AoB Plants最新文献

Plants use chemicals to respond to their environments. Despite the impact of competition on plant productivity, few studies consider how plant-plant competition affects phytochemistry; most phytochemistry studies focus on plant-consumer interactions. It therefore remains unclear how plants chemically respond to changes in both competition and consumer pressure. We used ¹H-NMR spectroscopy to characterize the phytochemistry (both primary and secondary metabolites) of a C4 grass (Andropogon gerardi) and a legume (Lespedeza capitata) in a field experiment. Both species were grown with intraspecific or interspecific neighbours (monoculture or 16-species polyculture) with or without a combined fungicide + insecticide treatment (consumers reduced vs. consumers present) in a factorial design. We measured species aboveground biomass, healthy plant cover (NDVI) and phytochemistry in the four treatments to determine whether plants alter their biomass, phytochemistry, or both in response to neighbours and herbivory. Phytochemistry of A. gerardi did not vary with neighbour identity or consumers, in contrast to A. gerardi biomass, which was higher under interspecific competition and when consumers were reduced. Phytochemistry of L. capitata was also unrelated to consumer reduction, though L. capitata had higher NDVI under reduced consumers. However, L. capitata had lower biomass and exhibited phytochemical signs of metabolic stress (lower sugars and higher amino acid production) when grown with interspecific neighbours. Theory and empirical work have focused on coevolution with consumers as driving phytochemical variation, but our results suggest that-at community scales-the competitive environment may be more important than consumer pressure in determining short-term phytochemical responses of some species.

Vessel scaling from tip to base in angiosperms has largely been studied based on vessel diameter. Here, we test if vessel anatomy and transport efficiency in a Fagus sylvatica L. sapling show axial scaling by maintaining a largely proportional ratio of lumen to end-wall resistivity to sap flow with tree height. Vessel diameter (D) of more than 50 000 vessels was measured based on wood sections, while mean vessel length (L_V ) was measured semi-automatically with a Pneumatron for 58 stem segments. Based on tip-to-base variation in D and L_V , we estimated vessel lumen conductivity (K_H ) at the individual vessel level. We also estimated end-wall conductivity (K_W ) based on Darcy's law, integrating pit membrane thickness (T _PM) with scaling of D and total inter-vessel pit membrane area (A_P ) across the sapling. Axial variation in K_W was evaluated against end-wall pressure difference ( $\Delta P$ ). In addition to a tip-to-base increase in D, we found an increase in L_V and A_P , illustrating basipetal vessel lengthening. These patterns were associated with proportional changes in K_W and K_H , which followed a 1:1 relationship with distance to the tip, each contributing to ∼ 50% of the whole-tree conductivity/resistivity. Our findings suggest that vessel dimensions and hydraulic functionality show axial scaling in angiosperm trees, suggesting that anatomy corresponds to the adjustment of hydraulic functionality with plant height. Proportional adjustment of K_W and K_H highlights the key role of vessel dimensions and inter-vessel pits in regulating transport efficiency and safety, potentially maintaining constant resistance per unit leaf area with height growth.

Clonal reproduction is often considered advantageous in stressful environments. While considerable research has explored how clonality supports plant survival in wet and cold conditions, its role in arid and semi-arid conditions remains underexplored. To address this gap, this study examines the distribution and diversity of clonality as a key component of belowground growth form (BGF) along aridity gradients across SW and Central Asia using the species-rich Lamiaceae family as a model. Data were collected from 281 species with a variety of BGFs occurring in a broad range of habitats. Data on BGFs were collected primarily in the field, with additional data from herbarium records and digital databases. BGFs were categorized into hypogeogenous rhizomes, epigeogenous rhizomes, stolons, and non-clonal types. Species distribution data were obtained from regional floras and the Global Biodiversity Information Facility (GBIF) and analysed using precipitation-related bioclimatic variables. Clonal species of the Lamiaceae family, particularly those with hypogeogenous and epigeogenous rhizomes, were more prevalent in extreme environments, both water-limited and moisture-rich, highlighting their adaptation to stressful conditions. They thrived in arid habitats like deserts and semi-deserts as well as wet habitats such as forests or wetlands. Non-clonal species were concentrated in the centre of the gradient, dominating montane steppe shrublands where water availability was moderate and seasonally variable. Clonal plants are not avoiding arid environment. This is particularly noteworthy for species with hypogeogenous rhizomes that have been shown to prefer wet conditions in temperate regions. The exact mechanisms that permit their specialization to wet or dry conditions is to be further studied experimentally. These findings highlight how climate change may differentially affect species based on their BGFs.

Climate change is intensifying droughts across the globe, challenging species to adapt to novel conditions. While plant physiological and phenological responses to drought are well-documented, less is known about how water scarcity affects the evolution of selfing across species ranges. According to the selfing syndrome hypothesis, in environments where selfing confers a fitness advantage, selection should favour floral traits associated with increased selfing relative to outcrossing. We used a field experiment near the northern range edge of the scarlet monkeyflower (Mimulus cardinalis) to test this hypothesis both spatially (among leading-edge, central, and trailing-edge populations), and temporally (between cohorts separated by a period of historic drought). Although populations from different range positions showed genetic differentiation in some floral traits, these differences did not consistently support predictions of the selfing syndrome hypothesis. Contrary to the predictions of reduced investment in floral rewards and increased selfing ability at range edges, the sugar content of nectar was greater and autogamous seed set was smaller in leading-edge than central populations, herkogamy tended to be greater in trailing-edge populations relative to leading-edge and central ones, and nectar volume did not vary predictably among regions. There was no support for the evolution of selfing syndrome from the predrought ancestors to the postdrought descendants. Instead, in leading-edge populations, descendants evolved greater sugar content relative to ancestors, and there were no other differences between ancestors and descendants in any other trait or region. Overall, these findings suggest that mating system evolution in M. cardinalis likely reflects a complex interplay of regional factors including range position, historical adaptation, and local environmental variability, rather than simple stress-induced shifts towards selfing.

Salinity is one of the most devastating abiotic stresses limiting crop productivity. Here, the salinity tolerance level and physiological changes in Echinochloa frumentacea in saline and alkaline soils were estimated by studying root morphology, quantifying ions (Ca²⁺, K⁺, Na⁺, Ca²⁺/Na⁺, and K⁺/Na⁺) in roots, and measuring antioxidant enzyme activities, malondialdehyde (MDA), proline, and soluble sugar contents. Echinochloa frumentacea was tested against four neutral and alkaline salts, NaCl: Na₂SO₄:NaHCO₃:Na₂CO₃ in different proportions at 60, 120, 180, 240, and 300 mmol L^-1 concentrations. Echinochloa frumentacea was evaluated and compared with plant species, which are commonly cultivated in non-saline and alkaline soils i.e. Echinochola crusgalli, Avena sativa, Salicornia europaea, Medicago sativa, and Glycyrrhiza uralensis. The results revealed an increase in root length, diameter, absorption area, fresh, and dry weight at 120 mmol L^-1. However, a gradual decrease in these parameters was observed at higher salt concentrations. In contrast, an increase in superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities, and MDA and proline levels were observed with increasing salt concentration. The roots of E. frumentacea absorbed higher levels of ions than the other five forage plant species. Higher K⁺/Na⁺ and strong root structure in E. frumentacea indicate its better tolerance in saline soil than in alkaline soil. Our results demonstrate that E. frumentacea can tolerate up to 120 mmol L^-1 salt in a saline-alkaline environment and is more suitable for growth in saline soil. In addition, the root system of E. frumentacea can be used to dechlorinate the chloride from soil and reduce its toxic effect on plants. It can also be used as a target species for selection and breeding programs to improve salt tolerance in future studies.

Plant-plant interactions play a crucial role in shaping the growth environment for crops, impacting their productivity and resilience to stress. Interactions between plants have been incorporated into breeding programmes by selecting new target traits that will advance plants' abilities to produce in high densities. The study of plant-plant interactions belowground promises new pathways and traits for crop improvement. This study focuses on the developmental and physiological responses of sorghum (Sorghum bicolor L.) genotypes to neighbouring sorghum plants. In this study, we used two growing methods: (i) a focal plant surrounded by neighbouring plants in the same pot but without shading, and (ii) a focal plant grown either alone or surrounded by neighbours, irrigated with nutrient solution that was passed through pots (leachates) with or without plants. Our results show that the presence of neighbours in the same pot led to reduced dry weight, plant height, and leaf area of the focal plant. In addition, the presence of neighbours reduced stomatal conductance and photosystem II quantum yield. While the response direction was similar across tested genotypes, the magnitude varied. The results were repeated when neighbouring plants were not grown in the same pot, but a nutrient solution was passed through the root systems of other plants into a separate pot containing another plant. Furthermore, we saw a reduction in assimilation rate and stomatal conductance when plants were exposed to either the physical presence of neighbours or leachate. We did not find differences in root architecture in either treatment. These results show that plants change their growth in response to neighbours and that the signal is carried through the liquid phase of the soil. Our findings provide insights into sorghum plants' responses to belowground signalling from neighbouring plants and lay the foundation for future studies enabling increased crop performance under high-density planting conditions.

Eco-evolutionary optimality (EEO) theory predicts that plants maximize resource investment in photosynthetic capacity at the lowest costs of acquiring and using such resources. However, current EEO-based models predict photosynthetic capacity based on climate alone, and omit costs for resource acquisition. To explore the link between leaf-level optimality and plant-level nitrogen acquisition costs across different soil environments, we grew two commonly co-occurring species in a greenhouse under three nutrient fertilization levels in sand and two natural soils with matching nutrient availability to the fertilization levels in sand. At the end of the experiment, we measured the maximum rate of Rubisco carboxylation (V _cmax), δ¹³C-derived leaf-to-air CO₂ partial pressure ratio (c_i /c_a ), and structural carbon costs for nitrogen acquisition. Increasing nutrient availability increased V _cmax (P < .001) and decreased carbon costs for nitrogen acquisition (P < .001), similarly in sand and natural soils (P > .1 for both). Yet, the leaf c_i /c_a remained unchanged across treatments in sand (P = .426) and natural soils (P = .499), consistent with the current EEO-models assumption of climate-dependent optimality. These findings support the general principle that nutrient scarcity increases acquisition costs, while also highlighting a gap in current model formulations that neglect nutrient effects on photosynthetic acclimation.

Fruits are integral to agriculture and receive considerable attention due to their multifold health and nutritional benefits, particularly in the post-pandemic era. The wide range of climatic conditions gives rise to a myriad of fruits grown in different agro-climatic zones; however, fruits grown in tropical and subtropical zones deserve particular attention by virtue of their bountiful nutritional compounds and contribution to substantial growth in the economic sector. Nevertheless, their production is severely affected by their perishable and delicate nature, often limited by various biotic and abiotic factors that result in pre- and post-harvest losses. Scientific advancements have catalyzed efforts to augment the production of tropical and subtropical fruits through genetic and genomic interventions, resulting in the development of numerous advanced genomic resources. These innovations present new opportunities to address key challenges in fruit production, including the mitigation of anti-nutritional factors, improvement of sensory attributes, extension of both pre- and post-harvest shelf-life, chilling sensitivities, and ancillary crop improvements. This review provides a comprehensive synthesis of the genetic and genomic resources available for influential tropical and subtropical fruits, with an emphasis on their potential impact in the context of market acceptability and economic feasibility. These include whole-genome sequencing, which provides insights into domestication and adaptation processes; quantitative traits facilitating the identification of loci associated with desirable traits; functional genomics, enabling biotechnological interventions; the miRNA repertoire for precise trait modulation; and the integration of these resources with CRISPR/Cas9 for tailoring trait modification and recovery. Furthermore, the review highlights the role of web-based platforms that enhance stakeholder engagement and marketing strategies, thereby accelerating the translational potential of research and development in this field. Moreover, the inclusion of single-cell approaches for uncovering cellular heterogeneity, along with multi-omics strategies for dissecting complex traits, is critically discussed. Collectively, these genomic resources are poised to drive transformative changes in the production and utilization of tropical and subtropical fruits, contributing to global nutritional security and sustainable horticultural practices.

Leaf trichomes in plants act as the first line of physical defence against herbivory, in addition to many other reported functions. Although trichomes have been found to vary intraspecifically and can be induced by herbivory, their interactive effects under additional factors, such as plant age and abaxial vs. adaxial leaf surfaces, are less understood. Here, using five common tomato varieties, we explored the effects of these factors and their interactions on trichome type and density. We quantified the densities of Type VI glandular trichomes, non-glandular trichomes, and total trichomes on abaxial and adaxial leaf surfaces, and total leaf trichomes with and without herbivory by Spodoptera exigua at both vegetative and reproductive stages. Further, we also tested whether the time taken to initiate feeding by S. exigua larvae could be influenced by the number of trichomes on the adaxial and abaxial surfaces. The results showed that there is significant variation in trichome density among varieties and leaf surfaces. Also, there were differences in herbivory-induced trichome production, with variable responses across varieties and growth stages. Bioassay results showed that insects took longer to initiate feeding on the abaxial leaf surface than on the adaxial surface, potentially due to the higher density of non-glandular trichomes on the abaxial side. Collectively, we report that the regulation and development of trichomes on the leaf surface of tomatoes is governed by multiple factors, with potential consequences for herbivore feeding, suggesting how physical defences play a significant role in insect-plant interactions.

Papaver somniferum (poppy) is a traditional ingredient in Central and Eastern European cuisine and an important oilseed crop of the region. Since the main threat to stable poppy yield is pathogen infection, a detailed understanding of its defence mechanism is essential. The first robust layer of plant immunity, which plays a crucial role in combating pathogens, is pattern-triggered immunity (PTI). Here, we provide the first comprehensive insights into PTI in poppy. We selected four poppy varieties used in the food industry and investigated their response to various previously described peptide elicitors. Among all tested peptides, flg22 induced the most robust reactive oxygen species (ROS) burst, as well as triggering putative mitogen-activated protein kinase phosphorylation and seedling growth inhibition in all selected cultivars. We identified PsWRKY22 and PsPR2 as candidate marker genes suitable for monitoring poppy PTI responses. The tested poppy cultivars have low levels of salicylic acid. Callose accumulation was triggered by wounding but not by flg22. When studying PTI in plants, wounding is a challenge that needs to be considered, as it can obscure potential PTI responses. Our findings highlight conserved aspects of poppy immunity and the challenges of studying its PTI. The established pipeline facilitates improving our understanding of poppy immunity and has the potential for widespread application in breeding and improving selection for broad-spectrum disease resistance provided by enhanced PTI.