A transthyretin-like protein acts downstream of miR397 and LACCASE to regulate grain yield in rice.

Increasing grain yield is a major goal of breeders due to the rising global demand for food. We previously reported that the miR397-LACCASE (OsLAC) module regulates brassinosteroid (BR) signaling and grain yield in rice (Oryza sativa). However, the precise roles of laccase enzymes in the BR pathway remain unclear. Here, we report that OsLAC controls grain yield by preventing the turnover of TRANSTHYRETIN-LIKE (OsTTL), a negative regulator of BR signaling. Overexpressing OsTTL decreased BR sensitivity in rice, while loss-of-function of OsTTL led to enhanced BR signaling and increased grain yield. OsLAC directly binds to OsTTL and regulates its phosphorylation-mediated turnover. The phosphorylation site Ser226 of OsTTL is essential for its ubiquitination and degradation. Overexpressing the dephosphorylation-mimic form of OsTTL (OsTTLS226A) resulted in more severe defects than did overexpressing OsTTL. These findings provide insight into the role of an ancient laccase in BR signaling and suggest that the OsLAC-OsTTL module could serve as a target for improving grain yield.

The auronidin flavonoid pigments of the liverwort Marchantia polymorpha form polymers that modify cell wall properties.

Plant adaptation from aquatic to terrestrial environments required modifications to cell wall structure and function to provide tolerance to new abiotic and biotic stressors. Here, we investigate the nature and function of red auronidin pigment accumulation in the cell wall of the liverwort Marchantia polymorpha. Transgenic plants with auronidin production either constitutive or absent were analysed for their cell wall properties, including fractionation of polysaccharide and phenolic components. While small amounts of auronidin and other flavonoids were loosely associated with the cell wall, the majority of the pigments were tightly associated, similar to what is observed in angiosperms for polyphenolics such as lignin. No evidence of covalent binding to a polysaccharide component was found: we propose auronidin is present in the wall as a physically entrapped large molecular weight polymer. The results suggested auronidin is a dual function molecule that can both screen excess light and increase wall strength, hydrophobicity and resistance to enzymatic degradation by pathogens. Thus, liverworts have expanded the core phenylpropanoid toolkit that was present in the ancestor of all land plants, to deliver a lineage-specific solution to some of the environmental stresses faced from a terrestrial lifestyle.

MicroRNA397 promotes rice flowering by regulating the photorespiration pathway.

The precise timing of flowering plays a pivotal role in ensuring successful plant reproduction and seed production. This process is intricately governed by complex genetic networks that integrate internal and external signals. This study delved into the regulatory function of microRNA397 (miR397) and its target gene LACCASE-15 (OsLAC15) in modulating flowering traits in rice (Oryza sativa). Overexpression of miR397 led to earlier heading dates, decreased number of leaves on the main stem, and accelerated differentiation of the spikelet meristem. Conversely, overexpression of OsLAC15 resulted in delayed flowering and prolonged vegetative growth. Through biochemical and physiological assays, we uncovered that miR397-OsLAC15 had a profound impact on carbohydrate accumulation and photosynthetic assimilation, consequently enhancing the photosynthetic intensity in miR397-overexpressing rice plants. Notably, we identified that OsLAC15 is at least partially localized within the peroxisome organelle, where it regulates the photorespiration pathway. Moreover, we observed that a high CO2 concentration could rescue the late flowering phenotype in OsLAC15-overexpressing plants. These findings shed valuable insights into the regulatory mechanisms of miR397-OsLAC15 in rice flowering and provided potential strategies for developing crop varieties with early flowering and high-yield traits through genetic breeding.

Test-retest reliability of the attention network test from the perspective of intrinsic network organization.

The attention network test (ANT), developed based on the triple-network taxonomy by Posner and colleagues, has been widely used to examine the efficacy of alerting, orienting and executive control in clinical and developmental neuroscience studies. Recent research suggests the imperfect reliability of the behavioural ANT and its variants. However, the classical ANT fMRI task's test-retest reliability has received little attention. Moreover, it remains ambiguous whether the attention-related intrinsic network components, especially the dorsal attention, ventral attention and frontoparietal network, manifest acceptable reliability. The present study approaches these issues by utilizing an openly available ANT fMRI dataset for participants with Parkinson's disease and healthy elderly. The reproducibility of group-level activations across sessions and participant groups and the test-retest reliability at the individual level were examined at the voxel, region and network levels. The intrinsic network was defined using the Yeo-Schaefer atlas. Our results reveal three critical facets: (1) the overlapping of the group-level contrast map between sessions and between participant groups was unsatisfactory; (2) the reliability of alerting, orienting and executive, defined as a contrast between conditions, was worse than estimates of specific conditions. (3) Dorsal attention, ventral attention, visual and somatomotor networks showed acceptable reliability for the congruent and incongruent conditions. Our results suggest that specific condition estimates might be used instead of the contrast map for individual or group-difference studies.

Painted flowers: Eluta generates pigment patterning in Antirrhinum.

In the early 1900s, Erwin Baur established Antirrhinum majus as a model system, identifying and characterising numerous flower colour variants. This included Picturatum/Eluta, which restricts the accumulation of magenta anthocyanin pigments, forming bullseye markings on the flower face. We identified the gene underlying the Eluta locus by transposon-tagging, using an Antirrhinum line that spontaneously lost the nonsuppressive el phenotype. A candidate MYB repressor gene at this locus contained a CACTA transposable element. We subsequently identified plants where this element excised, reverting to a suppressive Eluta phenotype. El alleles inhibit expression of anthocyanin biosynthetic genes, confirming it to be a regulatory locus. The modes of action of Eluta were investigated by generating stable transgenic tobacco lines, biolistic transformation of Antirrhinum petals and promoter activation/repression assays. Eluta competes with MYB activators for promoter cis-elements, and also by titrating essential cofactors (bHLH proteins) to reduce transcription of target genes. Eluta restricts the pigmentation established by the R2R3-MYB factors, Rosea and Venosa, with the greatest repression on those parts of the petals where Eluta is most highly expressed. Baur questioned the origin of heredity units determining flower colour variation in cultivated A. majus. Our findings support introgression from wild species into cultivated varieties.

Ubiquitin-dependent Argonauteprotein MEL1 degradation is essential for rice sporogenesis and phasiRNA target regulation.

MEIOSIS ARRESTED AT LEPTOTENE1 (MEL1), a rice (Oryza sativa) Argonaute (AGO) protein, has been reported to function specifically at premeiotic and meiotic stages of germ cell development and is associated with a novel class of germ cell-specific small noncoding RNAs called phased small RNAs (phasiRNAs). MEL1 accumulation is temporally and spatially regulated and is eliminated after meiosis. However, the metabolism and turnover (i.e. the homeostasis) of MEL1 during germ cell development remains unknown. Here, we show that MEL1 is ubiquitinated and subsequently degraded via the proteasome pathway in vivo during late sporogenesis. Abnormal accumulation of MEL1 after meiosis leads to a semi-sterile phenotype. We identified a monocot-specific E3 ligase, XBOS36, a CULLIN RING-box protein, that is responsible for the degradation of MEL1. Ubiquitination at four K residues at the N terminus of MEL1 by XBOS36 induces its degradation. Importantly, inhibition of MEL1 degradation either by XBOS36 knockdown or by MEL1 overexpression prevents the formation of pollen at the microspore stage. Further mechanistic analysis showed that disrupting MEL1 homeostasis in germ cells leads to off-target cleavage of phasiRNA target genes. Our findings thus provide insight into the communication between a monocot-specific E3 ligase and an AGO protein during plant reproductive development.

CT radiomics-based model for predicting TMB and immunotherapy response in non-small cell lung cancer.

BACKGROUND: Tumor mutational burden (TMB) is one of the most significant predictive biomarkers of immunotherapy efficacy in non-small cell lung cancer (NSCLC). Radiomics allows high-throughput extraction and analysis of advanced and quantitative medical imaging features. This study develops and validates a radiomic model for predicting TMB level and the response to immunotherapy based on CT features in NSCLC. METHOD: Pre-operative chest CT images of 127 patients with NSCLC were retrospectively studied. The 3D-Slicer software was used to outline the region of interest and extract features from the CT images. Radiomics prediction model was constructed by LASSO and multiple logistic regression in a training dataset. The model was validated by receiver operating characteristic (ROC) curves and calibration curves using external datasets. Decision curve analysis was used to assess the value of the model for clinical application. RESULTS: A total of 1037 radiomic features were extracted from the CT images of NSCLC patients from TCGA. LASSO regression selected three radiomics features (Flatness, Autocorrelation and Minimum), which were associated with TMB level in NSCLC. A TMB prediction model consisting of 3 radiomic features was constructed by multiple logistic regression. The area under the curve (AUC) value in the TCGA training dataset was 0.816 (95% CI: 0.7109-0.9203) for predicting TMB level in NSCLC. The AUC value in external validation dataset I was 0.775 (95% CI: 0.5528-0.9972) for predicting TMB level in NSCLC, and the AUC value in external validation dataset II was 0.762 (95% CI: 0.5669-0.9569) for predicting the efficacy of immunotherapy in NSCLC. CONCLUSION: The model based on CT radiomic features helps to achieve cost effective improvement in TMB classification and precise immunotherapy treatment of NSCLC patients.

Nanoplastics alter ecosystem multifunctionality and may increase global warming potential.

Although the presence of nanoplastics in aquatic and terrestrial ecosystems has received increasing attention, little is known about its potential effect on ecosystem processes and functions. Here, we evaluated if differentially charged polystyrene (PS) nanoplastics (PS-NH2 and PS-SO3 H) exhibit distinct influences on microbial community structure, nitrogen removal processes (denitrification and anammox), emissions of greenhouse gases (CO2 , CH4 , and N2 O), and ecosystem multifunctionality in soils with and without earthworms through a 42-day microcosm experiment. Our results indicated that nanoplastics significantly altered soil microbial community structure and potential functions, with more pronounced effects for positively charged PS-NH2 than for negatively charged PS-SO3 H. Ecologically relevant concentration (3 g kg-1 ) of nanoplastics inhibited both soil denitrification and anammox rates, while environmentally realistic concentration (0.3 g kg-1 ) of nanoplastics decreased the denitrification rate and enhanced the anammox rate. The soil N2 O flux was always inhibited 6%-51% by both types of nanoplastics, whereas emissions of CO2 and CH4 were enhanced by nanoplastics in most cases. Significantly, although N2 O emissions were decreased by nanoplastics, the global warming potential of total greenhouse gases was increased 21%-75% by nanoplastics in soils without earthworms. Moreover, ecosystem multifunctionality was increased 4%-12% by 0.3 g kg-1 of nanoplastics but decreased 4%-11% by 3 g kg-1 of nanoplastics. Our findings provide the only evidence to date that the rapid increase in nanoplastics is altering not only ecosystem structure and processes but also ecosystem multifunctionality, and it may increase the emission of CO2 and CH4 and their global warming potential to some extent.

OsmiR528 regulates rice-pollen intine formation by targeting an uclacyanin to influence flavonoid metabolism.

The intine, the inner layer of the pollen wall, is essential for the normal development and germination of pollen. However, the composition and developmental regulation of the intine in rice (Oryza sativa) remain largely unknown. Here, we identify a microRNA, OsmiR528, which regulates the formation of the pollen intine and thus male fertility in rice. The mir528 knockout mutant aborted pollen development at the late binucleate pollen stage, significantly decreasing the seed-setting rate. We further demonstrated that OsmiR528 affects pollen development by directly targeting the uclacyanin gene OsUCL23 (encoding a member of the plant-specific blue copper protein family of phytocyanins) and regulating intine deposition. OsUCL23 overexpression phenocopied the mir528 mutant. The OsUCL23 protein localized in the prevacuolar compartments (PVCs) and multivesicular bodies (MVBs). We further revealed that OsUCL23 interacts with a member of the proton-dependent oligopeptide transport (POT) family of transporters to regulate various metabolic components, especially flavonoids. We propose a model in which OsmiR528 regulates pollen intine formation by directly targeting OsUCL23 and in which OsUCL23 interacts with the POT protein on the PVCs and MVBs to regulate the production of metabolites during pollen development. The study thus reveals the functions of OsmiR528 and an uclacyanin during pollen development.

Stress, senescence, and specialized metabolites in bryophytes.

Life on land exposes plants to varied abiotic and biotic environmental stresses. These environmental drivers contributed to a large expansion of metabolic capabilities during land plant evolution and species diversification. In this review we summarize knowledge on how the specialized metabolite pathways of bryophytes may contribute to stress tolerance capabilities. Bryophytes are the non-tracheophyte land plant group (comprising the hornworts, liverworts, and mosses) and rapidly diversified following the colonization of land. Mosses and liverworts have as wide a distribution as flowering plants with regard to available environments, able to grow in polar regions through to hot desert landscapes. Yet in contrast to flowering plants, for which the biosynthetic pathways, transcriptional regulation, and compound function of stress tolerance-related metabolite pathways have been extensively characterized, it is only recently that similar data have become available for bryophytes. The bryophyte data are compared with those available for angiosperms, including examining how the differing plant forms of bryophytes and angiosperms may influence specialized metabolite diversity and function. The involvement of stress-induced specialized metabolites in senescence and nutrient response pathways is also discussed.

Early-Onset Micromorphological Changes of Neuronal Fiber Bundles During Radiotherapy.

BACKGROUND: Patients receiving cranial radiation face the risk of delayed brain dysfunction. However, an early medical imaging marker is not available until irreversible morphological changes emerge. PURPOSE: To explore the micromorphological white matter changes during the radiotherapy session by utilizing an along-tract analysis framework. STUDY TYPE: Prospective. POPULATION: Eighteen nasopharyngeal carcinoma (two female) patients receiving cranial radiation. FIELD STRENGTH/SEQUENCE: 3.0 T; Diffusion tensor imaging (DTI) and T1- and T2-weighted images (T1W, T2W); computed tomography (CT). ASSESSMENT: Patients received three DTI imaging scans during the radiotherapy (RT), namely the baseline scan (1-2 days before RT began), the middle scan (the middle of the RT session), and the end scan (1-2 days after RT ended). Twelve fibers were segmented after whole-brain tractography. Then, the fractional anisotropy (FA) values and the cumulative radiation dose received for each fiber streamline were resampled and projected into their center fiber. STATISTICAL TESTS: The contrast among the three scans (P1: middle scan-baseline scan; P2: end scan-middle scan; P3: end scan-baseline scan) were compared using the linear mixed model for each of the 12 center fibers. Then, a dose-responsiveness relationship was performed using Pearson correlation. P < 0.05 was considered statistically significant. RESULTS: Six of the 12 center fibers showed significant changes of FA values during the RT but with heterogeneous patterns. The significant changes along a specific center fiber were associated with their cumulative dose received (Genu: P1 r = -0.6182, P2 r = -0.5907; Splenium: P1 r = 0.4055, P = 0.1063, P2 r = 0.6742; right uncinate fasciculus: P1 r = -0.3865, P2 r = -0.4912, P = 0.0533; right corticospinal tract: P1 r = 0.4273, P = 0.1122, P2 r = -0.6885). DATA CONCLUSION: The along-tract analysis might provide sensitive measures on the early-onset micromorphological changes. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

Evolution and function of red pigmentation in land plants.

BACKGROUND: Land plants commonly produce red pigmentation as a response to environmental stressors, both abiotic and biotic. The type of pigment produced varies among different land plant lineages. In the majority of species they are flavonoids, a large branch of the phenylpropanoid pathway. Flavonoids that can confer red colours include 3-hydroxyanthocyanins, 3-deoxyanthocyanins, sphagnorubins and auronidins, which are the predominant red pigments in flowering plants, ferns, mosses and liverworts, respectively. However, some flowering plants have lost the capacity for anthocyanin biosynthesis and produce nitrogen-containing betalain pigments instead. Some terrestrial algal species also produce red pigmentation as an abiotic stress response, and these include both carotenoid and phenolic pigments. SCOPE: In this review, we examine: which environmental triggers induce red pigmentation in non-reproductive tissues; theories on the functions of stress-induced pigmentation; the evolution of the biosynthetic pathways; and structure-function aspects of different pigment types. We also compare data on stress-induced pigmentation in land plants with those for terrestrial algae, and discuss possible explanations for the lack of red pigmentation in the hornwort lineage of land plants. CONCLUSIONS: The evidence suggests that pigment biosynthetic pathways have evolved numerous times in land plants to provide compounds that have red colour to screen damaging photosynthetically active radiation but that also have secondary functions that provide specific benefits to the particular land plant lineage.

The subunit of RNA N6-methyladenosine methyltransferase OsFIP regulates early degeneration of microspores in rice.

N6-Methyladenosine (m6A) RNA methylation plays important roles during development in different species. However, knowledge of m6A RNA methylation in monocots remains limited. In this study, we reported that OsFIP and OsMTA2 are the components of m6A RNA methyltransferase complex in rice and uncovered a previously unknown function of m6A RNA methylation in regulation of plant sporogenesis. Importantly, OsFIP is essential for rice male gametogenesis. Knocking out of OsFIP results in early degeneration of microspores at the vacuolated pollen stage and simultaneously causes abnormal meiosis in prophase I. We further analyzed the profile of rice m6A modification during sporogenesis in both WT and OsFIP loss-of-function plants, and identified a rice panicle specific m6A modification motif "UGWAMH". Interestingly, we found that OsFIP directly mediates the m6A methylation of a set of threonine protease and NTPase mRNAs and is essential for their expression and/or splicing, which in turn regulates the progress of sporogenesis. Our findings revealed for the first time that OsFIP plays an indispensable role in plant early sporogenesis. This study also provides evidence for the different functions of the m6A RNA methyltransferase complex between rice and Arabidopsis.

Auronidins are a previously unreported class of flavonoid pigments that challenges when anthocyanin biosynthesis evolved in plants.

Anthocyanins are key pigments of plants, providing color to flowers, fruit, and foliage and helping to counter the harmful effects of environmental stresses. It is generally assumed that anthocyanin biosynthesis arose during the evolutionary transition of plants from aquatic to land environments. Liverworts, which may be the closest living relatives to the first land plants, have been reported to produce red cell wall-bound riccionidin pigments in response to stresses such as UV-B light, drought, and nutrient deprivation, and these have been proposed to correspond to the first anthocyanidins present in early land plant ancestors. Taking advantage of the liverwort model species Marchantia polymorpha, we show that the red pigments of Marchantia are formed by a phenylpropanoid biosynthetic branch distinct from that leading to anthocyanins. They constitute a previously unreported flavonoid class, for which we propose the name "auronidin," with similar colors as anthocyanin but different chemistry, including strong fluorescence. Auronidins might contribute to the remarkable ability of liverworts to survive in extreme environments on land, and their discovery calls into question the possible pigment status of the first land plants.

A Natural Variant of miR397 Mediates a Feedback Loop in Circadian Rhythm.

MicroRNAs (miRNAs) are small noncoding RNAs of ∼21 nt in length, which have regulatory roles in many biological processes. In animals, proper functioning of the circadian clock, which is closely linked to the fitness of almost all living organisms, is regulated by miRNAs. However, to date, there have been no reports of the roles of miRNA in regulation of the plant circadian rhythm. Here, we report a natural variant of miR397 that lengthens the circadian period and controls flowering time in Arabidopsis (Arabidopsis thaliana). Highly conserved among angiosperms, the miRNA miR397 has two members in Arabidopsis: miR397a and miR397b. However, only miR397b significantly delayed flowering. Our results suggest that miR397b controls flowering by targeting CASEIN KINASE II SUBUNIT BETA3 (CKB3), in turn modulating the circadian period of CIRCADIAN CLOCK ASSOCIATED1 (CCA1). We further demonstrated that CCA1 directly bound to the promoter of MIR397B and suppressed its expression, forming a miR397b-CKB3-CCA1 circadian regulation feedback circuit. Evolutionary analysis revealed that miR397b is a newly evolved genetic variant in Arabidopsis, and the miR397b targeting mode may have a role in enhancing plant fitness. Our results provide evidence for miRNA-mediated circadian regulation in plants and suggest the existence of a feedback loop to manipulate plant flowering through the regulation of circadian rhythm.

circMYBL2, a circRNA from MYBL2, regulates FLT3 translation by recruiting PTBP1 to promote FLT3-ITD AML progression.

Internal tandem duplication (ITD) mutations within FMS-like tyrosine kinase-3 (FLT3) occur in up to 30% of acute myeloid leukemia (AML) patients and confer a very poor prognosis. The oncogenic form of FLT3 is an important therapeutic target, and inhibitors specifically targeting FLT3 kinase can induce complete remission; however, relapse after remission has been observed due to acquired resistance with secondary mutations in FLT3, highlighting the need for new strategies to target FLT3-ITD mutations. Recent studies have reported that the aberrant formations of circular RNAs (circRNAs) are biological tumorigenesis-relevant mechanisms and potential therapeutic targets. Herein, we discovered a circRNA, circMYBL2, derived from the cell-cycle checkpoint gene MYBL2. circMYBL2 is more highly expressed in AML patients with FLT3-ITD mutations than in those without the FLT3-ITD mutation. We found that circMYBL2 knockdown specifically inhibits proliferation and promotes the differentiation of FLT3-ITD AML cells in vitro and in vivo. Interestingly, we found that circMYBL2 significantly influences the protein level of mutant FLT3 kinase, which contributes to the activation of FLT3-ITD-dependent signaling pathways. Mechanistically, circMYBL2 enhanced the translational efficiency of FLT3 kinase by increasing the binding of polypyrimidine tract-binding protein 1 (PTBP1) to FLT3 messenger RNA. Moreover, circMYBL2 knockdown impaired the cytoactivity of inhibitor-resistant FLT3-ITD+ cells, with a significant decrease in FLT3 kinase expression, followed by the inactivation of its downstream pathways. In summary, we are the first to reveal a circRNA that specifically influences FLT3-ITD AML and regulates FLT3 kinase levels through translational regulation, suggesting that circMYBL2 may be a potential therapeutic target for FLT3-ITD AML.

The Fractional CO2 Laser for the Treatment of Genitourinary Syndrome of Menopause: A Prospective Multicenter Cohort Study.

BACKGROUND AND OBJECTIVES: Genitourinary syndrome of menopause (GSM) is a common condition affecting of most postmenopausal women, which greatly impacks the quality of life,and need to treat. This prospective multicenter cohort study aimed to compare the efficacy and safety of the fractional carbon dioxide (CO2 ) laser with that of topical estrogen for vaginal treatment and relieving symptoms of genitourinary syndrome of menopause (GSM). STUDY DESIGN/MATERIALS AND METHODS: This study included 162 postmenopausal patients who received vaginal laser or topical Estriol cream therapy between January 2017 and May 2019 at eight study centers in China. The degree of GSM-related symptoms (vaginal burning, dryness, and dyspareunia) was evaluated using the Vaginal Health Index score (VHIS) and Visual Analog Scale (VAS) at baseline, 1, 3, 6, and 12 months posttreatment. The primary endpoint was the improvement in vaginal burning, dryness, and dyspareunia at 6 months after treatment. Multivariate logistic regression was used to compare the rate of improvement in the two groups. RESULTS: At baseline, the laser and control groups showed no significant difference in the mean age, time after menopause, and the VHIS (all P > 0.05). In the laser group, compared with baseline, significant differences were seen in the VHIS after the first or second treatment session and at 1, 3, 6, and 12 months posttreatment (P < 0.01). In the control group, compared with baseline, the VHIS showed significant differences after 1, 3, and 6 months of treatment (P < 0.05). However, there was no significant difference after 3 and 6 months of follow-up between the two groups (P > 0.05). The VHIS scores were significantly higher after 1 month (16.63 ± 2.79 vs. 15.57 ± 2.43) and 12 months (15.72 ± 2.59 vs. 12.12 ± 4.08) of treatment in both the groups (P < 0.05). At 6 months after treatment, both groups showed improvement in vaginal burning, vaginal dryness, and dyspareunia (P > 0.05). The VAS findings at 6 months posttreatment were significantly different when compared with the pretreatment findings (P < 0.001). There were no significant adverse effects in the two groups. CONCLUSIONS: Fractional CO2 laser vaginal treatment could be a safe and effective option for treating symptoms of GSM, including vaginal burning, dryness, and dyspareunia. The improvement in symptoms was comparable with that seen with topical estrogen therapy and lasted for at least 6-12 months posttreatment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Genome-Wide Analysis Identified a Set of Conserved lncRNAs Associated with Domestication-Related Traits in Rice.

Crop domestication, which gives rise to a number of desirable agronomic traits, represents a typical model system of plant evolution. Numerous genomic evidence has proven that noncoding RNAs such as microRNAs and phasiRNAs, as well as protein-coding genes, are selected during crop domestication. However, limited data shows plant long noncoding RNAs (lncRNAs) are also involved in this biological process. In this study, we performed strand-specific RNA sequencing of cultivated rice Oryza sativa ssp. japonica and O. sativa ssp. indica, and their wild progenitor O. rufipogon. We identified a total of 8528 lncRNAs, including 4072 lncRNAs in O. rufipogon, 2091 lncRNAs in japonica rice, and 2365 lncRNAs in indica rice. The lncRNAs expressed in wild rice were revealed to be shorter in length and had fewer exon numbers when compared with lncRNAs from cultivated rice. We also identified a number of conserved lncRNAs in the wild and cultivated rice. The functional study demonstrated that several of these conserved lncRNAs are associated with domestication-related traits in rice. Our findings revealed the feature and conservation of lncRNAs during rice domestication and will further promote functional studies of lncRNAs in rice.

Transcriptional landscape of pathogen-responsive lncRNAs in rice unveils the role of ALEX1 in jasmonate pathway and disease resistance.

Plant defence is multilayered and is essential for surviving in a changing environment. The discovery of long noncoding RNAs (lncRNAs) has dramatically extended our understanding of post-transcriptional gene regulation in diverse biological processes. However, the expression profile and function of lncRNAs in disease resistance are still largely unknown, especially in monocots. Here, we performed strand-specific RNA sequencing of rice leaves infected by Xanthomonas oryzae pv. Oryzae (Xoo) in different time courses and systematically identified 567 disease-responsive rice lncRNAs. Target analyses of these lncRNAs showed that jasmonate (JA) pathway was significantly enriched. To reveal the interaction between lncRNAs and JA-related genes, we studied the coexpression of them and found 39 JA-related protein-coding genes to be interplayed with 73 lncRNAs, highlighting the potential modulation of lncRNAs in JA pathway. We subsequently identified an lncRNA, ALEX1, whose expression is highly induced by Xoo infection. A T-DNA insertion line constructed using enhancer trap system showed a higher expression of ALEX1 and exerted a significant resistance to rice bacterial blight. Functional study revealed that JA signalling is activated and the endogenous content of JA and JA-Ile is increased. Overexpressing ALEX1 in rice further confirmed the activation of JA pathway and resistance to bacterial blight. Our findings reveal the expression of pathogen-responsive lncRNAs in rice and provide novel insights into the connection between lncRNAs and JA pathway in the regulation of plant disease resistance.

New Perspective on the Nanoplastics Disrupting the Reproduction of an Endangered Fern in Artificial Freshwater.

The potential risks of micro/nanoplastics on the ecological environment, particularly aquatic fauna, have been realized in recent years. However, information about its potential effects on aquatic plants is scarce. In this study, a four-week exposure experiment was conducted to investigate the effects of varying polystyrene nanoplastics concentration (PS-NPs, 0-100 µg/mL) on the early development of an endangered aquatic plant, Ceratopteris pteridoides. Fluorescent observations demonstrated that PS-NPs were adsorbed and accumulated on the spore surface of C. pteridoides rapidly and massively with increasing exposure concentration and time. The adsorption and accumulation of PS-NPs on the spore surface posed a negative effect on spore imbibition, causing 2.3-22.4% reduction in final spore size. Spore germination and gametophyte sex differentiation were both negatively affected by PS-NP exposure, resulting in 10.4-88.0% inhibition in germination ratio and 2.9-53.4% reduction in hermaphroditic gametophyte ratio. Additionally, PS-NPs were observed to penetrate into the roots of gametophytes. Higher concentration of PS-NPs (100 µg/mL) can even induce pathological changes on gametophytes, although with a low incidence (4.9%). The results above indicated that exposure to PS-NPs caused a series of disruptions from the spore imbibition to germination and gametophyte stages, and are likely to pose an eco-physiological risk on the reproductive success of endangered ferns.