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SUMMARY: Acyl‐acyl carrier protein (ACP) thioesterases (FAT) hydrolyze acyl‐ACP complexes to release FA in plastids, which ultimately affects FA biosynthesis and profiles. Soybean GmFATA1 and GmFATA2 are homoeologous genes encoding oleoyl‐ACP thioesterases whose role in seed oil accumulation and plant growth has not been defined. Using CRISPR/Cas9 gene editing mutation of Gmfata1 or 2 led to reduced leaf FA content and growth defect at the early seedling stage. In contrast, no homozygous double mutants were obtained. Combined this indicates that GmFATA1 and GmFATA2 display overlapping, but not complete functional redundancy. Combined transcriptomic and lipidomic analysis revealed a large number of genes involved in FA synthesis and FA chain elongation are expressed at reduced level in the Gmfata1 mutant, accompanied by a lower triacylglycerol abundance at the early seedling stage. Further analysis showed that the Gmfata1 or 2 mutants had increased composition of the beneficial FA, oleic acid. The growth defect of Gmfata1 could be at least partially attributed to reduced acetyl‐CoA carboxylase activity, reduced abundance of five unsaturated monogalactosyldiacylglycerol lipids, and altered chloroplast morphology. On the other hand, overexpression of GmFATA in soybean led to significant increases in leaf FA content by 5.7%, vegetative growth, and seed yield by 26.9%, and seed FA content by 23.2%. Thus, overexpression of GmFATA is an effective strategy to enhance soybean oil content and yield. Significance Statement: Our results demonstrated that the positive roles of GmFATA1 and GmFATA2 on soybean growth, seed oil accumulation. We propose that overexpression of GmFATA could be an engineering strategy to enhance soybean oil content and yield. In addition, the Gmfata1/2 mutants with increased content of benefit oil oleic acid could be used as germplasm sources in breeding of soybean oil quality. [ABSTRACT FROM AUTHOR]

This article explores the significance of belowground processes in tropical forest restoration and offers recommendations for further understanding these processes. It emphasizes the role of plant-root interactions, soil microbes, and soil properties in driving essential ecosystem services such as erosion control, nutrient cycling, and carbon sequestration. The article highlights the importance of plant-microbe interactions in forest recovery and proposes management strategies for soil stabilization, carbon storage, nutrient cycling, and forest diversity. It also stresses the selection of native mycorrhizal communities and cautions against using non-native soil inoculum. The authors argue that incorporating belowground research into land management strategies can enhance the effectiveness of restoration projects, while also emphasizing the need for collaboration between scientists and restoration practitioners and the consideration of ecological, economic, and social factors in restoration areas. [Extracted from the article]

As global climatic changes increase plant susceptibility to large-scale disturbances such as drought and pathogens, understory responses to these disturbances will become increasingly important to long-term forest dynamics. To better understand understory responses to canopy disturbance, we measured changes in the growth and physiology of the dominant understory shrub, American witch-hazel (Hamamelis virginiana L.), in response to girdling of canopy oaks in a temperate hardwood forest of the northeastern United States. Changes in the growth and physiology of H. virginiana may be important to the regeneration of northeastern temperate forests, as this common shrub largely shapes the microenvironment for seedlings on the forest floor where it occurs. Canopy disturbance by girdling resulted in significant increases in light and soil nitrogen availability. In response to these environmental changes, basal-area growth of H. virginiana increased by an average 334%. This growth increase corresponded to significant increases in foliar nitrogen, respiration, and leaf chlorophyll and carotenoid concentrations. These findings indicate improved environmental conditions and increased growth for this understory shrub following the loss of dominant canopy trees. This study suggests that following large-scale canopy disturbance, H. virginiana and shrubs like it may play an important role in competing for soil N and shading seedlings of regenerating canopy species. Key words: Black Rock Forest, canopy disturbance, foliar chemistry, photosynthesis, respiration. A mesure que les changements climatiques a l'echelle planetaire augmentent la sensibilite des plantes aux perturbations a grande echelle, telles que la secheresse et les agents pathogenes, les reactions du sous-bois face a ces perturbations vont devenir de plus en plus importantes pour la dynamique forestiere a long terme. Dans le but de mieux comprendre les reactions du sous-bois aux perturbations du couvert forestier, nous avons mesure les changements dans la croissance et la physiologie de l'arbuste de sous-bois dominant, l'hamamelis de Virginie (Hamamelis virginiana L.), en reaction a l'annelation des chenes de l'etage dominant dans une foret feuillue temperee du nord-est des Etats-Unis. Les changements dans la croissance et la physiologie de l'hamamelis pourraient avoir des repercussions importantes sur la regeneration des forets temperees du nord-est etant donne l'influence determinante de cet arbuste commun sur le microenvironnement des semis au sol ou il est present. La perturbation du couvert forestier par l'annelation a entraine une augmentation significative de la disponibilite de la lumiere et de l'azote dans le sol. En reaction a ces changements environnementaux, la croissance en surface terriere de l'hamamelis a augmente en moyenne de 334 %. Cette augmentation de croissance correspond a des augmentations significatives de l'azote foliaire, de la respiration et des concentrations de chlorophylle et de carotenoide dans les feuilles. Ces resultats sont un indice de meilleures conditions environnementales et d'une croissance accrue pour cet arbuste de sous-bois a la suite de la perte des arbres de l'etage dominant. Cette etude indique qu'a la suite d'une perturbation a grande echelle du couvert forestier, l'hamamelis et les arbustes semblables pourraient jouer un role important en competitionnant pour l'azote dans le sol et en ombrageant les semis des especes de l'etage dominant qui se regenerent. [Traduit par la Redaction] Mots-cles: foret de Black Rock, perturbation du couvert forestier, chimie foliaire, photosynthese, respiration., Introduction Temperate hardwood forests play an important role in regulating water and nutrients, sequestering carbon (C), and providing habitat for biodiversity. In the United States (US) and southern Canada, many [...]

In order to obtain chitosan (CS) based composite film materials with satisfactory functional properties, CS based antibacterial and antioxidant composite films (CS / nBC / KA/ CUR) containing nanobacterium cellulose ( nBC), curcumin (CUR) and kojic acid (KA) was prepared by mixed solution casting method. The barrier prop- erties, mechanical properties, optical properties, antibacterial activity, and antioxidant activity of different compo- nent composite films were investigated. The results showed that the components of CS / nBC / KA/ CUR composite film interacted with each other mainly by hydrogen bonding and van der Waals force, and the interior of the film showed a relatively enhanced crystallinity. Compared with the other composite films, the water solubility of CS / nBC / KA/ CUR composite films was decreased significantly. The water vapor transmission rate was increased by nearly 24% compared with CS / nBC composite films. The tensile strength was increased by nearly 3 times, and the elongation at break was increased by about 1. 8% compared with CS / nBC / KA composite films. The antibacterial effect against E. coli was increased by about 12. 2% compared with the other composite films, and the ABTS free radical scaven- ging rate was most greatly increased by 35. 2% compared with CS / nBC composite films. Therefore, CS / nBC / KA/ CUR composite films combined the advantages of each components and showed a certain potential value in the de- velopment of active food packaging materials. [ABSTRACT FROM AUTHOR]

Plant vacuoles serve as the primary intracellular compartments for phosphorus (P) storage. The Oryza sativa genome contains three genes that encode SPX (SYG1/ PHO81/ XPR1)‐MFS (Major Facility Superfamily) proteins (OsSPX‐MFS1‐3). The physiological roles of the three transporters under varying P conditions in laboratory and field are not known. To address this knowledge gap, we generated single, double and triple mutants for three OsSPX‐MFS genes. All the mutants except Osspx‐mfs2 display lower vacuolar Pi concentrations and OsSPX‐MFSs overexpression plant display higher Pi accumulation, demonstrating that all OsSPX‐MFSs are vacuolar Pi influx transporters. OsSPX‐MFS3 plays the dominant role based on the phenotypes of single mutants in terms of growth, vacuolar and tissue Pi concentrations. OsSPX‐MFS2 is the weakest and only functions as vacuole Pi sequestration in an Osspx‐mfs1/3 background. The vacuolar Pi sequestration capacity was severely impaired in Osspx‐mfs1/3 and Osspx‐mfs1/2/3, which resulted in increased Pi allocation to aerial organs. High P in the panicle impaired panicle and fertility in Osspx‐mfs1/3 and Osspx‐mfs1/2/3. Osspx‐mfs2 resulted in a more stable yield compared to the wild type under low P in field grown plants. The results suggest that alteration of vacuolar Pi sequestration may be a novel effective strategy to improve rice tolerance to low phosphorus in cropping systems. [ABSTRACT FROM AUTHOR]

Quantifying human impacts on the nitrogen (N) cycle and investigating natural ecosystem N cycling depend on the magnitude of inputs from natural biological nitrogen fixation (BNF). Here, we present two bottom‐up approaches to quantify tree‐based symbiotic BNF based on forest inventory data across the coterminous United States and SE Alaska. For all major N‐fixing tree genera, we quantify BNF inputs using (1) ecosystem N accretion rates (kg N ha−1 yr−1) scaled with spatial data on tree abundance and (2) percent of N derived from fixation (%Ndfa) scaled with tree N demand (from tree growth rates and stoichiometry). We estimate that trees fix 0.30–0.88 Tg N yr−1 across the study area (1.4–3.4 kg N ha−1 yr−1). Tree‐based N fixation displays distinct spatial variation that is dominated by two genera, Robinia (64% of tree‐associated BNF) and Alnus (24%). The third most important genus, Prosopis, accounted for 5%. Compared to published estimates of other N fluxes, tree‐associated BNF accounted for 0.59 Tg N yr−1, similar to asymbiotic (0.37 Tg N yr−1) and understory symbiotic BNF (0.48 Tg N yr−1), while N deposition contributed 1.68 Tg N yr−1 and rock weathering 0.37 Tg N yr−1. Overall, our results reveal previously uncharacterized spatial patterns in tree BNF that can inform large‐scale N assessments and serve as a model for improving tree‐based BNF estimates worldwide. This updated, lower BNF estimate indicates a greater ratio of anthropogenic to natural N inputs, suggesting an even greater human impact on the N cycle. Key Points: N‐fixing trees in the temperate United States contribute less reactive N than previously thoughtAlnus and Robinia fix the majority of tree‐based N fixation in the United StatesThe flux of fixed N from trees is similar to that from understory plants or asymbiotic fixers across the United States [ABSTRACT FROM AUTHOR]

Symbiotic nitrogen (N)-fixing trees can drive N and carbon cycling and thus are critical components of future climate projections. Despite detailed understanding of how climate influences N-fixation enzyme activity and physiology, comparatively little is known about how climate influences N-fixing tree abundance. Here, we used forest inventory data from the USA and Mexico ( >125,000 plots) along with climate data to address two questions: (1) How does the abundance distribution of N-fixing trees (rhizobial, actinorhizal, and both types together) vary with mean annual temperature ( MAT) and precipitation ( MAP)? (2) How will changing climate shift the abundance distribution of N-fixing trees? We found that rhizobial N-fixing trees were nearly absent below 15°C MAT, but above 15°C MAT, they increased in abundance as temperature rose. We found no evidence for a hump-shaped response to temperature throughout the range of our data. Rhizobial trees were more abundant in dry than in wet ecosystems. By contrast, actinorhizal trees peaked in abundance at 5-10°C MAT and were least abundant in areas with intermediate precipitation. Next, we used a climate-envelope approach to project how N-fixing tree relative abundance might change in the future. The climate-envelope projection showed that rhizobial N-fixing trees will likely become more abundant in many areas by 2080, particularly in the southern USA and western Mexico, due primarily to rising temperatures. Projections for actinorhizal N-fixing trees were more nuanced due to their nonmonotonic dependence on temperature and precipitation. Overall, the dominant trend is that warming will increase N-fixing tree abundance in much of the USA and Mexico, with large increases up to 40° North latitude. The quantitative link we provide between climate and N-fixing tree abundance can help improve the representation of symbiotic N fixation in Earth System Models. [ABSTRACT FROM AUTHOR]

The rarity of nitrogen (N)-fixing trees in frequently N-limited higher-latitude (here, > 35°) forests is a central biogeochemical paradox. One hypothesis for their rarity is that evolutionary constraints limit N-fixing tree diversity, preventing N-fixing species from filling available niches in higher-latitude forests. Here, we test this hypothesis using data from the USA and Mexico. N-fixing trees comprise only a slightly smaller fraction of taxa at higher vs. lower latitudes (8% vs. 11% of genera), despite 11-fold lower abundance (1.2% vs. 12.7% of basal area). Furthermore, N-fixing trees are abundant but belong to few species on tropical islands, suggesting that low absolute diversity does not limit their abundance. Rhizobial taxa dominate N-fixing tree richness at lower latitudes, whereas actinorhizal species do at higher latitudes. Our results suggest that low diversity does not explain N-fixing trees' rarity in higher-latitude forests. Therefore, N limitation in higher-latitude forests likely results from ecological constraints on N fixation. [ABSTRACT FROM AUTHOR]

Symbiotic nitrogen (N) fixation is the major N input to many ecosystems. Although temperate forests are commonly N limited, symbiotic N-fixing trees (“N fixers”) are rare and decline in abundance as succession proceeds–a challenging paradox that remains unexplained. Understanding demographic processes that underlie N fixers’ rarity and successional decline would provide a proximate answer to the paradox. Do N fixers grow slower, die more frequently, or recruit less in temperate forests? We quantified demographic rates of N-fixing and non-fixing trees across succession using U.S. forest inventory data. We used an individual-based model to evaluate the relative contribution of each demographic process to community dynamics. Compared to non-fixers, N fixers had lower growth rates, higher mortality rates, and lower recruitment rates throughout succession. The mortality effect contributed more than the growth effect to N fixers’ successional decline. Canopy and understory N fixers experienced these demographic disadvantages, indicating that factors in addition to light limitation likely contribute to N fixers’ successional decline. We show that the rarity and successional decline of N-fixing trees in temperate forests is due more to their survival disadvantage than their growth disadvantage, and a recruitment disadvantage might also play a large role. [ABSTRACT FROM AUTHOR]

A natural biopolymer bilayer film based on chitosan and bacterial cellulose with a protective layer of pullulan was developed by a two-step solution casting method. Curcumin was incorporated as an active antioxidant and antibacterial agent into the inner layer. The films with different curcumin concentrations were systematically characterized. Fourier transform infrared spectroscopy and X-ray diffraction analyses showed high compatibility between curcumin and the polysaccharide matrix through intermolecular interactions, which was verified by enhanced mechanical and barrier properties. The curcumin incorporation improved the thermal stability by >35.4 %, along with lower visible and ultraviolet light transmittance (< 8.6 %) and water solubility (< 25.1 %). The film had both antibacterial and antioxidant properties, and the sustained release of curcumin was largest (> 58.8 %) in the fatty food simulant lasting for over 155 h. The results suggested that the film containing 0.2 % curcumin had ideal physical and functional properties, suggesting its potential as a novel packaging material for the preservation of high-fat food. [ABSTRACT FROM AUTHOR]

Iron (Fe) deficiency directly affects crop growth and development, ultimately resulting in reduced crop yield and quality. Recently, long non-coding RNAs (lncRNAs) have been demonstrated to play critical regulatory roles in a multitude of pathways across numerous species. However, systematic screening of lncRNAs responding to Fe deficiency and their regulatory mechanism in plants has not been reported. In this work, 171 differently expressed lncRNAs (DE-lncRNAs) were identified based on analysis of strand-specific RNA-seq data from rice shoots and roots under Fe-deficient conditions. We also found several lncRNAs, which could generate miRNAs or act as endogenous target mimics to regulate expression of Fe-related genes. Analysis of interaction networks and gene ontology enrichment revealed that a number of DE-lncRNAs were associated with iron transport and photosynthesis, indicating a possible role of lncRNAs in regulation of Fe homeostasis. Moreover, we identified 76 potential lncRNA targets of OsbHLH156, a key regulator for transcriptional response to Fe deficiency. This study provides insight into the potential functions and regulatory mechanism of Fe-responsive lncRNAs and would be an initial and reference for any further studies regarding lncRNAs involved in Fe deficiency in plants. [ABSTRACT FROM AUTHOR]

A simple but robust ultra-broadband femtosecond optical gating method utilizing transient beam deflection effect is demonstrated with direct CCD imaging of the distorted single-color probe and the measurement of the chirp structure of a white light continuum generated from a CaF₂ plate. The non-collinear configured beam deflection gating technique not only preserves all the advantages of the previous optical Kerr lens based gating methods, such as having no phase matching conditions, little dependence on probe intensity or special nonlinear media, and no requirements on the pump-probe polarization relationship, but it also extends the measurable probe bandwidth. Meanwhile, it is also proved that the current gating technique is easy-aligned, free from the influence of the pump-probe pulse-front mismatch and the probe beam profile, which is much convenient for the characterization of ultra-broadband light pulses in the applications of ultrafast spectroscopy.