Plant Biology最新文献

Little is known about the functional role of silicon (Si) in metal-hyperaccumulating plant species, such as Arabidopsis halleri. We investigated the responses of A. halleri from two accessions, Bestwig (Best) and Langelsheim (Lan), to Si supplementation and insect infestation in two controlled full-factorial experiments. Plants were grown in soil either unsupplemented (-Si) or supplemented (+Si) with Si. Some of these plants were kept either uninfested or infested by larvae of the leaf beetle Phaedon cochleariae. Shoot chemical and mechanical traits and plant resistance against the larvae were quantified. Detached leaves from the remaining plants were used to examine whether trichome density and leaf area consumed by larvae were influenced by the accession and/or Si. We found that Si supplementation, but not insect infestation or their interaction, led to twice as high concentrations of shoot Si in +Si in comparison to -Si plants. Insect relative growth rate was not impacted by Si, but by accession, namely lower when larvae fed on Lan than on Best plants. Likewise, leaf area consumed by larvae was consistently lower in the former accession. The density of trichomes was twice as high in plants of the Lan than the Best accession. Uninfested +Si plants contained the highest C/N in both accessions. The composition of glucosinolates differed between accessions, with some glucosinolates being induced by Si, insect infestation or both in the Best plants only. Our findings highlight distinct (induced) defence strategies within A. halleri plants, which may indicate different local adaptations of the source populations.

Cyphomandra betacea, a valuable understory crop in southwestern China, exhibits high sensitivity to water availability. Under global climate change with increasingly erratic precipitation, understanding how Cyphomandra betacea, seedlings respond to rainfall variations is crucial for sustaining this distinctive industry. Through controlled experiments, this work systematically investigates how different rainfall patterns affect seedling growth and physiology, providing a theoretical basis for science-based management under future climate scenarios. Seedlings were subjected to a four-month simulated rainfall experiment with two rainfall intervals (T: 3-day; T₊: 6-day) and three rainfall amounts (W: control; W₊: +40%; W_-: -40%). Biomass, non-structural carbohydrates (NSC), and carbon, nitrogen, phosphorus stoichiometric characteristics were analysed. Seedling growth is more sensitive to variations in rainfall amount, and appropriate increases in rainfall can promote seedling growth and development. Under changes in rainfall patterns, seedlings prioritize the storage of NSC in stems, followed by leaves, with the lowest allocation to roots. Nitrogen content within organs is pivotal for the composition of NSC and can regulate the sugar-starch conversion process. The July W₊T treatment resulted in optimal performance for the majority of growth indicators and demonstrated the highest nutrient accumulation efficiency. We identified a stem-preferential carbon allocation strategy and systemic N limitation, offering key insights for conservation and cultivation under changing climates.

Leaf anatomy is a key factor determining plant ecology. Cell size and number are related to leaf size in tracheophytes, but this has been little studied in bryophytes, which never reach large leaf sizes. We studied the main anatomical factors determining leaf size in mosses, and how this is related to their ecology. We measured cell and leaf dimensions in 287 moss species, as well as cell density, cell wall thickness and midrib length. These measurements were contrasted against different traits, highlighting growth form and genome size, and correlations among traits. Moss leaf size was positively correlated with cell size but negatively correlated with cell density. The longest moss leaves were always supported by midribs reaching or surpassing the leaf apex. Genome size was positively correlated with cell and, especially, leaf size. All these relationships were stronger in acrocarpous mosses. Leaf size in mosses is limited by the mechanical support provided by cell turgor and the midrib. Both mechanical support and effect of genome size were more important in acrocarpous mosses. Our findings suggest anatomy as a key linking factor between genome size and plant ecology.

The continuous fragmentation of tropical forests is a major threat to biodiversity and ecosystem functioning. This process creates extensive forest edges, alters microclimates, and promotes shifts in species composition. Functional traits are key to understanding how species respond to these disturbances and to predicting future vegetation dynamics. This study investigates the ecological strategies of species located at the edges and interiors of forest fragments in the Eastern Amazon. We sampled abundant tree species in seven forest fragments distributed across three municipalities in Pará, Brazil. We analysed 16 morphological and anatomical traits related to leaf economics and xylem function. Comparisons were made between edge and interior environments, and traits were correlated with edaphic variables. Species at forest edges had traits associated with hydraulic efficiency, including higher hydraulic conductivity and a greater fiber fraction. In contrast, interior species displayed a range of strategies, from resource-acquisitive to conservative. We found evidence of a decoupling between leaf and wood trait axes, with wood traits varying independently from leaf traits. Soil conditions influenced trait patterns only at fragment edges. Our study enhances understanding of the mechanisms regulating species survival, as evidenced by the different strategies adopted by plants in the interior and at the edges of forest fragments, reflecting contrasting responses to resource availability. These findings also provide support for conservation and forest management strategies and contribute to policy development aimed at mitigating the impacts of fragmentation on Amazonian biodiversity.

Non-structural carbohydrates (NSC), including soluble sugars (SS) and starch (ST), are vital for plant metabolism and stress resilience. However, how the allocation of NSC and their components varies diurnally between C3 trees and shrubs in arid regions, and their respective roles in drought response, has received limited attention. This study examines the diurnal dynamics of NSC in leaves of woody species to elucidate growth-form-specific carbon storage strategies. In August 2023, we measured SS and ST concentrations in leaves of 16 C3 common species (11 trees, 5 shrubs) in Xinjiang, comparing daytime and nighttime levels. We used a two-way ANOVA to assess the effects of life form (tree/shrub) and time (day/night) on NSC, SS, ST, and SS:ST. Trees had significantly higher NSC and SS concentrations than shrubs. Life form and time jointly influenced NSC, ST, and SS:ST ratios, while SS concentration varied only with life form. Starch accumulates during the day and decreases at night, indicating it is a temporary carbon reserve that is converted to sugars for nighttime metabolism. The findings highlight divergent carbon allocation strategies between the studied C3 trees and shrubs, with trees maintaining higher NSC pools. Diurnal starch turnover underscores its importance in balancing carbon supply under arid conditions. These insights advance our understanding of growth-form-specific adaptations in carbon allocation within water-limited ecosystems.

Space is considered one of the harshest environments for living organisms, where ionizing radiation poses a significant threat to biological systems. Although plants exhibit higher resistance to radiation than animals, their photosynthetic machinery remains highly vulnerable. Given the role of plants in Controlled Ecological Life Support Systems (CELSSs), understanding how environment influences plant performance is critical for space missions. This study investigated the combined effects of X-ray irradiation (0.3, 10, or 20 Gy) and light quality (white, red, or red-blue LEDs) on young Vigna radiata L. plants. To assess plant potential acclimation strategies to radiation, we evaluated key functional traits, focusing on growth and photosynthetic performance. Specifically, we quantified in vivo chlorophyll fluorescence, photosynthetic pigments (chlorophylls, carotenoids), and expression of two major photosynthetic proteins: D1 (PSII core) and Rubisco. To our knowledge, no previous studies have explored how specific light wavelengths modulate plant responses to ionizing radiation during early development stages. Our results showed that red light enhances biomass allocation to shoots, promotes pigment accumulation, specifically at 0.3 and 10 Gy, and maintains higher photochemical efficiency and protein expression even at the highest radiation dose, compared to other light wavelengths. Maintaining an appropriate light environment during initial phases of growth enhances photosynthetic performance, reducing the harmful effects of X-rays, thus enabling plants to fulfil their ecological role in CELSSs.

Caves present unique ecological conditions that influence the distribution and adaptation of species, yet studies on cave-associated vegetation remain limited. This study investigated how cave conditions affect the functional traits of Miconia sellowiana Naudin (Melastomataceae), comparing individuals from the cave interior with those from the adjacent understory. Our objective was to understand how these environments influence the species' morpho-functional characteristics and ecological relevance, aiming to identify physiological responses to the constraints of each habitat. Based on this, we hypothesize that caves act as distinct environmental filters compared to the understory, selecting for unique morphological and physiological variations. Leaf morpho-functional traits were evaluated, including macroscopic dimensions (length, width, and leaf area) and microscopic characteristics, such as the anatomy of the central vein, mesophyll, and epidermis. Samples were fixed, processed for histological sections, and analysed by optical and electron microscopy. Statistical analysis included PCA to identify morpho-functional patterns and Student's t-tests/Wilcoxon tests to compare variables between habitats. Cave individuals had thinner leaves, with fewer layers of photosynthetic parenchyma, smaller relative phloem area in the central vein, lower stomatal density, and reduced leaf area and length compared to understory individuals. Low light availability, high humidity, shallow soils, and nutrient scarcity in caves likely limit the development of thicker leaves and affect stomatal density, vascular tissue, and leaf size. These results suggest that cave environments drive morpho-functional and physiological variations in surrounding plants. This study fills gaps in the literature and highlights ecological mechanisms that sustain life in subterranean ecosystems.

The bud bank of perennial grasses is a key aspect of their reproduction and longevity in frequently burned ecosystems. We investigated how fire intensity and time since fire affected fire-stimulated flowering and bud activity of wiregrass (Aristida beyrichiana), a foundational bunchgrass in south-eastern US pine savannas. We manipulated fuels and monitored fire temperatures in plants during an experimental fire. We tested effects of plant size and fire intensity on flowering stem production and proportions of active and dead buds. We compared active, dead and total buds from plants in the experimental burn with those in stands burned one and 2 years ago, and described the species' bud morphology and anatomy. The duration above 60 °C had a marginally significant negative effect on the number of flowering stems per plant. This effect was less than the significant positive correlation of flowering stem number with plant size. Fire intensity did not affect the proportions of dead and active buds 5 months after fire. There were significant differences in proportions of active, dead and dormant buds 1 year after fire, and the total number of buds decreased with time since fire. Plants had an average of one bud per tiller, and mean bud depth was 3 cm. Perennial bud banks are a substantial source of regenerative biomass for plants in fire-prone savannas. For fire-stimulated flowering species, frequent fires are likely important for maintaining large bud banks that supply both vegetative and flowering structures. A focus on belowground structures should shed light on long-term ecosystem dynamics in fire-prone ecosystems.

Plants are multicellular organisms composed of diverse cell types, each with its own distinct mRNA, protein and metabolite profile. In addition, each cell type exhibits developmental gradients that require fine-tuned balancing with neighbouring cells in terms of cell geometry and chromatin status. These factors highlight the need for precise knowledge of gene expression and chromatin dynamics during stress responses at the single-cell level in planta, linked to cell position and fate. In this viewpoint, we discuss the importance of spatial cell biology in situ methods in modern plant research and briefly compare it with the methods currently available for studying single-cell resolution.