development and patterning across land plant evolution. Furthermore, we identify potential orthologs of the key toolbox genes in a hornwort, further supporting a single ancient genetic origin of stomata in the ancestor to all stomatous land plants.
Assuntos
Evolução Biológica , Estômatos de Plantas/fisiologia , Arabidopsis/fisiologia , Briófitas/fisiologia , Bryopsida/fisiologia , Regulação da Expressão Gênica de Plantas , Modelos Estatísticos , Família Multigênica , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Plants are sessile organisms. This intriguing nature provokes the question of how they survive despite the continual perturbations caused by their constantly changing environment. The large amount of knowledge accumulated to date demonstrates the fascinating dynamic and plastic mechanisms, which underpin the diverse strategies selected in plants in response to the fluctuating environment. This phenotypic plasticity requires an efficient integration of external cues to their growth and developmental programs that can only be achieved through the dynamic and interactive coordination of various signaling networks. Given the versatility of intrinsic structural disorder within proteins, this feature appears as one of the leading characters of such complex functional circuits, critical for plant adaptation and survival in their wild habitats. In this review, we present information of those intrinsically disordered proteins (IDPs) from plants for which their high level of predicted structural disorder has been correlated with a particular function, or where there is experimental evidence linking this structural feature with its protein function. Using examples of plant IDPs involved in the control of cell cycle, metabolism, hormonal signaling and regulation of gene expression, development and responses to stress, we demonstrate the critical importance of IDPs throughout the life of the plant.
Assuntos
Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Criptocromos/química , Criptocromos/metabolismo , DNA Polimerase Dirigida por DNA/química , DNA Polimerase Dirigida por DNA/metabolismo , Histona Desacetilases/química , Histona Desacetilases/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/química , Transdução de Sinais , Estresse Fisiológico , Fatores de Transcrição/química , Fatores de Transcrição/metabolismoRESUMO
The early evolution of plants required the acquisition of a number of key adaptations to overcome physiological difficulties associated with survival on land. One of these was a tough sporopollenin wall that enclosed reproductive propagules and provided protection from desiccation and UV-B radiation. All land plants possess such walled spores (or their derived homologue, pollen). We took a reverse genetics approach, consisting of knock-out and complementation experiments to test the functional conservation of the sporopollenin-associated gene MALE STERILTY 2 (which is essential for pollen wall development in Arabidopsis thaliana) in the bryophyte Physcomitrella patens. Knock-outs of a putative moss homologue of the A. thaliana MS2 gene, which is highly expressed in the moss sporophyte, led to spores with highly defective walls comparable to that observed in the A. thaliana ms2 mutant, and extremely compromised germination. Conversely, the moss MS2 gene could not rescue the A. thaliana ms2 phenotype. The results presented here suggest that a core component of the biochemical and developmental pathway required for angiosperm pollen wall development was recruited early in land plant evolution but the continued increase in pollen wall complexity observed in angiosperms has been accompanied by divergence in MS2 gene function.
Assuntos
Evolução Biológica , Biopolímeros/biossíntese , Vias Biossintéticas , Carotenoides/biossíntese , Infertilidade das Plantas , Pólen/crescimento & desenvolvimento , Esporos/crescimento & desenvolvimento , Sequência de Aminoácidos , Arabidopsis/genética , Bryopsida/genética , Bryopsida/crescimento & desenvolvimento , Bryopsida/ultraestrutura , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Germinação , Dados de Sequência Molecular , Mutação/genética , Fenótipo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pólen/genética , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Esporos/ultraestruturaRESUMO
Stomata are produced by a controlled series of epidermal cell divisions. The molecular underpinnings of this process are becoming well understood, but mechanisms that determine plasticity of stomatal patterning to many exogenous and environmental cues remain less clear. Light quantity and quality, vapour pressure deficit, soil water content, and CO2 concentration are detected by the plant, and new leaves adapt their stomatal densities accordingly. Mature leaves detect these environmental signals and relay messages to immature leaves to tell them how to adapt and grow. Stomata on mature leaves may act as stress signal-sensing and transduction centres, locally by aperture adjustment, and at long distance by optimizing stomatal density to maximize future carbon gain while minimizing water loss. Although mechanisms of stomatal aperture responses are well characterized, the pathways by which mature stomata integrate environmental signals to control immature epidermal cell fate, and ultimately stomatal density, are not. Here we evaluate current understanding of the latter through the influence of the former. We argue that mature stomata, as key portals by which plants coordinate their carbon and water relations, are controlled by abscisic acid (ABA), both metabolically and hydraulically, and that ABA is also a core regulator of environmentally determined stomatal development.
Assuntos
Ácido Abscísico/metabolismo , Meio Ambiente , Fotossíntese , Reguladores de Crescimento de Plantas/metabolismo , Estômatos de Plantas/fisiologia , Transpiração Vegetal , Plantas/metabolismo , Carbono/metabolismo , Estômatos de Plantas/crescimento & desenvolvimento , Transdução de Sinais , Estresse FisiológicoRESUMO
This study surveyed the fates of artificial sweeteners in influent, effluent, and sewage sludge (SS) in wastewater treatment plant, and investigated the effects of Micro-Kaolin (Micro-KL) and Nano-Kaolin (Nano-KL) on nitrogen transformation and sucralose (SUC) and acesulfame (ACE) degradation during SS composting. Results showed the cumulative rate of ACE and SUC in SS was â¼76 %. During SS composting, kaolin reduced NH3 emissions by 30.2-45.38 %, and N2O emissions by 38.4-38.9 %, while the Micro-KL and Nano-KL reduced nitrogen losses by 14.8 % and 12.5 %, respectively. Meanwhile, Micro-KL and Nano-KL increased ACE degradation by 76.8 % and 84.2 %, and SUC degradation by 75.3 % and 77.7 %, and significantly shifted microbial community structure. Furthermore, kaolin caused a positive association between Actinobacteria and sweetener degradation. Taken together, kaolin effectively inhibited nitrogen loss and promoted the degradation of ACE and SUC during the SS composting, which is of great significance for the removal of emerging organic pollutants in SS.
Assuntos
Compostagem , Caulim , Esgotos , Edulcorantes , Caulim/química , Esgotos/química , Compostagem/métodos , Águas Residuárias/química , Biodegradação Ambiental , Poluentes Químicos da Água , Purificação da Água/métodos , Nitrogênio , Nanopartículas/química , Sacarose/metabolismo , Sacarose/análogos & derivadosRESUMO
Fungal necromass carbon (FNC) contributes significantly to the build-up of soil organic carbon (SOC) by supplying abundant recalcitrant polymeric melanin present in the fungal cell wall. However, the influence of a wide range of conservation practices and associated factors on FNC accumulation and contribution to SOC in global croplands remains unexplored. Here, a meta-analysis was performed using 873 observations across three continents, together with structural equation modeling, to evaluate conservation practices and factors responsible for the enhancement of FNC and SOC. FNC content (8.39 g kg-1) of North American soils was highest compared to FNC content of Asian and European soils. The structural equation models showed a significant (p < 0.05) positive influence of microbial biomass carbon (MBC), soil pH, and clay contents on the accumulation of FNC. Soil C/N ratio and climate factors, however, had only minor influences on FNC accumulation. Notably, the main driver of FNC was MBC, which is mainly influenced by the soil total N and geographic factors in the study areas. Typical 5 cropland practices had significant effect size (p < 0.05) on FNC, leading to an increase of 12 % to 26 %, and the FNC content was greatest under straw amendment (26 %). Fungal necromass accumulation efficiency ranged from 23 % to 45 % depending on cropland practices: non- and reduced tillage was the most efficient (45 %), followed by crop coverage (32 %), straw amendment (30 %), and manure application (27 %), while N fertilization had the lowest efficiency (23 %). We conclude that FNC contributes to over a quarter of SOC, highlighting its major role in enhancing C sequestration worldwide. Conservation practices, particularly non-tillage or reduced tillage, are important to enhance C sequestration from FNC in croplands.
Assuntos
Agricultura , Sequestro de Carbono , Fungos , Solo , Solo/química , Conservação dos Recursos Naturais , Carbono/análise , Microbiologia do Solo , Produtos AgrícolasRESUMO
INTRODUCTION: Frequent climate change-induced drought events are detrimental environmental stresses affecting global crop production and ecosystem health. Several efforts have facilitated crop breeding for resilient varieties to counteract stress. However, progress is hampered due to the complexity of drought tolerance; a greater variety of novel genes are required across varying environments. Tibetan annual wild barley is a unique and precious germplasm that is well adapted to abiotic stress and can provide elite genes for crop improvement in drought tolerance. OBJECTIVES: To identify the genetic basis and unique mechanisms for drought tolerance in Tibetan wild barley. METHODS: Whole genome resequencing and comparative RNA-seq approaches were performed to identify candidate genes associated with drought tolerance via investigating the genetic diversity and transcriptional variation between cultivated and Tibetan wild barley. Bioinformatics, population genetics, and gene silencing were conducted to obtain insights into ecological adaptation in barley and functions of key genes. RESULTS: Over 20 million genetic variants and a total of 15,361 significantly affected genes were identified in our dataset. Combined genomic, transcriptomic, evolutionary, and experimental analyses revealed 26 water deficit resilience-associated genes in the drought-tolerant wild barley XZ5 with unique genetic variants and expression patterns. Functional prediction revealed Tibetan wild barley employs effective regulators to activate various responsive pathways with novel genes, such as Zinc-Induced Facilitator-Like 2 (HvZIFL2) and Peroxidase 11 (HvPOD11), to adapt to water deficit conditions. Gene silencing and drought tolerance evaluation in a natural barley population demonstrated that HvZIFL2 and HvPOD11 positively regulate drought tolerance in barley. CONCLUSION: Our findings reveal functional genes that have been selected across barley's complex history of domestication to thrive in water deficit environments. This will be useful for molecular breeding and provide new insights into drought-tolerance mechanisms in wild relatives of major cereal crops.
Assuntos
Genoma de Planta , Hordeum , Perfilação da Expressão Gênica , Água , Hordeum/genética , Hordeum/crescimento & desenvolvimento , Genótipo , Variação Genética , Evolução Molecular , Secas , Proteínas de Plantas/genéticaRESUMO
Many plants adapted to harsh environments have evolved low seed mass ('light seeds') with specific dispersal strategies, primarily either by wind (anemochory) or water (hydrochory). However, the role of their seed microbiota in their survival, and their seed microbial abundance and structure, remain insufficiently studied. Herein, we studied the light seed microbiome of eight anemochores and two hydrochores (as controls) collected from four provinces in China, using qPCR and metagenomic sequencing targeting both bacteria and fungi. Substantial variations were found for seed endophytic fungi (9.9 × 1010~7.3 × 102 gene copy numbers per seed) and bacteria (1.7 × 1010~8.0 × 106). Seed microbial diversity and structure were mainly driven by the plant genotype (species), with weak influences from their host plant classification level or dispersal mode. Seed microbial composition differences were clear at the microbial phylum level, with dominant proportions (~75%) for Proteobacteria and Ascomycota. The light seeds studied harbored unique microbial signatures, sharing only two Halomonas amplicon sequence variants (ASVs) and two fungal ASVs affiliated to Alternaria and Cladosporium. A genome-level functional profile analysis revealed that seed bacterial microbiota were enriched in amino acid, nucleoside, and nucleotide biosynthesis, while in fungal communities the generation of precursor metabolites and respiration were more highly represented. Together, these novel insights provide a deeper understanding of highly diversified plant-specific light seed microbiota and ecological strategies for plants in harsh environments.
RESUMO
We can increase the stability of our food systems against environmental variability and climate change by following the footsteps of our ancestors and domesticating edible wild plants. Reinforced by recent advances in comparative genomics and gene editing technologies, neodomestication opens possibilities for a rapid generation of new crops. By starting the candidate selection pipeline with climatic parameters, we orient neodomestication efforts to increase food security against climate change. We highlight the fact that the edible species conservation and characterization will be key in this process. Utilization of genetic resources, entrusted to conservationists and researchers by local communities, has to be conducted with highest ethical standards and benefit-sharing in mind.
Assuntos
Mudança Climática , Produtos Agrícolas , Agricultura , Produtos Agrícolas/genética , Edição de Genes , GenômicaRESUMO
Terminal drought stress affects more than half of the areas planted with common bean (Phaseolus vulgaris), the main food legume globally, generating severe yield losses. Phenotyping water deficit responses and water use are central strategies to develop improved terminal drought resilience. The exploration and exploitation of genetic diversity in breeding programs are gaining importance, with a particular interest in related species with great adaptation to biotic and abiotic factors. This is the case with tepary beans (Phaseolus acutifolius), a bean that evolved and was domesticated in arid conditions and is considered well adapted to drought and heat stress. Under greenhouse conditions, using one genotype of tepary beans (resistant to drought) and two of common beans (one resistant and one susceptible to terminal drought), we evaluated phenotypic differences in traits such as water use efficiency (WUE), transpiration efficiency, rate of photosynthesis, photosynthetic efficiency, stomatal density, stomatal index, stomatal size, and the threshold for transpiration decline under well-watered and terminal drought conditions. Our results indicate two different water use strategies in drought-resistant genotypes: one observed in common bean aimed at conserving soil water by closing stomata early, inhibiting stomatal development, and limiting growth; and the other observed in tepary bean, where prolonged stomatal opening and higher carbon fixation, combined with no changes in stomata distribution, lead to higher biomass accumulation. Strategies that contribute to drought adaptation combined with other traits, such as greater mobilization of photoassimilates to the formation of reproductive structures, confer bean drought resistance and are useful targets in breeding programs.
RESUMO
Thelephora ganbajun is a wild edible mushroom highly appreciated throughout China. The microbiomes of some fungal sporocarps have been studied, however, their potential functional roles currently remain uncharacterized. Here, functional gene microarrays (GeoChip 5.0) and amplicon sequencing were employed to define the taxonomic and functional attributes within three micro-niches of T. ganbajun. The diversity and composition of bacterial taxa and their functional genes differed significantly (p < 0.01) among the compartments. Among 31,117 functional genes detected, some were exclusively recorded in one sporocarp compartment: 1,334 genes involved in carbon (mdh) and nitrogen fixation (nifH) in the context; 524 genes influencing carbon (apu) and sulfite reduction (dsrB, dsra) in the hymenophore; and 255 genes involved in sulfur oxidation (soxB and soxC) and polyphosphate degradation (ppx) in the pileipellis. These results shed light on a previously unknown microbiome and functional gene partitioning in sporome compartments of Basidiomycota. This also has great implications for their potential ecological and biogeochemical functions, demonstrating a higher genomic complexity than previously thought.