[This corrects the article DOI: 10.1093/aobpla/plae040.].

Members of the grass family Poaceae have adapted to a wide range of habitats and disturbance regimes globally. The cellular structure and arrangements of leaves can help explain how plants survive in different climates, but these traits are rarely measured in grasses. Most studies are focussed on individual species or distantly related species within Poaceae. While this focus can reveal broad adaptations, it is also likely to overlook subtle adaptations within more closely related groups (subfamilies, tribes). This study, therefore, investigated the scaling relationships between leaf size, vein length area (VLA) and vessel size in five genera within the subfamily Pooideae. The scaling exponent of the relationship between leaf area and VLA was -0.46 (±0.21), which is consistent with previous studies. In and , however, minor vein number and leaf length were uncorrelated, whereas in these traits were positively correlated (slope = 0.82 ± 0.8). These findings suggest there are broad-scale and fine-scale variations in leaf hydraulic traits among grasses. Future studies should consider both narrow and broad phylogenetic gradients.

, the causal agent of white mould, is a necrotrophic fungal pathogen responsible for extensive crop loss. Current control options rely heavily on the application of chemical fungicides that are becoming less effective and may lead to the development of fungal resistance. In the current study, we used a foliar application of boron to protect (canola) from infection using whole-plant infection assays. Application of boron to aerial surfaces of the canola plant reduced the number of -forming lesions by 87 % compared to an untreated control. Dual RNA sequencing revealed the effect of boron on both the host plant and fungal pathogen during the infection process. Differential gene expression analysis and gene ontology term enrichment further revealed the mode of action of a foliar boron spray at the mRNA level. A single foliar application of boron primed the plant defence response through the induction of genes associated with systemic acquired resistance while an application of boron followed by infection-induced genes associated with defence response-related cellular signalling cascades. Additionally, in inoculated on boron-treated , we uncovered gene activity in response to salicylic acid breakdown, consistent with salicylic acid-dependent systemic acquired resistance induction within the host plant. Taken together, this study demonstrates that a foliar application of boron results in priming of the plant defence response, likely through systemic acquired resistance, thereby contributing to increased tolerance to infection.

Human population growth constantly requires an increase in the production of food and products from the timber industry. To meet this demand, agriculture and planted forests are advancing over natural areas. In view of this, it is necessary to know the effects of land use for different purposes (grain production, pastures, planted forests, fruit production and among other uses) on the genetic diversity of populations of native species. This knowledge can assist in land use planning as well as in the development of conservation strategies for native species. In this study, we evaluated the effect of land use for agriculture (mainly for cereal production) and planted forests on the genetic diversity of Spreng., a herb native to South America. To achieve our goals, we compared population genetic data obtained with three molecular markers (microsatellites, inter-simple sequence repeat and isoenzymes) with data on land use for agriculture and planted forests from 15 different locations. Our results showed that regardless of the molecular marker used, the greater the use of land for agriculture and planted forests, the lower was the genetic diversity of populations. is a semi-perennial species that needs at least one year to reach its reproductive period, which is prevented in agricultural areas due to the land being turned over or dissected with herbicides every 6 months. In the studied regions, the planted forests are of eucalypt and/or pine, which besides being species with a high production of allelopathic substances, produce strong shading and is a species that inhabits open grassland that needs a high incidence of sunlight for development. The data obtained in our study can assist in the decision-making to use land in order to reconcile the production of supplies for humanity and for the conservation of nature.

Increasingly frequent heat waves threaten the reproduction of flowering plants; compromising the future persistence, adaptive capacity, and dispersal of wild plant populations, and also the yield of fruit-bearing crop plants. Heat damages the development of sensitive floral organs and gametes, which inhibits pollen germination, pollen tube growth, and fertilization. However, the role of heat has not been integrated into the framework of pollen quantity and quality limitation and how heat influences the success of cross and self-pollination. We exposed developing flowers to either controlled temperature (25 °C:20 °C) or extreme heat (35 °C:20 °C) over 72 h. We then hand-pollinated them with either crossed or self-derived pollen from the same temperature treatment to determine the direct and interactive effects of simulated heatwaves on pollen tube growth and resulting seed set. We also collected anthers from virgin flowers to measure heat impacts on pollen production. Under cooler control temperatures pollen tube survival of self-derived pollen was approximately 27% lower than that of crossed pollen. Pollen tube survival in heat-treated cross-pollinated and heat-treated self-pollinated flowers were 71% and 77% lower compared to flowers cross-pollinated at control temperatures. These differences in pollen tube survival rate heat-treated cross-pollinated and heat-treated self-pollinated flowers were insignificant. Furthermore, extreme heat reduced seed set by 87%, regardless of pollen origin, and also reduced pollen production during flower development by approximately 20%. Our results suggest flowers that develop during heatwaves are likely to experience exacerbated pollen quantity and quality limitation driven by changes in pollen production and pollen vigour. Heatwave-induced pollen limitation will likely reduce crop yields in agricultural systems, and depress mating and reproduction in wild plant species, the latter of which may hinder the adaptive capacity of plants to a rapidly changing world.

Many plant species form symbiotic associations with nitrogen-fixing bacteria. Through this symbiosis, plants allocate photosynthate belowground to the bacteria in exchange for nitrogen fixed from the atmosphere. This symbiosis forms an important link between carbon and nitrogen cycles in many ecosystems. However, the economics of this relationship under soil nitrogen availability gradients is not well understood, as plant investment toward symbiotic nitrogen fixation tends to decrease with increasing soil nitrogen availability. Here, we used a manipulation experiment to examine how costs of nitrogen acquisition vary under a factorial combination of soil nitrogen availability and inoculation with in L. (Merr.). We found that inoculation decreased belowground biomass carbon costs to acquire nitrogen and increased total leaf area and total biomass, but these patterns were only observed under low fertilization and were the result of increased plant nitrogen uptake and no change in belowground carbon allocation. These results suggest that symbioses with nitrogen-fixing bacteria reduce carbon costs of nitrogen acquisition by increasing plant nitrogen uptake, but only when soil nitrogen is low, allowing individuals to increase nitrogen allocation to structures that support aboveground growth. This pattern may help explain the prevalence of plants capable of forming these associations in less fertile soils and provides useful insight into understanding the role of nutrient acquisition strategy on plant nitrogen uptake across nitrogen availability gradients.

[This corrects the article DOI: 10.1093/aobpla/plae034.].

Clonality is characterized by the formation of independent individuals of the same genotype that are capable of reproducing and propagating vegetatively. Although clonality is an important mechanism that facilitates the persistence of a population, its extensive use can lead to negative impacts on sexual reproduction due to trade-offs in the investment of resources. Therefore, studies on the sexual reproduction of species that exhibit clonality can provide information about resilience to environmental changes, information about fecundity, the risk of the absence of pollinators and the ability to persist in unfavourable conditions and to successfully occupy new areas. Here, we investigated the role of clonal propagation and sexual reproduction in (Thymelaeaceae), a dioecious species distributed only in Serra dos Carajás. We evaluated the extent of clonality in this species using molecular tools and anatomical analyses of the underground system responsible for developing new ramets. Furthermore, we analysed the sexual system and its contribution to reproductive success through morphometric analyses of floral types and pollination experiments in the field. Overall, we found that clonal propagation plays an important role in maintaining the population of . Specifically, we demonstrated that this species presents functional male and female plants, indicating that is an obligate xenogamous species but has low reproductive success. We also showed that clonal vegetative propagation is the main form of asexual reproduction in this species, with roots responsible for clonal growth. Finally, our results indicated that this species presents an intermediate phalanx-guerrilla clonal architecture. Our study provides the first insights into sexual reproduction and clonal propagation in and can inform management practices, conservation and the restoration of endemic species.

. Using herbarium specimens spanning 133 years and field-collected measurements, we assessed intraspecific trait (leaf structural and stomatal) variability from grass species in the Great Plains of North America. We focused on two widespread, closely related grasses from the tribe Paniceae: subsp. (C) and (C). Thirty-one specimens per taxon were sampled from local herbaria from the years 1887 to 2013 to assess trait responses across time to changes in atmospheric [CO] and growing season precipitation and temperature. In 2021 and 2022, the species were measured from eight grasslands sites to explore how traits vary spatially across natural continental precipitation and temperature gradients. ΔC increased with atmospheric [CO] for . but decreased for . , likely linked to increases in precipitation in the study region over the past century. Notably, this is the first record of decreasing ΔC over time for a C species illustrating C linkages to climate. As atmospheric [CO] increased, C:N increased and δN decreased for both species and %N decreased for . . Across a large precipitation gradient, . leaf traits were more responsive to changes in precipitation than those of . . In contrast, only two traits of . responded to increases in temperature across a gradient: specific leaf area (increase) and leaf dry matter content (decrease). The only shared significant trend between species was increased C:N with precipitation. Our work demonstrates that these closely related grass species with different photosynthetic pathways exhibited various trait responses across temporal and spatial scales, illustrating the key role of scale of inquiry for forecasting leaf trait responses to future environmental change.

Systems-wide understanding of gene expression profile regulating flower colour formation in Planchon is insufficient. In this research, integration analysis of ribonucleic acid (RNA)omics and microRNAome were performed to reveal the molecular mechanism of flower colour formation in three varieties with red, pink and crimson flowers, respectively. Totally, 3129, 5755 and 5295 differentially expressed gene (DEG)s were identified through comparative transcriptome analysis between 'Red variety' and 'Pink variety' (1507 up-regulated and 1622 down-regulated), 'Red variety' and 'Crimson variety' (2148 up-regulated 3607 down-regulated), as well as 'Pink variety' and 'Crimson variety' (2089 up-regulated and 3206 down-regulated), which were involved in processes of 'catalytic activity', 'binding', 'metabolic process' and 'cellular process', as well as pathways of 'metabolic pathways', 'biosynthesis of secondary metabolites', 'plant-pathogen interaction' and 'phenylpropanoid biosynthesis'. A total of 215 miRNAs, containing 153 known miRNAs belonging to 57 families and 62 novel miRNA, were involved in flower colour formation. In particular, 55 miRNAs were significantly differently expressed. Based on miRNA-mRNA regulatory network, ath-miR5658 could affect the synthesis of pelargonidin, cyanidin and delphinidin through downregulating accumulation of anthocyanidin 3-O-glucosyltransferase; ath-miR868-3p could regulate isoflavonoid biosynthesis through downregulating expression of CYP81E1/E7; ath-miR156g regulated the expression of flavonoid 3',5'-hydroxylase; and ath-miR829-5p regulated flavonol synthasein flavonoid biosynthesis process. This research will provide important roles in breeding new varieties with rich flower colour.

By developing and implementing a local temperature control system, such as a root zone, with a high energy efficiency heat source, we can ensure both yield and energy efficiency against extreme temperatures. This system, designed with practicality in mind, has a remarkably positive impact on paprika plants' growth and yield in greenhouse cultivation. In the summer season, paprika plants were grown with no cooling, nutrient solution cooling (NSC) and the combination of NSC and substrate surround cooling (SSC) (NSC + SSC). In the case of SSC, cooled water circulated through the pipe surrounding the substrate to lower the substrate temperature. The cooling system maintains the nutrient solution temperature at 18 °C and the circulating water temperature at the system in the winter season; the paprika plants were grown with no heating (NH), nutrient solution heating (NSH) and the combination of NSH and substrate surround heating (SSH) (NSH + SSH). The heating system maintains the nutrient solution temperature at 25 °C and the circulating water temperature at 30 °C. In the summer, the root fresh and dry weights, stem fresh and dry weights, stem length and node number were increased in the NSC + SSC. In the winter season, the stem fresh and dry weights, leaf area and leaf fresh and dry weights were increased in the NSH + SSH. In both seasons, root-zone temperature control increased the fruit quality and yield. The result indicates that this easy-to-install root-zone temperature control system can be applied to the commercial greenhouse to secure paprika growth and yield in year-round cultivation.

Flavonoids in Musaceae are involved in pigmentation and stress responses, including cold resistance, and are a component of the healthy human diet. Identification and analysis of the sequence and copy number of flavonoid biosynthetic genes are valuable for understanding the nature and diversity of flavonoid evolution in Musaceae species. In this study, we identified 71-80 flavonoid biosynthetic genes in chromosome-scale genome sequence assemblies of Musaceae, including those of , , , , and checking annotations with BLAST and determining the presence of conserved domains. The number of genes increased through segmental duplication and tandem duplication. Orthologues of both structural and regulatory genes in the flavonoid biosynthetic pathway are highly conserved across Musaceae. The flavonoid 3',5'-hydroxylase gene was amplified in Musaceae and ginger compared with grasses (rice, Brachypodium, and sorghum). One group of genes from this gene family amplified near the centromere of chromosome 2 in the  = 11 Musaceae species. Flavonoid biosynthetic genes displayed few consistent responses in the yellow and red bracts of when subjected to low temperatures. The expression levels of (dihydroflavonol reductase) increased while (leucoanthocyanidin reductase) was reduced by half. Overall, the results establish the range of diversity in both sequence and copy number of flavonoid biosynthetic genes during evolution of Musaceae. The combination of allelic variants of genes, changes in their copy numbers, and variation in transcription factors with the modulation of expression under cold treatments and between genotypes with contrasting bract-colours suggests the variation may be exploited in plant breeding programmes, particularly for improvement of stress-resistance in the banana crop.

Measuring seminal root angle is an important aspect of root phenotyping, yet automated methods are lacking. We introduce SeminalRootAngle, a novel open-source automated method that measures seminal root angles from images. To ensure our method is flexible and user-friendly we build on an established corrective annotation training method for image segmentation. We tested SeminalRootAngle on a heterogeneous dataset of 662 spring barley rhizobox images, which presented challenges in terms of image clarity and root obstruction. Validation of our new automated pipeline against manual measurements yielded a Pearson correlation coefficient of 0.71. We also measure inter-annotator agreement, obtaining a Pearson correlation coefficient of 0.68, indicating that our new pipeline provides similar root angle measurement accuracy to manual approaches. We use our new SeminalRootAngle tool to identify single nucleotide polymorphisms (SNPs) significantly associated with angle and length, shedding light on the genetic basis of root architecture.

Cotyledons play an important role in early seedling establishment. However, relative to primary leaves, cotyledons tend to have a different investment-on-return strategy. To detect the potential differences in the mass () versus area () scaling relationships between cotyledons and primary leaves in different light environments, a total of 75 seedlings were sampled at an open site ( = 52; light availability: 74 ± 5 %) and a shaded site ( = 23; light availability: 4.2 ± 1.2 %). Reduced major axis regression protocols were used to fit the versus scaling relationships of primary leaves and cotyledons. The bootstrap percentile method was used to test the significance of the differences in the scaling exponents of versus between the two light environments. The scaling exponents of cotyledons at both two sites, as well as the primary leaves at the shade site, were greater than unity indicating 'diminishing returns', while the scaling exponent of primary leaves at the open site was smaller than unity indicating 'increasing returns'. The data collectively indicated light-dependent shifts in support investments and differences in the function of cotyledons and primary leaves. Average leaf structural traits displayed significant differences between the two light environments in accordance with the premium in enhancing photosynthetic capacity in high light and light interception in low light. Although the trait responses to light availability were similar for primary leaves and cotyledons, primary leaves were more responsive to light availability, indicating lower plasticity of cotyledons in response to light levels. These results advance our understanding of the roles of cotyledons and primary leaves in the life history of seedlings in different forest light environments.

Mosses are distributed all over the world including Antarctica. Although Antarctic mosses show active growth in a short summer season under harsh environments such as low temperature, drought and high levels of UV radiation, survival mechanisms for such multiple environmental stresses of Antarctic mosses have not yet been clarified. In the present study, transcriptome analyses were performed using one of the common mosses grown under an Antarctic field and artificial cultivation conditions. Totally 88 205 contigs were generated by assembly, among which 1377 and 435 genes were significantly up and downregulated, respectively, under Antarctic field conditions compared with artificial cultivation conditions at 15°C. Among the upregulated genes, a number of lipid metabolism-related and oil body formation-related genes were identified. Expression levels of these genes were increased by artificial environmental stress treatments such as low temperature, salt and osmic stress treatments. Consistent with these results, . grown under Antarctic field conditions contained large amounts of fatty acids, especially α-linolenic acid, linolenic acid and arachidonic acid. In addition, proportion of unsaturated fatty acids, which enhance membrane fluidity, to the total fatty acids was also higher in . grown under Antarctic field conditions. Since lipid accumulation and unsaturation of fatty acids are generally important factors for the acquisition of various environmental stress tolerance in plants, these intracellular physiological and metabolic changes may be responsible for the survival of . under Antarctic harsh environments.

Leaf-scale photosynthetic optimization models can quantitatively predict photosynthetic acclimation and have become an important means of improving vegetation and land surface models. Previous models have generally been based on the optimality assumption of maximizing the net photosynthetic assimilation per unit leaf area (i.e. the area-based optimality) while overlooking other optimality assumptions such as maximizing the net photosynthetic assimilation per unit leaf dry mass (i.e. the mass-based optimality). This paper compares the predicted results of photosynthetic acclimation to different environmental conditions between the area-based optimality and the mass-based optimality models. The predictions are then verified using the observational data from the literatures. The mass-based optimality model better predicted photosynthetic acclimation to growth light intensity, air temperature and CO concentration, and captured more variability in photosynthetic traits than the area-based optimality models. The findings suggest that the mass-based optimality approach may be a promising strategy for improving the predictive power and accuracy of optimization models, which have been widely used in various studies related to plant carbon issues.

. The plant growth regulator 6-benzylaminopurine (BAP) is an important component of plant nutrient medium with tendency to accelerate physiological, biochemical and molecular processes in woody plants such as olive. To date, limited knowledge is available on the role of BAP in mediating physiological, biochemical and genetic activities in olives under conditions. To cover this research gap, the current study was conducted with the objective of studying the role of BAP in regulating physiological traits (chlorophyll, CO assimilation), antioxidant enzymes (superoxide dismutase, catalase and peroxidase), metabolic contents (starch, sucrose and flavonoids) and gene expression ( under varying concentrations (0, 0.5, 1.5 and 2.5 mg L) within the provided conditions. The explants obtained from different olive cultivars ('Leccino', 'Gemlik', 'Moraiolo', 'Arbosana') were cultured on olive medium (OM) provided with different BAP concentrations using a two-factorial design, and data were analysed statistically. All traits increased significantly under conditions due to increasing concentrations of BAP; however, this increase was more dramatic at 2.5 mg L and the least dramatic at 0.5 mg L. Moreover, correlation, principal component analysis and heatmap cluster analysis confirmed significant changes in the paired association and expression of traits with changing BAP concentration and type of olive cultivars. Likewise, the expression of all genes varied due to changes in BAP concentration in all cultivars, corresponding to variations in physiological and biochemical traits. Moreover, the spectrographs generated via scanning electron microscopy further indicated the variations in the distribution of elements in olive leaf samples due to varying BAP concentrations. Although all cultivars showed a significant response to varying concentrations of BAP, the response of Arbosana was statistically more significant. In conclusion, the current study proved the dynamic impact of the varying BAP concentrations on regulating the physiological, biochemical, and molecular attributes of olive cultivars.

Climate change models predict increasing precipitation variability in the mid-latitude regions of Earth, generating a need to reduce the negative impacts of these changes on crop production. Despite considerable research on how cover crops support agriculture in a changing climate, understanding is limited of how climate change influences the growth of cover crops. We investigated the early development of two common cover crop species-crimson clover () and rye ()-and hypothesized that growing them in the mixture would ameliorate stress from drought or waterlogging. This hypothesis was tested in a 25-day greenhouse experiment, where the two factors (species number and water stress) were fully crossed in randomized blocks, and plant responses were quantified through survival, growth rate, biomass production and root morphology. Water stress negatively influenced the early growth of these two species in contrasting ways: crimson clover was susceptible to drought while rye performed poorly under waterlogging. Per-plant biomass in rye was always greater in mixture than in monoculture, while per-plant biomass of crimson clover was greater in mixture under drought. Both species grew longer roots in mixture than in monoculture under drought, and total biomass of mixtures did not differ significantly from the more-productive monoculture (rye) in any water condition. In the face of increasingly variable precipitation, growing crimson clover and rye together has potential to ameliorate water stress, a possibility that should be further investigated in field experiments.

Bamboos stand out among other tall plants in being able to generate positive pressure in the xylem at night, pushing water up to the leaves and causing drops to fall from leaf tips as guttation that can amount to a steady nocturnal 'bamboo rain'. The location and mechanism of nocturnal pressure generation in bamboos are unknown, as are the benefits for the plants. We conducted a study on the tall tropical bamboo species (giant timber bamboo) growing outdoors in southern California under full irrigation to determine where in the plant the nocturnal pressure is generated, when it rises in the evening, and when it dissipates in the morning. We hypothesized that the build-up of positive pressure would be triggered by the cessation of transpiration-driven sap flow and that resumption of sap flow in the morning would cause the pressure to dissipate. Nocturnal pressure was observed in mature stems and rhizomes, but never in roots. The pressure was episodic and associated with stem swelling and was usually, but not always, higher in rhizomes and basal stems than in stems at greater height. Time series analyses revealed that dry atmospheric conditions were followed by lower nocturnal pressure and rainfall events by higher stem pressure. Nocturnal pressure was unrelated to sap flow and even was generated for a short time in isolated stem pieces placed in water. We conclude that nocturnal pressure in bamboo is not 'root pressure' but is generated in the pseudo-woody rhizomes and stems. It is unrelated to the presence or absence of sap flow and therefore must be created outside of vessels, such as in phloem, parenchyma, or fibres. It is unlikely to be a drought adaptation and may benefit the plants by maximizing stem water storage for daytime transpiration or by transporting nutrients to the leaves.

Stomatal anatomy and behaviour are key to managing gas exchange fluxes, which require coordination with the plant vascular system to adequately supply leaves with water. Stomatal response times and regulation of water loss are generally understudied in ferns, especially across habits (i.e. epiphytic and terrestrial) and habitats (i.e. wet mesic and dry xeric environments). Our objectives were to (i) determine if hydraulic and anatomical traits that control water use are correlated with their habitats (i.e. xeric, mesic) and habits (i.e. epiphytic, terrestrial) for ferns and lycophytes across taxa, and (ii) explore how those traits and others like average leaf water residence time correlate with stomatal function using a subset of closely related species. Epiphytic species had lower vein densities than terrestrial species, while xeric species had higher vein densities than mesic species. Xeric ferns also had smaller stomata than mesic ferns but had similar stomatal densities. Further, in a subset of mesic and xeric ferns, the xeric ferns had higher maximum stomatal conductance and water content, as well as shorter average stomatal opening responses to light intensity, but stomatal closing times did not differ. Finally, shorter stomatal opening and closing responses were correlated with shorter water residence time. Our study highlights anatomical and physiological differences between ferns and lycophytes, which may partially explain habitat preference based on their optimization of light and water.

[This corrects the article DOI: 10.1093/aobpla/plad022.].