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1.
Physiol Plant ; 176(5): e14541, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39293994

RESUMO

The main aim of this work was to better understand how the low temperature signal from the leaves may affect the stress responses in the roots, and how the light conditions modify certain stress acclimation processes in rice plants. Rice plants grown at 27°C were exposed to low temperatures (12°C) with different light intensities, and in the case of some groups of plants, only the leaves received the cold, while the roots remained at control temperature. RNA sequencing focusing on the roots of plants grown under normal growth light conditions found 525 differentially expressed genes in different comparisons. Exposure to low temperature led to more down-regulated than up-regulated genes. Comparison between roots of the leaf-stressed plants and whole cold-treated or control plants revealed that nitrogen metabolism and nitric oxide-related signalling, as well as the phenylpropanoid-related processes, were specifically affected. Real-time PCR results focusing on the COLD1 and polyamine oxidase genes, as well as metabolomics targeting hormonal changes and phenolic compounds also showed that not only cold exposure of the leaves, either alone or together with the roots, but also the light conditions may influence certain stress responses in the roots of rice plants.


Assuntos
Regulação da Expressão Gênica de Plantas , Luz , Oryza , Raízes de Plantas , Brotos de Planta , Transdução de Sinais , Estresse Fisiológico , Oryza/genética , Oryza/efeitos da radiação , Oryza/fisiologia , Oryza/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/efeitos da radiação , Raízes de Plantas/fisiologia , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Transdução de Sinais/efeitos da radiação , Estresse Fisiológico/genética , Brotos de Planta/efeitos da radiação , Brotos de Planta/genética , Brotos de Planta/fisiologia , Brotos de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Temperatura Baixa , Temperatura , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
Plant Sci ; 348: 112234, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39216696

RESUMO

Plant architecture is an important agronomic trait to determine the biomass and sward structure of forage grass. The IGT family plays a pivotal role in plant gravitropism, encompassing both the gravitropic response and the modulation of plant architecture. We have previously shown that LjLAZY3, one of the IGT genes, plays a distinct role in root gravitropism in L. japonicus. However, the function of LAZY proteins on shoot gravitropism in this species is poorly understood. In this study, we identified nine IGT genes in the L. japonicus genome, which have been categorized into four clades based on the phylogenetic relationships of IGT proteins from 18 legumes: LAZY1, NGR (NEGATIVE GRAVITROPIC RESPONSE OF ROOTS), IGT-LIKE, and TAC1. We found that LAZY genes in the first three clades have demonstrated distinct role for modulating plant gravitropism in L. japonicus with specific impacts as follows. Mutation of the LAZY1 gene, LjLAZY1, defected the gravitropic response of hypocotyl without impacting the main stem's branch angle. In contrast, the overexpression of the NGR gene, LjLAZY3, substantially modulated the shoot's gravitropism, leading to narrower lateral branch angles. Additionally, it enhanced the shoots' gravitropic response. The overexpression of another NGR gene, LjLAZY4, specifically reduced the main stem's branch angle and decreased plant stature without affecting the shoot gravitropic response. The phenotype of IGT-LIKE gene LjLAZY2 overexpression is identical to that of LjLAZY4. While overexpression of the IGT-LIKE gene LjLAZY5 did not induce any observable changes in branch angle, plant height, or gravitropic response. Furthermore, the LjLAZYs were selectively interacted with different BRXL and RLD proteins, which should the important factor to determine their different functions in controlling organ architecture in L. japonicus. Our results deepen understanding of the LjLAZY family and its potential for plant architecture improvement in L. japonicus.


Assuntos
Gravitropismo , Lotus , Brotos de Planta , Gravitropismo/genética , Gravitropismo/fisiologia , Brotos de Planta/genética , Brotos de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Lotus/genética , Lotus/fisiologia , Lotus/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Filogenia , Genes de Plantas , Regulação da Expressão Gênica de Plantas
3.
Plant J ; 120(2): 578-597, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39215624

RESUMO

De novo shoot apical meristem (SAM) organogenesis during regeneration in tissue culture has been investigated for several decades, but the precise mechanisms governing early-stage cell fate specification remain elusive. In contrast to SAM establishment during embryogenesis, in vitro SAM formation occurs without positional cues and is characterized by autonomous initiation of cellular patterning. Here, we report on the initial stages of SAM organogenesis and on the molecular mechanisms that orchestrate gene patterning to establish SAM homeostasis. We found that SAM organogenesis in tobacco calli starts with protuberance formation followed by the formation of an intact L1 layer covering the nascent protuberance. We also exposed a complex interdependent relationship between L1 and WUS expression and revealed that any disruption in this interplay compromises shoot formation. Silencing WUS in nascent protuberances prevented L1 formation and caused the disorganization of the outer cell layers exhibiting both anticlinal and periclinal divisions, suggesting WUS plays a critical role in the proper establishment and organization of L1 during SAM organogenesis. We further discovered that silencing TONNEAU1 prevents the exclusive occurrence of anticlinal divisions in the outermost layer of the protuberances and suppresses the acquisition of L1 cellular identity and L1 formation, ultimately impeding SAM formation and regeneration. This study provides a novel molecular framework for the characterization of a WUS/L1 interplay that mediates SAM formation during regeneration.


Assuntos
Regulação da Expressão Gênica de Plantas , Meristema , Nicotiana , Proteínas de Plantas , Regeneração , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/fisiologia , Nicotiana/genética , Nicotiana/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regeneração/fisiologia , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Organogênese Vegetal/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo
4.
Sci Rep ; 14(1): 18222, 2024 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-39107370

RESUMO

A plant's structure is the result of constant adaptation and evolution to the surrounding environment. From this perspective, our goal is to investigate the mass and radius distribution of a particular plant organ, namely the searcher shoot, by providing a Reinforcement Learning (RL) environment, that we call Searcher-Shoot, which considers the mechanics due to the mass of the shoot and leaves. We uphold the hypothesis that plants maximize their length, avoiding a maximal stress threshold. To do this, we explore whether the mass distribution along the stem is efficient, formulating a Markov Decision Process. By exploiting this strategy, we are able to mimic and thus study the plant's behavior, finding that shoots decrease their diameters smoothly, resulting in an efficient distribution of the mass. The strong accordance between our results and the experimental data allows us to remark on the strength of our approach in the analysis of biological systems traits.


Assuntos
Reforço Psicológico , Brotos de Planta/fisiologia , Folhas de Planta/fisiologia , Modelos Biológicos , Cadeias de Markov , Aprendizagem/fisiologia , Fenômenos Fisiológicos Vegetais
5.
Braz J Biol ; 84: e284231, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39140506

RESUMO

Date palm (Phoenix dactylifera( cv. Medjool is a significant plant, grown in Jordan. In vitro propagation gives operative resources for the significant propagation of date palms. Maximum callus induction was achieved from MS media supplemented with benzyl amino purine (BA) and naphthalene acetic acid (NAA). The highest plant regeneration was recorded on MS medium supplemented with dichlorophenoxyacetic acid (2,4-D) at 3.0 mg/L, and BA at 2.0 mg/L. A significant positive impact on shoot formation was recorded on MS medium supplemented with 1.0 mg/L BA with 0.5 to 1.5 mg/L NAA in both liquid and solid MS medium. To maintain survival and regrowth capacity, sucrose could be used for medium-term conservation at lower concentrations (0.1 - 0.2 M). In addition, sorbitol might be used at 0.1 M to maintain the quality of explants. The vitrification technique for long-term preservation was experimented. Embryogenic callus was used as explants for conservation. The survival as well as regrowth percentages of non-cryopreserved and cryopreserved tissue cultures were affected by their duration of treatment with the vitrification solution plant vitrification solution 2 (PVS2) and modified plant vitrification solution 2 (MPVS2). Results showed that using PVS2 for 60 minutes for cryopreserved calli was more effective than other treatments. After storage in liquid nitrogen, the highest survival rate (65%) and regrowth rate (40%) were achieved.


Assuntos
Phoeniceae , Brotos de Planta , Regeneração , Phoeniceae/fisiologia , Phoeniceae/efeitos dos fármacos , Regeneração/fisiologia , Regeneração/efeitos dos fármacos , Brotos de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Meios de Cultura , Reguladores de Crescimento de Plantas/farmacologia , Criopreservação , Técnicas de Cultura de Tecidos
6.
Physiol Plant ; 176(4): e14477, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39134461

RESUMO

In Mediterranean countries, late-sown durum wheat (Triticum turgidum L. subsp. durum) may face waterlogging (WL) at early stages. As mitigation of waterlogging by melatonin (MT) has been poorly explored, we analyzed the effects of exogenous MT foliar application to WL-stressed durum wheat on its ecophysiological performance, growth and biomass production. Late-sown plants of a relatively tolerant cultivar (i.e., Emilio-Lepido) were subjected to two WL durations (i.e., 14 and 35 days of WL; DOW) at tillering, with or without exogenous MT application (i.e., 0 and 100 µM). Prolonged WL reduced shoot biomass (-43%), but the application of MT mitigated this detrimental effect. Waterlogging impaired photosynthesis, reducing leaf CO2 assimilation and chlorophyll content (-61 and - 57%, at 14 and 35 DOW). In control, MT increased the photosynthetic pigments (+48%), whereas it exacerbated the decrease in photosynthesis under both WL conditions (-72%, on average). Conversely, MT reduced WL-induced oxidative damage in both shoots and roots (-25% hydrogen peroxide production), facilitating osmotic adjustments and mitigating oxidative stress. The accumulation of osmotic regulators in MT + WL plants (+140 and + 42%, in shoots and roots at 35 DOW; respectively) and mineral solutes (+140 and + 104%, on average, in shoots and roots at 14 DOW) likely mitigated WL stress, limiting the impact of oxidative stress and promoting biomass accumulation. Our results highlight the potential of MT as a bioactive compound in mitigating the adverse effects of WL on late-sown durum wheat and the importance of the complex interactions between physiological responses and environmental stressors.


Assuntos
Melatonina , Fotossíntese , Triticum , Triticum/fisiologia , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Melatonina/farmacologia , Melatonina/metabolismo , Fotossíntese/efeitos dos fármacos , Água/metabolismo , Biomassa , Folhas de Planta/fisiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Clorofila/metabolismo , Raízes de Plantas/fisiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Região do Mediterrâneo , Estresse Fisiológico
7.
New Phytol ; 244(1): 292-306, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39135384

RESUMO

Spring regrowth in temperate perennials relies on renewal buds, which form a key component in the shoot growth cycle. Still, we possess almost no information on these renewal buds, which is becoming more pressing with the current climate change. Most existing studies concentrated on easy-to-study aboveground buds of woody plants, whose morphology has largely been linked to frost protection. It is not clear to what extent these findings apply also to herbaceous species. We therefore examined protective traits and preformation of winter renewal buds in 379 species of temperate herbs, and tested how these traits are distributed across the phylogeny and related to other bud bank and whole-plant traits. We identified a major gradient from few, large, highly preformed, scale-covered buds associated with larger belowground storage organs deep in the soil, to small, numerous, less preformed, and naked buds near the soil surface. Belowground renewal buds of temperate herbs show several distinct strategies for winter survival and spring regrowth that might affect their response to changing winter and early spring conditions. Renewal bud traits are driven not only by frost protection but also by protection of the apical meristem from mechanical disturbance in the soil.


Assuntos
Filogenia , Estações do Ano , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Biodiversidade , Especificidade da Espécie , Plantas
9.
Methods Mol Biol ; 2827: 35-50, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38985261

RESUMO

Temporary immersion systems (TIS) have been widely recognized as a promising technology for micropropagation of various plant species. The TIS provides a suitable environment for culture and allows intermittent contact of the explant with the culture medium at different immersion frequencies and aeration of the culture in each cycle. The frequency or immersion is one of the most critical parameters for the efficiency of these systems. The design, media volume, and container capacity substantially improve cultivation efficiency. Different TIS have been developed and successfully applied to micropropagation in various in vitro systems, such as sprout proliferation, microcuttings, and somatic embryos. TIS increases multiplication and conversion rates to plants and a better response during the ex vitro acclimatization phase. This article covers the use of different immersion systems and their applications in plant biotechnology, particularly in plant tissue culture, as well as its use in the massive propagation of plants of agroeconomic interest.


Assuntos
Aclimatação , Desenvolvimento Vegetal , Meios de Cultura/química , Técnicas de Cultura de Tecidos/métodos , Técnicas de Cultura de Tecidos/instrumentação , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Plantas , Imersão , Técnicas de Embriogênese Somática de Plantas/métodos
10.
Tree Physiol ; 44(8)2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39030692

RESUMO

We tested an approach to estimate daily canopy net photosynthesis, A, based on estimates of transpiration, E, using measurements of sap flow and water-use efficiency, ω, by measuring δ13C in CO2 respired from shoots in the canopies of two conifers (Podocarpaceae) native to New Zealand. The trees were planted in adjacent 20-year-old stands with the same soil and environmental conditions. Leaf area index was lower for Dacrycarpus dacrydioides D.Don in Lamb (1.34 m2 m-2) than for Podocarpus totara G.Benn. ex D.Don var. totara (2.01 m2 m-2), but mean (± standard error) stem diameters were the same at 152 ± 21 mm for D. dacrydioides and 154 ± 25 mm for P. totara. Over a 28-day period, daily A (per unit ground area) ranged almost five-fold but there were no significant differences between species (mean 2.73 ± 1.02 gC m-2 day-1). This was attributable to higher daily values of E (2.63 ± 0.83 mm day-1) and lower ω (1.35 ± 0.53 gC kg H2O-1) for D. dacrydioides compared with lower E (1.82 ± 0.72 mm day-1) and higher ω (1.90 ± 0.77 gC kg H2O-1) for P. totara. We attributed this to higher nitrogen availability and nitrogen concentration per unit foliage area, Na, and greater exposure to irradiance in the D. dacrydioides canopy compared with P. totara. Our findings support earlier observations that D. dacrydioides is more adapted to sites with poor drainage. In contrast, the high retention of leaf area and maintaining low rates of transpiration by P. totara, resulting in higher water-use efficiency, is an adaptive response to survival in dry conditions. Our findings show that physiological adjustments for two species adapted to different environments led to similar canopy photosynthesis rates when the trees were grown in the same conditions. We demonstrated consistency between whole-tree and more intensive shoot-scale measurements, confirming that integrated approaches are appropriate for comparative estimates of carbon uptake in stands with different species.


Assuntos
Fotossíntese , Estômatos de Plantas , Água , Fotossíntese/fisiologia , Água/metabolismo , Água/fisiologia , Estômatos de Plantas/fisiologia , Brotos de Planta/fisiologia , Traqueófitas/fisiologia , Traqueófitas/metabolismo , Transpiração Vegetal/fisiologia , Adaptação Fisiológica , Árvores/fisiologia , Folhas de Planta/fisiologia , Folhas de Planta/metabolismo , Nova Zelândia
11.
Ann Bot ; 134(4): 593-602, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-38908006

RESUMO

BACKGROUND AND AIMS: Root system architecture (RSA) plays a key role in plant adaptation to drought, because deep rooting enables better water uptake than shallow rooting under terminal drought. Understanding RSA during early plant development is essential for improving crop yields, because early drought can affect subsequent shoot growth. Herein, we demonstrate that root distribution in the topsoil significantly impacts shoot growth during the early stages of rice (Oryza sativa) development under drought, as assessed through three-dimensional image analysis. METHODS: We used 109 F12 recombinant inbred lines obtained from a cross between shallow-rooting lowland rice and deep-rooting upland rice, representing a population with diverse RSA. We applied a moderate drought during the early development of rice grown in a plant pot (25 cm in height) by stopping irrigation 14 days after sowing. Time-series RSA at 14, 21 and 28 days after sowing was visualized by X-ray computed tomography and, subsequently, compared between drought and well-watered conditions. After this analysis, we investigated drought-avoidant RSA further by testing 20 randomly selected recombinant inbred lines in drought conditions. KEY RESULTS: We inferred the root location that most influences shoot growth using a hierarchical Bayes approach: the root segment depth that impacted shoot growth positively ranged between 1.7 and 3.4 cm in drought conditions and between 0.0 and 1.7 cm in well-watered conditions. Drought-avoidant recombinant inbred lines had a higher root density in the lower layers of the topsoil compared with the others. CONCLUSIONS: Fine classification of soil layers using three-dimensional image analysis revealed that increasing root density in the lower layers of the topsoil, rather than in the subsoil, is advantageous for drought avoidance during the early growth stage of rice.


Assuntos
Secas , Imageamento Tridimensional , Oryza , Raízes de Plantas , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Raízes de Plantas/anatomia & histologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia
12.
J Exp Bot ; 75(16): 5054-5075, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-38753441

RESUMO

Phosphorus nutrition has been known for a long time to influence floral transition in plants, but the underlying mechanism is unclear. Arabidopsis phosphate transporter PHOSPHATE1 (PHO1) plays a critical role in phosphate translocation from roots to shoots, but whether and how it regulates floral transition is unknown. Here, we show that knockout mutation of PHO1 delays flowering under both long- and short-day conditions. The late flowering of pho1 mutants can be partially rescued by Pi supplementation in rosettes or shoot apices. Grafting assay indicates that the late flowering of pho1 mutants is a result of impaired phosphate translocation from roots to shoots. Knockout mutation of SPX1 and SPX2, two negative regulators of the phosphate starvation response, partially rescues the late flowering of pho1 mutants. PHO1 is epistatic to PHO2, a negative regulator of PHO1, in flowering time regulation. Loss of PHO1 represses the expression of some floral activators, including FT encoding florigen, and induces the expression of some floral repressors in shoots. Genetic analyses indicate that at least jasmonic acid signaling is partially responsible for the late flowering of pho1 mutants. In addition, we find that rice PHO1;2, the homolog of PHO1, plays a similar role in floral transition. These results suggest that PHO1 integrates phosphorus nutrition and flowering time, and could be used as a potential target in modulating phosphorus nutrition-mediated flowering time in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Flores , Proteínas de Transporte de Fosfato , Fosfatos , Raízes de Plantas , Brotos de Planta , Arabidopsis/genética , Arabidopsis/fisiologia , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fosfatos/metabolismo , Fosfatos/deficiência , Flores/crescimento & desenvolvimento , Flores/genética , Flores/fisiologia , Flores/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Raízes de Plantas/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Brotos de Planta/genética , Brotos de Planta/fisiologia , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Regulação da Expressão Gênica de Plantas , Mutação , Transporte Biológico
13.
Ann Bot ; 134(2): 351-364, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38702965

RESUMO

BACKGROUND AND AIMS: Desiccation tolerance (DT) is crucial for survival in arid environments, where organisms develop strategies in reproduction, maintenance and defence to cope with water scarcity. Therefore, investigating the relationship between reproduction and DT is essential to understand the ecology and adaptive strategies of species. This study explores the connection between the development of male and female gametangia in the moss Bryum argenteum and the decrease in DT during the progression of phenological phases in gametangia and protonema. METHODS: Samples collected from a dry tropical forest in Brazil were cultivated, cloned and subjected to desiccation. Subsequently, the physiological parameters of shoots and protonemata were analysed. Shoot and protonema regeneration were monitored for 28 d after the physiological analyses. Both phases were subjected to control and desiccation treatments. KEY RESULTS: Significant effects of desiccation and sex on the physiological parameters and regeneration capacity of shoots and protonemata were found. Male shoots generally exhibited lower values of Fv/Fm (quantum efficiency of photosystem II) and ϕPSII (effective quantum yield of photosystem II), while females demonstrated higher values and better recovery after desiccation. Protonemata also showed variation in Fv/Fm over time and with sex, with no significant differences in ϕPSII between them. Desiccated male shoots had higher mortality rates and produced fewer new shoots. For females, the regeneration patterns varied between the desiccation-exposed groups and the control, with decreased shoot production, and some protonemata growing into filaments without forming shoots. CONCLUSION: These findings improve our understanding of the ecological responses of bryophytes to desiccation stress and provide insights into their adaptive strategies in challenging environments, such as the possible rarity of males in dioicous moss populations.


Assuntos
Dessecação , Adaptação Fisiológica/fisiologia , Brotos de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Bryopsida/fisiologia , Reprodução/fisiologia , Brasil
14.
New Phytol ; 244(2): 436-450, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38600040

RESUMO

Integrating traits across above- and belowground organs offers comprehensive insights into plant ecology, but their various functions also increase model complexity. This study aimed to illuminate the interspecific pattern of whole-plant trait correlations through a network lens, including a detailed analysis of the root system. Using a network algorithm that allows individual traits to belong to multiple modules, we characterize interrelations among 19 traits, spanning both shoot and root phenology, architecture, morphology, and tissue properties of 44 species, mostly herbaceous monocots from Northern Ontario wetlands, grown in a common garden. The resulting trait network shows three distinct yet partially overlapping modules. Two major trait modules indicate constraints of plant size and form, and resource economics, respectively. These modules highlight the interdependence between shoot size, root architecture and porosity, and a shoot-root coordination in phenology and dry-matter content. A third module depicts leaf biomechanical adaptations specific to wetland graminoids. All three modules overlap on shoot height, suggesting multifaceted constraints of plant stature. In the network, individual-level traits showed significantly higher centrality than tissue-level traits do, demonstrating a hierarchical trait integration. The presented whole-plant, integrated network suggests that trait covariation is essentially function-driven rather than organ-specific.


Assuntos
Raízes de Plantas , Brotos de Planta , Característica Quantitativa Herdável , Áreas Alagadas , Brotos de Planta/anatomia & histologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Especificidade da Espécie , Fenótipo , Folhas de Planta/anatomia & histologia , Folhas de Planta/fisiologia , Folhas de Planta/crescimento & desenvolvimento
15.
Plant Cell Environ ; 47(6): 2178-2191, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38481026

RESUMO

Understanding crop responses to elevated CO2 is necessary to meet increasing agricultural demands. Crops may not achieve maximum potential yields at high CO2 due to photosynthetic downregulation, often associated with nitrogen limitation. Legumes have been proposed to have an advantage at elevated CO2 due to their ability to exchange carbon for nitrogen. Here, the effects of biological nitrogen fixation (BNF) on the physiological and gene expression responses to elevated CO2 were examined at multiple nitrogen levels by comparing alfalfa mutants incapable of nitrogen fixation to wild-type. Elemental analysis revealed a role for BNF in maintaining shoot carbon/nitrogen (C/N) balance under all nitrogen treatments at elevated CO2, whereas the effect of BNF on biomass was only observed at elevated CO2 and the lowest nitrogen dose. Lower photosynthetic rates at were associated with the imbalance in shoot C/N. Genome-wide transcriptional responses were used to identify carbon and nitrogen metabolism genes underlying the traits. Transcription factors important to C/N signalling were identified from inferred regulatory networks. This work supports the hypothesis that maintenance of C/N homoeostasis at elevated CO2 can be achieved in plants capable of BNF and revealed important regulators in the underlying networks including an alfalfa (Golden2-like) GLK ortholog.


Assuntos
Dióxido de Carbono , Carbono , Medicago sativa , Fixação de Nitrogênio , Nitrogênio , Fotossíntese , Dióxido de Carbono/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo , Medicago sativa/genética , Medicago sativa/fisiologia , Medicago sativa/metabolismo , Medicago sativa/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas , Brotos de Planta/metabolismo , Brotos de Planta/genética , Brotos de Planta/fisiologia
16.
New Phytol ; 242(6): 2440-2452, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38549455

RESUMO

Shoot-level emissions of aerobically produced methane (CH4) may be an overlooked source of tree-derived CH4, but insufficient understanding of the interactions between their environmental and physiological drivers still prevents the reliable upscaling of canopy CH4 fluxes. We utilised a novel automated chamber system to continuously measure CH4 fluxes from the shoots of Pinus sylvestris (Scots pine) saplings under drought to investigate how canopy CH4 fluxes respond to the drought-induced alterations in their physiological processes and to isolate the shoot-level production of CH4 from soil-derived transport and photosynthesis. We found that aerobic CH4 emissions are not affected by the drought-induced stress, changes in physiological processes, or decrease in photosynthesis. Instead, these emissions vary on short temporal scales with environmental drivers such as temperature, suggesting that they result from abiotic degradation of plant compounds. Our study shows that aerobic CH4 emissions from foliage are distinct from photosynthesis-related processes. Thus, instead of photosynthesis rates, it is more reliable to construct regional and global estimates for the aerobic CH4 emission based on regional differences in foliage biomass and climate, also accounting for short-term variations of weather variables such as air temperature and solar radiation.


Assuntos
Secas , Metano , Fotossíntese , Pinus sylvestris , Brotos de Planta , Pinus sylvestris/fisiologia , Pinus sylvestris/metabolismo , Metano/metabolismo , Brotos de Planta/metabolismo , Brotos de Planta/fisiologia , Aerobiose , Temperatura , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Biomassa
17.
Plant Physiol ; 195(2): 1586-1600, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38478430

RESUMO

Leaf angle is a major trait of ideal architecture, which is considered to influence rice (Oryza sativa) cultivation and grain yield. Although a few mutants with altered rice leaf inclination angles have been reported, the underlying molecular mechanism remains unclear. In this study, we showed that a WRKY transcription factor gene, OsWRKY72, was highly expressed in the leaf sheath and lamina joint. Phenotypic analyses showed that oswrky72 mutants had smaller leaf angles than the wild type, while OsWRKY72 overexpression lines exhibited an increased leaf angle. This observation suggests that OsWRKY72 functions as a positive regulator, promoting the enlargement of the leaf angle. Our bioinformatics analysis identified LAZY1 as the downstream gene of OsWRKY72. Electrophoretic mobility shift assays and dual-luciferase analysis revealed that OsWRKY72 directly inhibited LAZY1 by binding to its promoter. Moreover, knocking out OsWRKY72 enhanced shoot gravitropism, which contrasted with the phenotype of lazy1 plants. These results imply that OsWRKY72 regulates the leaf angle through gravitropism by reducing the expression of LAZY1. In addition, OsWRKY72 could directly regulate the expression of other leaf angle-related genes such as FLOWERING LOCUS T-LIKE 12 (OsFTL12) and WALL-ASSOCIATED KINASE 11 (OsWAK11). Our study indicates that OsWRKY72 contributes positively to the expansion of the leaf angle by interfering with shoot gravitropism in rice.


Assuntos
Regulação da Expressão Gênica de Plantas , Gravitropismo , Oryza , Folhas de Planta , Proteínas de Plantas , Brotos de Planta , Fatores de Transcrição , Oryza/genética , Oryza/fisiologia , Oryza/crescimento & desenvolvimento , Gravitropismo/genética , Gravitropismo/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/anatomia & histologia , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Regiões Promotoras Genéticas/genética , Fenótipo
18.
Ann Bot ; 133(7): 969-982, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38366557

RESUMO

BACKGROUND AND AIMS: Plant water status is important for fruit development, because many fleshy fruits contain large amounts of water. However, there is no information on vascular flows of Persea americana 'Hass' avocado. The aims of this research were to explore the impact of drought stress on the water relationships of the 'Hass' avocado plant and its fruit growth. METHODS: Well-watered and water-stressed 'Hass' avocado plants were compared. Over 4 weeks, water flows through the shoot and fruit pedicel were monitored using external sap flow gauges. Fruit diameter was monitored using linear transducers, and stomatal conductance (gs), photosynthesis (A) and leaf and stem water potentials (Ñ°leaf and Ñ°stem) were measured to assess the response of the plants to water supply. KEY RESULTS: In well-watered conditions, the average water inflow to the shoot was 72 g day-1. Fruit water inflow was 2.72 g day-1, but there was water loss of 0.37 g day-1 caused by the outflow (loss back into the tree) through the vascular tissues and 1.06 g day-1 from the fruit skin. Overall, fruit volume increased by 1.4 cm3 day-1. In contrast, water flow into fruit of water-stressed plants decreased to 1.88 g day-1, with the outflow increasing to 0.61 g day-1. As a result, increases in fruit volume were reduced to 0.4 cm3 day-1. The values of A, gs and sap flow to shoots were also reduced during drought conditions. Changes in the hourly time-courses of pedicel sap flow, fruit volume and stem water potential during drought suggest that the stomatal response prevented larger increases in outflow from the fruit. Following re-watering, a substantial recovery in growth rate was observed. CONCLUSIONS: In summary, a reduction in growth of avocado fruit was observed with induced water deficit, but the isohydric stomatal behaviour of the leaves helped to minimize negative changes in water balance. Also, there was substantial recovery after re-watering, hence the short-term water stress did not decrease avocado fruit size. Negative impacts might appear if the drought treatment were prolonged.


Assuntos
Secas , Frutas , Persea , Fotossíntese , Estômatos de Plantas , Água , Persea/fisiologia , Persea/crescimento & desenvolvimento , Estômatos de Plantas/fisiologia , Frutas/fisiologia , Frutas/crescimento & desenvolvimento , Água/fisiologia , Água/metabolismo , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Transpiração Vegetal/fisiologia , Caules de Planta/fisiologia , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/anatomia & histologia , Brotos de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Estresse Fisiológico/fisiologia , Desidratação
19.
Plant Physiol ; 195(2): 1229-1255, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38366651

RESUMO

Trees with weeping shoot architectures are valued for their beauty and are a resource for understanding how plants regulate posture control. The peach (Prunus persica) weeping phenotype, which has elliptical downward arching branches, is caused by a homozygous mutation in the WEEP gene. Little is known about the function of WEEP despite its high conservation throughout Plantae. Here, we present the results of anatomical, biochemical, biomechanical, physiological, and molecular experiments that provide insight into WEEP function. Our data suggest that weeping peach trees do not have defects in branch structure. Rather, transcriptomes from the adaxial (upper) and abaxial (lower) sides of standard and weeping branch shoot tips revealed flipped expression patterns for genes associated with early auxin response, tissue patterning, cell elongation, and tension wood development. This suggests that WEEP promotes polar auxin transport toward the lower side during shoot gravitropic response, leading to cell elongation and tension wood development. In addition, weeping peach trees exhibited steeper root systems and faster lateral root gravitropic response. This suggests that WEEP moderates root gravitropism and is essential to establishing the set-point angle of lateral roots from the gravity vector. Additionally, size exclusion chromatography indicated that WEEP proteins self-oligomerize, like other proteins with sterile alpha motif domains. Collectively, our results from weeping peach provide insight into polar auxin transport mechanisms associated with gravitropism and lateral shoot and root orientation.


Assuntos
Gravitropismo , Ácidos Indolacéticos , Proteínas de Plantas , Prunus persica , Ácidos Indolacéticos/metabolismo , Gravitropismo/fisiologia , Gravitropismo/genética , Prunus persica/genética , Prunus persica/fisiologia , Prunus persica/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Gravitação , Árvores/fisiologia , Árvores/genética
20.
Trends Plant Sci ; 29(7): 718-720, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38418271

RESUMO

Song et al. utilized spatial transcriptomics to study the molecular characteristics of various cells - such as shoot primordia and chlorenchyma cells - in tomato callus during shoot regeneration. This research enhances our knowledge of shoot regeneration and demonstrates the potential of spatial transcriptomics in advancing plant biology.


Assuntos
Regeneração , Transcriptoma , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Brotos de Planta/genética , Brotos de Planta/fisiologia , Regeneração/genética , Regeneração/fisiologia , Solanum lycopersicum/genética , Solanum lycopersicum/fisiologia
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