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This study was designed to evaluate the effects of epiphytic microbiota from Italian ryegrass (IRIR), Napier grass (IRNP) and Sudan grass (IRSD) on ensiling characteristics and microbial community of Italian ryegrass silage. Each treatment was prepared in triplicate and ensiled in plastic bag silos for 1, 3, 7, 14, 30 and 60 days. The γ-ray irradiation sterilization method, microbiota transplantation and next generation sequencing technology were used. Results indicated that significantly (P < 0.05) higher ratio of lactic acid to acetic acid, and lower acetic acid and ammonia nitrogen contents were observed in IRNP than IRIR and IRSD after 60 days of ensiling. Lactobacillus was the most predominant in each treatment at the late stage of fermentation. Lactococcus was eventually replaced by Lactobacillus in IRSD, whereas higher abundance of Lactococcus was continuously found in IRNP. Co-occurrence network analysis demonstrated Lactococcus was pivotal in determining the silage fermentation pattern of Italian ryegrass. According to the 16S rRNA gene-predicted functional profiles, the metabolism of amino acids was enhanced by the epiphytic microbiota from Italian ryegrass and Sudan grass, while the carbohydrate metabolism was accelerated by the epiphytic microbiota from Napier grass. Overall, IRNP had a homo-fermentative process, whereas IRIR and IRSD possessed a hetero-fermentative pattern. The Lactococcus and heterofermentative Lactobacillus were mainly responsible for this. It also confirmed that the exogenous microorganisms that promote the carbohydrate metabolism and inhibit the metabolism of amino acids could be a good potential source to improve the silage quality of temperate grass.

• While it is known that interactions between plants and soil fungi drive many essential ecosystem functions, considerable uncertainty exists over the drivers of fungal community composition in the rhizosphere. Here, we examined the roles of plant species identity, phylogeny and functional traits in shaping rhizosphere fungal communities and tested the robustness of these relationships to environmental change. • We conducted a glasshouse experiment consisting of 21 temperate grassland species grown under three different environmental treatments and characterised the fungal communities within the rhizosphere of these plants. • We found that plant species identity, plant phylogenetic relatedness and plant traits all affected rhizosphere fungal community composition. Trait relationships with fungal communities were primarily driven by interactions with arbuscular mycorrhizal fungi, and root traits were stronger predictors of fungal communities than leaf traits. These patterns were independent of the environmental treatments the plants were grown under. • Our results showcase the key role of plant root traits, especially root diameter, root nitrogen and specific root length, in driving rhizosphere fungal community composition, demonstrating the potential for root traits to be used within predictive frameworks of plant–fungal relationships. Furthermore, we highlight how key limitations in our understanding of fungal function may obscure previously unmeasured plant–fungal interactions

This minireview highlights the importance of endophytic fungi for sustainable agriculture and horticulture production. Fungal endophytes play a key role in habitat adaptation of plants resulting in improved plant performance and plant protection against biotic and abiotic stresses. They encode a vast variety of novel secondary metabolites including volatile organic compounds. In addition to protecting plants against pathogens and pests, selected fungal endophytes have been used to remove animal toxicities associated with fungal endophytes in temperate grasses, to create corn and rice plants that are tolerant to a range of biotic and abiotic stresses, and for improved management of post-harvest control. We argue that practices used in plant breeding, seed treatments and agriculture, often caused by poor knowledge of the importance of fungal endophytes, are among the reasons for the loss of fungal endophyte diversity in domesticated plants and also accounts for the reduced effectiveness of some endophyte strains to confer plant benefits. We provide recommendations on how to mitigate against these negative impacts in modern agriculture. An aniline-blue leaf sheath peel of an Epichloe species growing between plant cells.

FLOWERING LOCUS T2 (FT2) is the closest paralog of the FT1 flowering gene in the temperate grasses. Here we show that overexpression of FT2 in Brachypodium distachyon and barley results in precocious flowering and reduced spikelet number, while down-regulation by RNA interference results in delayed flowering and a reduced percentage of filled florets. Similarly, truncation mutations of FT2 homeologs in tetraploid wheat delayed flowering (2–4 d) and reduced fertility. The wheat ft2 mutants also showed a significant increase in the number of spikelets per spike, with a longer spike development period potentially contributing to the delayed heading time. In the wheat leaves, FT2 was expressed later than FT1, suggesting a relatively smaller role for FT2 in the initiation of the reproductive phase. FT2 transcripts were detected in the shoot apical meristem and increased during early spike development. Transversal sections of the developing spike showed the highest FT2 transcript levels in the distal part, where new spikelets are formed. Our results suggest that, in wheat, FT2 plays an important role in spike development and fertility and a limited role in the timing of the transition between the vegetative and reproductive shoot apical meristem.

Aim Successful colonization after long-distance dispersal (LDD) depends on the availability of suitable habitats and competitive ability. In this study, we address the hypothesis that two widely distributed sister grass lineages (broad- and fine-leaved Loliinae; hereafter BL and FL) that differ in their habitat requirements and competitive ability also differ in their biogeographic history, with particular reference to LDD. Location Global. Methods We reconstructed a comprehensive phylogeny of Loliinae, based on nuclear and plastid markers and estimated divergence times using fossil calibrations. Biogeographical events were estimated using analysis of range evolution, comparing different models. Numbers and rates of dispersals were estimated for BL and FL using stochastic mapping with best-performing and baseline biogeographical models, and examined for correlation with distance, disjunction type, and phenotypic syndrome. Results The most recent common ancestor of Loliinae likely split at the Oligocene-Miocene transition (22.50 ± 3.95 Ma), pre-dating previous estimates, whereas the ancestors of the BL and FL Loliinae likely began to diversify in the Early Miocene (18.91 ± 4.15 and 17.50 ± 3.50 Ma, respectively). A model of range evolution integrating founder events and scaling of dispersal by shortest distance between areas performed best amongst a set of alternative models and recovered a mean of 83 dispersal events in Loliinae. Overall dispersal rates were significantly higher in BL than in FL. Per-route dispersal rates showed a significant negative exponential relationship to shortest distance but were not affected by phenotypic syndrome or disjunction type. Main conclusions Loliinae originated in the Northern Hemisphere and evolved through recurrent LDDs. Higher competitive ability, potentially related to the broad-leaved syndrome (i.e. tall strong-rhizomatous plants, long-living individuals, occupancy of more stable habitats), may explain higher observed dispersal rates in BL compared with FL Loliinae. However, the dominant factor impacting dispersal in both BL and FL Loliinae is the distance between suitable areas.

The proper timing of flowering, which is key to maximize reproductive success and yield, relies in many plant species on the coordination between environmental cues and endogenous developmental programs. The perception of changes in day length is one of the most reliable cues of seasonal change, and this involves the interplay between the sensing of light signals and the circadian clock. Here, we describe a Brachypodium distachyon mutant allele of the evening complex protein EARLY FLOWERING 3 (ELF3). We show that the elf3 mutant flowers more rapidly than wild type plants in short days as well as under longer photoperiods but, in very long (20 h) days, flowering is equally rapid in elf3 and wild type. Furthermore, flowering in the elf3 mutant is still sensitive to vernalization, but not to ambient temperature changes. Molecular analyses revealed that the expression of a short-day marker gene is suppressed in elf3 grown in short days, and the expression patterns of clock genes and flowering time regulators are altered. We also explored the mechanisms of photoperiodic perception in temperate grasses by exposing B. distachyon plants grown under a 12 h photoperiod to a daily night break consisting of a mixture of red and far-red light. We showed that 2 h breaks are sufficient to accelerate flowering in B. distachyon under non-inductive photoperiods and that this acceleration of flowering is mediated by red light. Finally, we discuss advances and perspectives for research on the perception of photoperiod in temperate grasses.

Brachypodium distachyon is a model plant for studying temperate grass cereals. Although the transcriptome of plant callus formation-related genes has been extensively studied, information on their regulation is largely unavailable. We conducted assays of callus morphology, the transcriptome, and open chromatin in seeds whose endosperm was removed (sheared seeds), revealing a significant improvement in callus formation. Genome-wide assays of DNase I-hypersensitive sites (DHSs) demonstrated that their landscapes were not substantially disturbed in the sheared seeds. By comparison, 256 and 422 sheared seed-specific DHSs were identified from the early (2d) and late (8d) stages of callus formation, respectively. Twenty-one and 43 binding motifs of transcription factors (TFs) were predicted by mining these sheared seed-specific DHSs. Functional annotation revealed that these TFs were well known to be involved in jasmonic acid, gibberellic acid, and abscisic acid signaling pathways, highlighting the potential roles of these hormones in promoting callus formation in B. distachyon . Transcriptional regulatory networks were developed by interaction assays on these TFs. Six TFs (MYC3, LRL1, BBM, RGA1, IDD2, and ABI5) showed strong causal connections, suggesting their possible roles in regulatory networks. Overall, we provided experimental annotations of 19,574 DHSs and 55 derived TF binding motifs related to callus formation in B. distachyon , which can serve as a valuable resource for elucidating the transcriptional networks that function in callus formation and other physiological processes. Keymessage Seed shearing enhances callus formation triggered by transcription factors related to jasmonic acid, gibberellic acid, and abscisic acid signaling pathways.

Abstract Extra-pair paternity (EPP) is frequent in socially monogamous birds with biparental care. However, males should avoid providing care to unrelated offspring. In this study, we first analyzed the relationship between parental care and paternity loss, and secondly, we evaluated if males adjust parental care to a perceived threat of cuckoldry. Over three breeding seasons, we intensively studied a color-banded population of south temperate grass wrens Cistothorus platensis. We monitored nests attended by socially monogamous males, collected blood samples from adults and nestlings, and recorded male provisioning rates to the nestlings. Paternity was assigned genetically using SNP markers. We simulated territorial intrusions during the female fertile period (egg-laying) to manipulate males’ perceived threat of cuckoldry. Neither the proportion of extra-pair offspring nor the presence/absence of extra-pair offspring in the nest affected male provisioning rates, suggesting that males did not adjust parental effort to actual paternity loss. Simulated territorial intrusions revealed that males were more likely to approach and attack a conspecific than a heterospecific stuffed decoy. However, experimental and control males provided food to their nestlings at similar rates. Retaliatory reduction of paternal care might not have evolved in grass wrens given the low frequency of extra-pair paternity (23%). Alternatively, males may rely predominately on precopulatory strategies (e.g., territoriality and mate guarding) to prevent females from obtaining extra-pair fertilizations.Significance statementA central tenet in the study of extra-pair behavior in birds is that males should reduce their parental contribution when females engage in extra-pair copulations. Males are thought to use indirect clues (female absences, male intrusions) and direct clues (observation of copulations) to gauge paternity loss. We studied the relationship between extra-pair behavior and male contribution to feeding nestlings in a Neotropical population of grass wrens. We found that males did not adjust their contribution to paternal care based on actual paternity loss. Moreover, simulated male intrusions during the female fertile period, which influence a male’s perceived threat of cuckoldry, did not affect paternal care. Our results suggest that male grass wrens do not indirectly retaliate against females who engage in extra-pair behavior by reducing parental care.

Perception of seasonal cues is critical for reproductive success in many plants. Exposure to winter cold is a cue that can confer competence to flower in the spring via a process known as vernalization. In certain grasses, exposure to short days is another winter cue that can lead to a vernalized state. In Brachypodium distachyon, we find that natural variation for the ability of short days to confer competence to flower is due to allelic variation of the FLOWERING LOCUS T (FT1) paralog FT-like9 (FTL9). An active FTL9 allele is required for the acquisition of floral competence, demonstrating a novel role for a member of the FT family of genes. Loss of the short-day vernalization response appears to have arisen once in B. distachyon and spread through diverse lineages indicating that this loss has adaptive value, perhaps by delaying spring flowering until the danger of cold damage to flowers has subsided.

PurposePlant inputs provide the main food and energy for soil organisms. Considering substantial aboveground litter on the soil surface but few belowground input in the non-growing season, we hypothesize that aboveground input would have an important role in sustaining microbial abundance and community at this period.MethodsWe initiated a manipulative temperate grass experiment with four types of plant inputs, i.e., no input (NI), only belowground input (+B), only aboveground input (+A), and both aboveground and belowground inputs (+A +B) in 2018. We tested whether plant aboveground input plays an important role in maintaining soil microorganisms in the non-growing season, i.e., before and after the growing season of 2019.ResultsMicrobial activities, abundance, composition, and diversity were all similar among the four plant treatments before the growing season. However, after the growing season, microbial activity and diversity were higher at the plots with belowground input (+B and +A +B) than at those without belowground input (+A and NI). Similarly, the abundance of saprophytic fungi, AM fungi, and gram-positive bacteria were larger in the plots with belowground input than NI plot. Microbial community composition was similar between +B and +A +B plots (with belowground input), but they were different with those at +A and NI plots (without belowground input). These results indicated that belowground plant input plays a determining role in maintaining soil microorganisms after the growing season. This may link with the legacy of the rhizodeposition carbon in the growing season.ConclusionWe demonstrate that aboveground input does not play a substantial role in maintaining soil microbial community in the non-growing season, although aboveground input amount dominates relative to belowground input.