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1.
Naturwissenschaften ; 109(6): 54, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36326883

RESUMO

Changes in leaf traits in response to plant-plant interactions affect feeding by insect herbivores. However, the effects of such changes on feeding by vertebrate herbivores remain unclear. We examined the effects of interactions of Aster leiophyllus collected in the field (growing with plants of the same species [aggregated] or with plants of different species [solitary]) or grown in pots (with another A. leiophyllus [intraspecific] or with Carex aphanolepis or Thalictrum baicalense [interspecific]) on the concentration of total phenolics in A. leiophyllus leaves and on sika deer (Cervus nippon) grazing preference in Japan. Deer were presented for 30 s with the first A. leiophyllus leaf (from either aggregated plants or solitary plants) and then for 30 s with the second leaf (solitary or aggregated, respectively). All of the deer presented first with a leaf from a solitary plant ate it, but when deer were presented first with a leaf from an aggregated plant, which had a higher concentration of total phenolics, 50% rejected or left it. About a third of the deer that had been presented first with a leaf from an aggregated plant subsequently rejected the leaf of a solitary plant. The leaves in the intraspecific interaction pot treatment had higher total phenolic concentration and were rejected more by deer than the leaves in the interspecific treatments. Plant-plant interactions affected deer preference, which was also influenced by learning. These results should improve our understanding of both plant grazing by deer and environmental management.


Assuntos
Cervos , Herbivoria , Animais , Cervos/fisiologia , Plantas , Insetos/fisiologia , Folhas de Planta/fisiologia
2.
Environ Monit Assess ; 195(1): 128, 2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36402920

RESUMO

Unmanned aerial vehicles (UAVs) equipped with multi-sensors are one of the most innovative technologies for measuring plant health and predicting final yield in field conditions, especially in the water deficit situation in rain-deprived regions. The objective of this investigation was to evaluate the individual plant and canopy-level measurements using UAV imageries in three different genotypes, Suwan4452 (drought-tolerant), Pac339, and S7328 (drought-sensitive) of maize (Zea mays L.) at vegetative and reproductive stages under WW (well-watered) and WD (water deficit) conditions. At the vegetative stage, only CWSI (crop water stress index) of Pac339 and S7328 under WD increased significantly by 1.86- and 1.69-fold over WW, whereas the vegetation indices (EVI2 (Enhanced Vegetation Index 2), OSAVI (Optimized Soil-Adjusted Vegetation Index), GNDVI (Green Normalized Difference Vegetation Index), NDRE (Normalized Difference Red Edge Index), and NDVI (Normalized Difference Vegetation Index)) derived from UAV multi-sensors did not vary. At the reproductive stage, CWSI in drought-sensitive genotype (S7328) under WD increased by 1.92-fold over WW. All the vegetation indices (EVI2, OSAVI, GNDVI, NDRE, and NDVI) of Pac339 and S7328 under WD decreased when compared with those of Suwan4452. NDVI derived from GreenSeeker® handheld and NDVI from UAV data was closely related (R2 = 0.5924). An increase in leaf temperature (Tleaf) and reduction in NDVI of WD stressed maize plants was observed (R2 = 0.5829) leading to yield loss (R2 = 0.5198). In summary, a close correlation was observed between the physiological data of individual plants and vegetation indices of canopy level (collected using a UAV platform) in drought-sensitive genotypes of maize crops under WD conditions, thus indicating its effectiveness in the classification of drought-tolerant genotypes.


Assuntos
Desidratação , Zea mays , Monitoramento Ambiental , Produtos Agrícolas , Folhas de Planta/fisiologia
3.
Nat Commun ; 13(1): 6412, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376294

RESUMO

Animals possess specialized systems, e.g., neuromuscular systems, to sense the environment and then move their bodies quickly in response. Mimosa pudica, the sensitive plant, moves its leaves within seconds in response to external stimuli; e.g., touch or wounding. However, neither the plant-wide signaling network that triggers these rapid movements nor the physiological roles of the movements themselves have been determined. Here by simultaneous recording of cytosolic Ca2+ and electrical signals, we show that rapid changes in Ca2+ coupled with action and variation potentials trigger rapid movements in wounded M. pudica. Furthermore, pharmacological manipulation of cytosolic Ca2+ dynamics and CRISPR-Cas9 genome editing technology revealed that an immotile M. pudica is more vulnerable to attacks by herbivorous insects. Our findings provide evidence that rapid movements based on propagating Ca2+ and electrical signals protect this plant from insect attacks.


Assuntos
Mimosa , Animais , Mimosa/fisiologia , Cálcio , Folhas de Planta/fisiologia , Insetos , Herbivoria
4.
Sci Rep ; 12(1): 19470, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376438

RESUMO

The diurnal variation of photosynthesis, light response curve and CO2 response curve in Epimedium brevicornu Maxim leaves were determined with Li-6400 photosynthesis system to evaluate the photosynthesis of E. brevicornu. Fluorescence of chlorophyll in the leaves were determined with PAM-2500 portable chlorophyll fluorescence apparatus in the study. The results showed that the midday depression of photosynthesis was very obvious in the E. brevicornu leaves. The light compensation point of E. brevicornu leaves was about 15 µmol m-2 s-1. The light saturation point of E. brevicornu leaves was below 800 µmol m-2 s-1, which was lower than the general sunlight intensity at noon in summer. The CO2 saturation point of E. brevicornu leaves was much higher than the content of CO2 in general air. E. brevicornu was a typical shade plant and could survive in very low sunlight. E. brevicornu could not endure strong sunlight and high air temperature. The net photosynthetic rate of E. brevicornu leaves linearly correlated with the content of CO2 in the leaf chamber when the content was below CO2 saturation point. E. brevicornu possessed great potential of photosynthesis.


Assuntos
Epimedium , Dióxido de Carbono , Fluorescência , Fotossíntese/fisiologia , Clorofila , Folhas de Planta/fisiologia
5.
Curr Biol ; 32(19): R1000-R1002, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36220083

RESUMO

The Venus flytrap possesses modified leaves that can snap shut fast enough to catch a fly. A new study identifies the major components of the toolkit that allows the flytrap to fire action potentials, illustrating how different ion channels and transporters are recruited to give rise to this unique plant behavioural response.


Assuntos
Droseraceae , Potenciais de Ação , Folhas de Planta/fisiologia , Fenômenos Fisiológicos Vegetais
6.
PLoS One ; 17(10): e0274118, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36197886

RESUMO

Dry hot wind (DHW) is one of the main agro-meteorological disasters that occur during the grain filling stage of winter wheat in northern China. In this study, three major winter wheat cultivars planted at the Mazhuang experimental station, Xinji city, Hebei Province, including Henong 6119 (HN6119), Gaoyou 5218 (GY5218), and Jimai 325 (JM325), were analyzed. Through natural DHW and artificially simulated DHW experiments, we investigated how the physiological parameters of the three cultivars were affected on the day with DHW and the day before and after DHW occurred. Comparative analysis of the different responses among the physiological parameters of the three cultivars demonstrated that HN6119 experienced less leaf water loss by reducing its stomata conductance and transpiration rate under natural DHW conditions, while GY5218 and JM325 experienced more leaf water loss by increasing their stomata conductance and transpiration rates under natural DHW conditions. The net photosynthetic rate, transpiration rate, and stomata conductance of HN6119 recovered after the DHW conditions, while those of GY5218 and JM325 showed a continuously decreasing trend. The leaf photosynthetic water use efficiency decreased on DHW days because the net photosynthesis rate was reduced for HN6119, but the transpiration rate increased for GY5218 and JM325. HN6119 showed a significant positive correlation between physiological parameters, while GY5218 and JM325 showed a poor correlation after being affected by DHW conditions. The effect of artificial simulation under mild and severe DHW stress on the thousand kernel weight (TKW) of HN6119, GY5218 and JM325 was 0.01%, 3.51%, 3.57% and 0.36%, 8.12%, 8.84%, respectively. HN6119 showed better resistance to DHW, followed by GY5218, and JM325 showed the weakest resistance.


Assuntos
Triticum , Vento , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Estações do Ano , Triticum/genética , Água
7.
Cells ; 11(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36231016

RESUMO

Mangrove ecosystems are vulnerable to rising sea levels as the plants are exposed to high salinity and tidal submergence. The ways in which these plants respond to varying salinities, immersion depths, and levels of light irradiation are poorly studied. To understand photosynthesis in response to salinity and submergence in mangroves acclimated to different tidal elevations, two-year-old seedlings of two native mangrove species, Kandelia obovata and Rhizophora stylosa, were treated at different salinity concentrations (0, 10, and 30 part per thousand, ppt) with and without immersion conditions under fifteen photosynthetic photon flux densities (PPFD µmol photon·m-2·s-1). The photosynthetic capacity and the chlorophyll fluorescence (ChlF) parameters of both species were measured. We found that under different PPFDs, electron transport rate (ETR) induction was much faster than photosynthetic rate (Pn) induction, and Pn was restricted by stomatal conductance (Gs). The Pn of the immersed K. obovata plants increased, indicating that this species is immersed-tolerant, whereas the Pn level of the R. stylosa plants is salt-tolerant with no immersion. All of the plants treated with 30 ppt salinity exhibited lower Pn but higher non-photochemical quenching (NPQ) and heat quenching (D) values, followed by increases in the excess energy and photoprotective effects. Since NPQ or D can be easily measured in the field, these values provide a useful ecological monitoring index that may provide a reference for mangrove restoration, habitat creation, and ecological monitoring.


Assuntos
Rhizophoraceae , Clorofila/farmacologia , Ecossistema , Fotossíntese , Folhas de Planta/fisiologia , Rhizophoraceae/fisiologia , Salinidade
8.
Physiol Plant ; 174(5): e13762, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36281841

RESUMO

Water stress may greatly limit plant functionality and growth. Stomatal closure and consequently reduced transpiration are considered as early and sensitive plant responses to drought and salinity stress. An important consequence of stomatal closure under water stress is the rise of leaf temperature (Tleaf ), yet Tleaf is not only fluctuating with stomatal closure. It is regulated by several plant parameters and environmental factors. Thermal imaging and different stress indices, incorporating actual leaf/crop temperature and reference temperatures, were developed in previous studies toward normalizing for effects unassociated to water stress on Tleaf , aiming at a more efficient water stress assessment. The concept of stress indices has not been extensively studied on the model plant Arabidopsis thaliana. Therefore, the aim of this study was to examine the different indices employed in previous studies in assessing rosette transpiration rate (E) in Arabidopsis plants grown under two different light environments and subjected to salinity. After salinity imposition, E was gravimetrically quantified, and thermal imaging was employed to quantify rosette (Trosette ) and artificial reference temperature (Twet, Tdry ). Trosette and several water stress indices were tested for their relation to E. Among the microclimatic growth conditions tested, RWSI1 ([Trosette - Twet ]/[Tdry - Twet ]) and RWSI2 ([Tdry - Trosette ]/[Tdry - Twet ]) were well linearly-related to E, irrespective of the light environment, while the sole use of either Twet or Tdry in different combinations with Trosette returned less accurate results. This study provides evidence that selected combinations of Trosette , Tdry , and Twet can be utilized to assess E under water stress irrespective of the light environment.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/fisiologia , Estômatos de Plantas/fisiologia , Desidratação , Secas , Folhas de Planta/fisiologia , Plantas , Transpiração Vegetal/fisiologia
9.
Physiol Plant ; 174(5): e13752, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36281842

RESUMO

Genetic manipulation of whole-plant transpiration rate (TR) response to increasing atmospheric vapor pressure deficit (VPD) is a promising approach for crop adaptation to various drought regimes under current and future climates. Genotypes with a non-linear TR response to VPD are expected to achieve yield gains under terminal drought, thanks to a water conservation strategy, while those with a linear response exhibit a consumptive strategy that is more adequate for well-watered or transient-drought environments. In wheat, previous efforts indicated that TR has a genetic basis under naturally fluctuating conditions, but because TR is responsive to variation in temperature, photosynthetically active radiation, and evaporative demand, the genetic basis of its response VPD per se has never been isolated. To address this, we developed a controlled-environment gravimetric phenotyping approach where we imposed VPD regimes independent from other confounding environmental variables. We screened three nested association mapping populations totaling 150 lines, three times over a 3-year period. The resulting dataset, based on phenotyping nearly 1400 plants, enabled constructing 63-point response curves for each genotype, which were subjected to a genome-wide association study. The analysis revealed a hotspot for TR response to VPD on chromosome 5A, with SNPs explaining up to 17% of the phenotypic variance. The key SNPs were found in haploblocks that are enriched in membrane-associated genes, consistent with the hypothesized physiological determinants of the trait. These results indicate a promising potential for identifying new alleles and designing next-gen wheat cultivars that are better adapted to current and future drought regimes.


Assuntos
Estudo de Associação Genômica Ampla , Triticum , Pressão de Vapor , Triticum/genética , Folhas de Planta/fisiologia , Transpiração Vegetal/genética
10.
Int J Mol Sci ; 23(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36293325

RESUMO

Many higher plants possess a physiological organization that is based upon the carbon economy of their parts. While photosynthates are partitioned according to the relative strength of the plant's sink tissues, in many species there is also a very close relationship between partitioning, phyllotaxy and vascular connectivity giving rise to sectorial patterns of allocation. Here, we examined the influence of smoke and certain chemical constituents prevalent in smoke including, catechol, resorcinol and hydroquinone on phloem vascular sectoriality in common sunflower (Helianthis annuus L.), as a model plant for sectoriality. By administering radioactive carbon-11 to a single source leaf as 11CO2, 11C-photosynthate allocation patterns were examined using autoradiography. A 1:200 aqueous dilution of liquid smoke treated soil caused 2.6-fold and 2.5-fold reductions in phloem sectoriality in sink leaves and roots, respectively. Treatment with catechol (1,2-d ihydroxybenzene) or resorcinol (1,3-dihydroxybenzene), polyphenolic constituents that are prevalent in smoke, caused similar reductions in phloem sectoriality in the same targeted sink tissues. However, treatment with hydroquinone (1,4-dihydroxybenzene) had no effect. Finally, the longer-term effects of smoke exposure on plant growth and performance were examined using outdoor potted plants grown over the 2022 season. Plants exposed to liquid smoke treatments of the soil on a weekly basis had larger thicker leaves possessing 35% greater lignin content than untreated control plants. They also had thicker stems although the lignin content was the same as controls. Additionally, plants exposed to treatment produced twice the number of flowers with no difference in their disk floret diameters as untreated controls. Altogether, loss of phloem sectoriality from exposure to liquid smoke in the sunflower model benefited plant performance.


Assuntos
Helianthus , Floema , Hidroquinonas , Dióxido de Carbono , Fumaça , Lignina , Folhas de Planta/fisiologia , Carbono , Solo , Catecóis , Resorcinóis
11.
Nat Plants ; 8(11): 1304-1316, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36303010

RESUMO

The global carbon and water cycles are governed by the coupling of CO2 and water vapour exchanges through the leaves of terrestrial plants, controlled by plant adaptations to balance carbon gains and hydraulic risks. We introduce a trait-based optimality theory that unifies the treatment of stomatal responses and biochemical acclimation of plants to environments changing on multiple timescales. Tested with experimental data from 18 species, our model successfully predicts the simultaneous decline in carbon assimilation rate, stomatal conductance and photosynthetic capacity during progressive soil drought. It also correctly predicts the dependencies of gas exchange on atmospheric vapour pressure deficit, temperature and CO2. Model predictions are also consistent with widely observed empirical patterns, such as the distribution of hydraulic strategies. Our unified theory opens new avenues for reliably modelling the interactive effects of drying soil and rising atmospheric CO2 on global photosynthesis and transpiration.


Assuntos
Dióxido de Carbono , Estômatos de Plantas , Estômatos de Plantas/fisiologia , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Solo , Carbono
12.
Bioinspir Biomim ; 18(1)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36301693

RESUMO

Direct contact of random objects from the open environment to the panel surface of an electronic device may reduce the work efficiency and cause permanent damage. However, there is a possible way to solve this problem, notably by implementing an adaptive structure design inspired by plants. TheMimosa pudicaplant provides several interesting information on its adaptability. Various studies have been conducted on the electrical properties of its organs explaining the phytoactuator and phytosensor cells that function within it. We combined the use of sensors, actuators, and synthetic excitable tissue as the first robot model purposed to mimic the behavior of theM. pudicaplant. The Computer vision method was used to measure leaf angular movement and collected it as plant behavior data based on the mechanical stimulus experiment. The Robot structure has eight arms equipped with sensors, servo motors, and microcontrollers that are operated with two activation system models approach. The first model could imitate the stimulus process received by electronic circuits that generate action potential signals with a maximum voltage of 4.71-5.02 V and a minimum voltage of -5.33 to -3.45 V that propagated from node to node. The second model involves a trained artificial neural network model with a supervised learning pattern that provides 100% accuracy when choosing movement output based on the given combination. This robot imitates theM. pudica's intelligent sensing capabilities and its ability to change the structure shape based on the thygmonasty experiments data which could provide an overview of how plants process information and perform hazard avoidance actions efficiently. Future applications for the technology inspired by the plant's self-defense mechanisms are adaptive intelligent structures that can protect against harmful conditions, particle contamination, and adjusting panel structure to search for desired environmental parameters.


Assuntos
Robótica , Redes Neurais de Computação , Movimento , Folhas de Planta/fisiologia
13.
Int J Mol Sci ; 23(17)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36077233

RESUMO

Bordeaux mixture (Bm) is a copper (Cu)-based pesticide that has been widely used for controlling citrus scab and citrus canker. However, frequent spraying of Bm is toxic to citrus. To our knowledge, few studies are available that discuss how the photosynthetic characteristics and chloroplast ultrastructure of citrus leaves are affected by Cu toxicity induced by excessive Bm. In the study, two-year-old seedlings of Citrus grandis (C. grandis) and Citrus sinensis (C. sinensis), which were precultured in pots, were foliar-sprayed with deionized water (as control) or Bm diluted 500-fold at intervals of 7 days for 6 times (4 times as recommended by the manufacturer) to investigate the leaf Cu absorption, photosynthesis, chloroplast ultrastructure and antioxidant enzymatic activities. Bm foliar-sprayed 6 times on citrus seedlings increased the leaf Cu content, decreased the photosynthetic pigments content and destroyed the chloroplast ultrastructure, which induced leaf chlorosis and photosynthetic inhibition. A lower Cu absorption, a higher light photon-electron transfer efficiency, a relative integrity of chloroplast ultrastructure and a promoted antioxidant protection contributed to a higher photosynthetic activity of C. grandis than C. sinensis under excessive spraying of Bm. The present study provides crucial references for screening and selecting citrus species with a higher tolerance to Cu toxicity induced by excessive Bm.


Assuntos
Citrus , Antioxidantes , Cloroplastos , Citrus/fisiologia , Cobre/toxicidade , Fotossíntese , Folhas de Planta/fisiologia , Plântula/fisiologia
14.
Oecologia ; 200(1-2): 79-87, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36114944

RESUMO

Nitrogen (N) resorption from senescing leaves enables plants to reuse N, making them less dependent on current N uptake from the environment, leading to higher fitness, particularly under low N supply. Species that form a symbiotic association with N2-fixing bacteria have not evolved proficient N resorption, i.e., they retain more N in the senesced leaves than non-N2-fixing species. However, the physiological mechanism underlying the difference is still unknown. Metabolic and structural protein contents in green and senesced leaves, as well as protein degradation during leaf senescence-a critical initial process for subsequent N resorption-were determined in four N2-fixing legumes and in four non-N2-fixers. The metabolic proteins were highly degraded in legumes and to a lesser extent in nonlegumes. Nonetheless, legumes retained more metabolic proteins in their senesced leaves than nonlegumes, because symbiotic N2 fixation improved the metabolic protein content in green leaves. Symbiotic N2 fixation did not change the structural protein content in green leaves. The structural proteins were moderately degraded in nonlegumes, and almost undegraded in legumes, and more structural proteins remained in the senesced leaves of legumes than in those of nonlegumes. The higher metabolic and structural protein contents in the senesced leaves of N2-fixing legumes properly explained the less proficient N resorption. This is an important step in unraveling molecular mechanisms of different N conservation strategies among plant functional types.


Assuntos
Fabaceae , Nitrogênio , Nitrogênio/metabolismo , Fixação de Nitrogênio , Fósforo/metabolismo , Folhas de Planta/fisiologia , Senescência Vegetal , Plantas/metabolismo , Proteólise
15.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2331-2338, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131647

RESUMO

Two factors-two levels experiment (full light and shading, the irradiance in the shading was 30% of the full light; normal water and drought, where soil moisture was maintained at 75%-80% and 40%-45% of field capacity, respectively) was conducted to study the variation of light-induced stomatal dynamics, stomatal traits, whole plant growth and water use under shading and drought for the early succession stage species Betula platyphylla seedlings in the hilly area of the Loess Plateau. Results showed that shading significantly increased lag and response time by 0.8 and 1.8 times during stomatal opening, decreased response speed significantly by 82.2% and 65.0%, and response amplitude by 43.3% and 56.9% during stomatal opening and closing, respectively. Drought significantly reduced response amplitude by 43.9% during stomatal opening and response speed by 33.0% during stomatal closing. The interaction of shading and drought only affected lag time during stomatal opening. The response speed during stomatal closing was significantly positively correlated with stomatal density and stomatal index. There was no significant correlation between other stomatal dynamic parameters and stomatal anatomical structure. Response speed during stomatal closing was positively correlated with whole plant biomass and water consumption, and there was no correlation between stomatal dynamics parameters and water use efficiency. The results showed that the effects of shading and drought on light-induced stomatal dynamics were partly attributed to the alteration of stomata anatomical structure, and that the light-induced stomatal dynamic parameters could partly explain the alterations of B. platyphylla growth under different habitats.


Assuntos
Secas , Plântula , Betula , Folhas de Planta/fisiologia , Estômatos de Plantas/fisiologia , Plântula/fisiologia , Solo , Água
16.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2371-2378, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131652

RESUMO

Understanding the responses of functional trait variation for grassland plants to grazing disturbance is highly helpful to clarify the community assembly mechanism, functional diversity maintenance, plant adaptation and their strategies. We investigated plant functional traits (plant height, root length, leaf area, root area, leaf dry matter content, shoot dry matter content, root dry matter content, specific leaf area, specific root length and root/ shoot ratio) and the responses of their variation characteristics to grazing disturbance in enclosure and grazing grasslands in Horqin Sandy Land. The results showed that the interspecific variation of functional trait was obviously higher than the intraspecific variation in degraded grassland. The relative contribution of interspecific variation to the overall trait variation ranged from 70.2% to 95.1%, while that of intraspecific variation only contributed 4.9% to 29.8%. However, that did not imply the intraspecific variation could be ignored in the community assembly. The interspecific variation in grazing grassland was lower than that in enclosed grassland, while the intraspecific variation increased but the interspecific variation decreased in grazing grassland. Grazing resulted in the decrease of leaf area and leaf dry matter content but the increase of specific root length for pastoral-resistant grasses. However, pastoral-tolerant forbs would improve their dominance in the community by decreasing specific root length and increa-sing leaf area and leaf dry matter content. The traits sensitive to grazing were leaf area, leaf dry matter content, specific root length, and specific leaf area. Leaf traits and root traits were significantly positively correlated within and with each other. Grazing would enhance the synergy of root traits while reduce the synergy of leaf traits. That meant grazing could change the trade-off strategy of functional traits in individual and population levels, and thus affect vegetation structure and function in community level.


Assuntos
Pradaria , Plantas , Fenótipo , Folhas de Planta/fisiologia , Poaceae/fisiologia
17.
Planta ; 256(4): 68, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36053378

RESUMO

MAIN CONCLUSION: The combination of image-based phenotyping with in-depth anatomical analysis allows for a thorough investigation of plant physiological plasticity in acclimation, which is driven by environmental conditions and mediated by anatomical traits. Understanding the ability of plants to respond to fluctuations in environmental conditions is critical to addressing climate change and unlocking the agricultural potential of crops both indoor and in the field. Recent studies have revealed that the degree of eco-physiological acclimation depends on leaf anatomical traits, which show stress-induced alterations during organogenesis. Indeed, it is still a matter of debate whether plant anatomy is the bottleneck for optimal plant physiology or vice versa. Here, we cultivated 'Salanova' lettuces in a phenotyping chamber under two different vapor pressure deficits (VPDs; low, high) and watering levels (well-watered, low-watered); then, plants underwent short-term changes in VPD. We aimed to combine high-throughput phenotyping with leaf anatomical analysis to evaluate their capability in detecting the early stress signals in lettuces and to highlight the different degrees of plants' eco-physiological acclimation to the change in VPD, as influenced by anatomical traits. The results demonstrate that well-watered plants under low VPD developed a morpho-anatomical structure in terms of mesophyll organization, stomatal and vein density, which more efficiently guided the acclimation to sudden changes in environmental conditions and which was not detected by image-based phenotyping alone. Therefore, we emphasized the need to complement high-throughput phenotyping with anatomical trait analysis to unveil crop acclimation mechanisms and predict possible physiological behaviors after sudden environmental fluctuations due to climate changes.


Assuntos
Aclimatação , Alface , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Pressão de Vapor , Água/fisiologia
18.
PLoS One ; 17(9): e0275024, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36137115

RESUMO

Plants respond to environmental stressors, such as an oligotrophic environments, by altering the morphological and physiological functions of their leaves. Sex affects these functions because of the asymmetric cost of reproduction in dioecious plants. We compared the leaf mass per leaf area (LMA), ratio of intercellular air space in leaf mesophyll tissue (mesophyll porosity), palisade thickness, and carbon isotope ratio (δ13C) of leaves of the dioecious shrub Myrica gale based on sex and gradients of soil water chemistry across habitats in the field. The PCA showed that the first three principal components accounted for 84.5% of the variation. PC1 to PC3 were associated with the origin of soil water, nitrogen status of habitats, and sea-salt contributions, respectively. LMA varied from 5.22 to 7.13 µg/cm2, and it was positively related to PC2 and negatively related to PC3, but not to PC1 or sex, suggesting that LMA was low under poor nitrogen conditions and varied with salinity. Mesophyll porosity values were over 50% for all habitats. Mesophyll porosity was positively affected by PC3 and smaller in females than in males. This suggests that M. gale exhibits differences in mesophyll anatomy according to sex. Palisade thickness ranged from 0.466 to 0.559 mm/mm. The leaves of females had thinner palisade layers per mesophyll layer than those of males; however, the habitat did not affect the thickness of the palisade layer per mesophyll layer. The δ13C values of leaves varied from -32.14 to -30.51 ‰. We found that δ13C values were positively related to PC2 but not to PC1, PC3, and sex. Under poor nitrogen conditions, the δ13C of M. gale leaves decreased, suggesting that nutrient deficiency would decrease more under the long-term averaged ratio of photosynthesis than stomatal conductance, leading to low water use efficiency.


Assuntos
Myrica , Isótopos de Carbono , Células do Mesofilo , Nitrogênio , Fotossíntese , Folhas de Planta/fisiologia , Plantas , Solo , Água
19.
Photosynth Res ; 154(1): 41-55, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36057003

RESUMO

Trees regenerating in the understory respond to increased availability of light caused by gap formation by undergoing a range of morphological and physiological adjustments. These adjustments include the production of thick, sun-type leaves containing thicker mesophyll and longer palisade cells than in shade-type leaves. We asked whether in the shade-regenerating tree Acer pseudoplatanus, the increase in leaf thickness and expansion of leaf tissues are possible also in leaves that are already fully formed, a response reported so far only for a handful of species. We acclimated potted seedlings to eight levels (from 1 to 100%) of solar irradiance and, in late summer, transferred a subset of them to full sunlight. Within 30 days, the pre-shaded leaves increased leaf mass per area and became thicker mostly due to the elongation of palisade cells, except for the most shaded individuals which suffered irreversible photo-oxidative damage. This anatomical acclimation was accompanied by a transient decline in photosynthetic efficiency of PSII (Fv/FM), the magnitude of which was related to the degree of pre-shading. The Fv/FM recovered substantially within the re-acclimation period. However, leaves of transferred plants were shed earlier in the fall, indicating that the acclimation was not fully effective. These results show that A. pseudoplatanus is one of the few known species in which mature leaves may re-acclimate anatomically to increased irradiance. This may be an important mechanism enhancing utilization of gaps created during the growing season.


Assuntos
Acer , Aclimatação/fisiologia , Acer/anatomia & histologia , Acer/fisiologia , Humanos , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Árvores/fisiologia
20.
Photosynth Res ; 154(2): 143-153, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36087250

RESUMO

Although many photosynthesis related processes are known to be controlled by the circadian system, consequent changes in photosynthetic activities are poorly understood. Photosynthesis was investigated during the daily cycle by chlorophyll fluorescence using a PAM fluorometer in Pulmonaria vallarsae subsp. apennina, an understory herb. A standard test consists of a light induction pretreatment followed by light response curve (LRC). Comparison of the major diagnostic parameters collected during day and night showed a nocturnal drop of photosynthetic responses, more evident in water-limited plants and consisting of: (i) strong reduction of flash-induced fluorescence peaks (FIP), maximum linear electron transport rate (Jmax, ETREM) and effective PSII quantum yield (ΦPSII); (ii) strong enhancement of nonphotochemical quenching (NPQ) and (iii) little or no change in photochemical quenching qP, maximum quantum yield of linear electron transport (Φ), and shape of LRC (θ). A remarkable feature of day/night LRCs at moderate to high irradiance was their linear-parallel course in double-reciprocal plots. Photosynthesis was also monitored in plants subjected to 2-3 days of continuous darkness ("long night"). In such conditions, plants exhibited high but declining peaks of photosynthetic activity during subjective days and a low, constant value with elevated NPQ during subjective night tests. The photosynthetic parameters recorded in subjective days in artificial darkness resembled those under natural day conditions. On the basis of the evidence, we suggest a circadian component and a biochemical feedback inhibition to explain the night depression of photosynthesis in P. vallarsae.


Assuntos
Clorofila , Pulmonaria , Clorofila/fisiologia , Pulmonaria/metabolismo , Luz , Fotossíntese/fisiologia , Transporte de Elétrons/fisiologia , Fluorescência , Plantas/metabolismo , Folhas de Planta/fisiologia , Complexo de Proteína do Fotossistema II/metabolismo
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