Post-transcriptional regulation of grain weight and shape by the RBP-A-J-K complex in rice.

RNA-binding proteins (RBPs) are components of the post-transcriptional regulatory system, but their regulatory effects on complex traits remain unknown. Using an integrated strategy involving map-based cloning, functional characterizations, and transcriptomic and population genomic analyses, we revealed that RBP-K (LOC_Os08g23120), RBP-A (LOC_Os11g41890), and RBP-J (LOC_Os10g33230) encode proteins that form an RBP-A-J-K complex that negatively regulates rice yield-related traits. Examinations of the RBP-A-J-K complex indicated RBP-K functions as a relatively non-specific RBP chaperone that enables RBP-A and RBP-J to function normally. Additionally, RBP-J most likely affects GA pathways, resulting in considerable increases in grain and panicle lengths, but decreases in grain width and thickness. In contrast, RBP-A negatively regulates the expression of genes most likely involved in auxin-regulated pathways controlling cell wall elongation and carbohydrate transport, with substantial effects on the rice grain filling process as well as grain length and weight. Evolutionarily, RBP-K is relatively ancient and highly conserved, whereas RBP-J and RBP-A are more diverse. Thus, the RBP-A-J-K complex may represent a typical functional model for many RBPs and protein complexes that function at transcriptional and post-transcriptional levels in plants and animals for increased functional consistency, efficiency, and versatility, as well as increased evolutionary potential. Our results clearly demonstrate the importance of RBP-mediated post-transcriptional regulation for the diversity of complex traits. Furthermore, rice grain yield and quality may be enhanced by introducing various complete or partial loss-of-function mutations to specific RBP genes using clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9 technology and by exploiting desirable natural tri-genic allelic combinations at the loci encoding the components of the RBP-A-J-K complex through marker-assisted selection.

A Natural Variation in PLEIOTROPIC DEVELOPMENTAL DEFECTS Uncovers a Crucial Role for Chloroplast tRNA Modification in Translation and Plant Development.

The modification of tRNA is important for accurate, efficient protein translation. A number of tRNA-modifying enzymes were found to influence various developmental processes in distinct organisms. However, few genetic or molecular studies have focused on genes encoding tRNA-modifying enzymes in green plant organelles. Here, we discovered that PDD OL , a natural variation allele of PLEIOTROPIC DEVELOPMENTAL DEFECTS (PDD), leads to pleiotropic developmental defects in a near-isogenic line (NIL) generated by introgressing the wild rice Oryza longistaminata into the rice (Oryza sativa) cv 187R. Map-based cloning revealed that PDD encodes an evolutionarily conserved tRNA-modifying GTPase belonging to the tRNA modification E family. The function of PDD was further confirmed by genetic complementation experiments and mutant analysis. PDD mRNA is primarily expressed in leaves, and PDD is localized to chloroplasts. Biochemical analyses indicated that PDD187R forms homodimers and has strong GTPase activity, whereas PDDOL fails to form homodimers and has weak GTPase activity. Liquid chromatography-coupled tandem quadrupole mass spectrometry revealed that PDD is associated with the 5-methylaminomethyl-2-thiouridine modification of chloroplast tRNA. Furthermore, compared to 187R, NIL-PDD OL has severely reduced levels of proteins involved in photosynthesis and ribosome biogenesis but increased levels of plastid-encoded RNA polymerase subunits. Finally, we demonstrate that the defect due to PDD OL alters chloroplast gene expression, thereby affecting communication between the chloroplast and the nucleus.

Virtual Reality in Treatment for Psychological Problems in First-Line Health Care Professionals Fighting COVID-19 Pandemic: A Case Series.

ABSTRACT: Virtual reality therapy (VRT) is a new psychotherapeutic approach integrating virtual reality technology and psychotherapy. This case series aimed to study effectiveness of VRT in treating psychological problems. We described four cases of first-line health care professionals with emerging clinically significant early psychological problems during the COVID-19 outbreak, and specifically received the VRT treatment. We compared the Patient Health Questionnaire 9 items (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), PHQ-15, and Athens Insomnia Scale to evaluate psychological symptoms and sleep quality before and after sessions. All four cases showed a reduction in scale comparison. General scores of the PHQ-9 reduced 65%, GAD-7 reduced 52.17%, PHQ-15 decreased 38.17%, and scores of the Athens Insomnia Scale reduced 67.44%. Meanwhile, a reduction in depression, anxiety, psychosomatic, and sleeping symptoms was also found, which decreased 76.92% in general. These results are highly significant statistically. This case series demonstrated the effectiveness of VRT on psychological problems as a promising approach to apply on various psychological distress and disorders.

Recent advances of noble-metal-free bifunctional oxygen reduction and evolution electrocatalysts.

Oxygen reduction and evolution reactions constitute the core process of many vital energy storage or conversion techniques. However, the kinetic sluggishness of the oxygen redox reactions and heavy reliance on noble-metal-based electrocatalysts strongly limit the energy efficiency of the related devices. Developing high-performance noble-metal-free bifunctional ORR and OER electrocatalysts has gained worldwide attention, where much important progress has been made during the last decade. This review systematically addresses the design principles to obtain high-performance noble-metal-free bifunctional oxygen electrocatalysts by emphasizing strategies of both intrinsic activity regulation and active site integration. A statistical analysis of the reported bifunctional electrocatalysts is further carried out to reveal the composition-performance relationship and guide further exploration of emerging candidates. Finally, perspectives for developing advanced bifunctional oxygen electrocatalysts and aqueous rechargeable metal-air batteries are proposed.

Strong photoperiod sensitivity is controlled by cooperation and competition among Hd1, Ghd7 and DTH8 in rice heading.

Rice (Oryza sativa) is a short-day (SD) plant originally having strong photoperiod sensitivity (PS), with SDs promoting and long days (LDs) suppressing flowering. Although the evolution of PS in rice has been extensively studied, there are few studies that combine the genetic effects and underlying mechanism of different PS gene combinations with variations in PS. We created a set of isogenic lines among the core PS-flowering genes Hd1, Ghd7 and DTH8 using CRISPR mutagenesis, to systematically dissect their genetic relationships under different day-lengths. We investigated their monogenic, digenic, and trigenic effects on target gene regulation and PS variation. We found that Hd1 and Ghd7 have the primary functions for promoting and repressing flowering, respectively, regardless of day-length. However, under LD conditions, Hd1 promotes Ghd7 expression and is recruited by Ghd7 and/or DTH8 to form repressive complexes that collaboratively suppress the Ehd1-Hd3a/RFT1 pathway to block heading, but under SD conditions Hd1 competes with the complexes to promote Hd3a/RFT1 expression, playing a tradeoff relationship with PS flowering. Natural allelic variations of Hd1, Ghd7 and DTH8 in rice populations have resulted in various PS performances. Our findings reveal that rice PS flowering is controlled by crosstalk of two modules - Hd1-Hd3a/RFT1 in SD conditions and (Hd1/Ghd7/DTH8)-Ehd1-Hd3a/RFT1 in LD conditions - and the divergences of these genes provide the basis for rice adaptation to broad regions.

Can Aqueous Zinc-Air Batteries Work at Sub-Zero Temperatures?

Efficient energy storage at low temperatures starves for competent battery techniques. Herein, inherent advantages of zinc-air batteries on low-temperature electrochemical energy storage are discovered. The electrode reactions are resistive against low temperatures to render feasible working zinc-air batteries under sub-zero temperatures. The relatively reduced ionic conductivity of electrolyte is identified as the main limiting factor, which can be addressed by employing a CsOH-based electrolyte through regulating the solvation structures. Accordingly, 500 cycles with a stable voltage gap of 0.8 V at 5.0 mA cm-2 is achieved at -10 °C. This work reveals the promising potential of zinc-air batteries for low-temperature electrochemical energy storage and inspires advanced battery systems under extreme working conditions.

Arabidopsis Cell Division Cycle 20.1 Is Required for Normal Meiotic Spindle Assembly and Chromosome Segregation.

Cell division requires proper spindle assembly; a surveillance pathway, the spindle assembly checkpoint (SAC), monitors whether the spindle is normal and correctly attached to kinetochores. The SAC proteins regulate mitotic chromosome segregation by affecting CDC20 (Cell Division Cycle 20) function. However, it is unclear whether CDC20 regulates meiotic spindle assembly and proper homolog segregation. Here, we show that the Arabidopsis thaliana CDC20.1 gene is indispensable for meiosis and male fertility. We demonstrate that cdc20.1 meiotic chromosomes align asynchronously and segregate unequally and the metaphase I spindle has aberrant morphology. Comparison of the distribution of meiotic stages at different time points between the wild type and cdc20.1 reveals a delay of meiotic progression from diakinesis to anaphase I. Furthermore, cdc20.1 meiocytes exhibit an abnormal distribution of a histone H3 phosphorylation mark mediated by the Aurora kinase, providing evidence that CDC20.1 regulates Aurora localization for meiotic chromosome segregation. Further evidence that CDC20.1 and Aurora are functionally related was provided by meiosis-specific knockdown of At-Aurora1 expression, resulting in meiotic chromosome segregation defects similar to those of cdc20.1. Taken together, these results suggest a critical role for CDC20.1 in SAC-dependent meiotic chromosome segregation.

Suppression or knockout of SaF/SaM overcomes the Sa-mediated hybrid male sterility in rice.

Hybrids between the indica and japonica subspecies of rice (Oryza sativa) are usually sterile, which hinders utilization of heterosis in the inter-subspecific hybrid breeding. The complex locus Sa comprises two adjacently located genes, SaF and SaM, which interact to cause abortion of pollen grains carrying the japonica allele in japonica-indica hybrids. Here we showed that silencing of SaF or SaM by RNA interference restored male fertility in indica-japonica hybrids with heterozygous Sa. We further used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing to knockout the SaF and SaM alleles, respectively, of an indica rice line to create hybrid-compatible lines. The resultant artificial neutral alleles did not affect pollen viability and other agricultural traits, but did break down the reproductive barrier in the hybrids. We found that some rice lines have natural neutral allele Sa-n, which was compatible with the typical japonica or indica Sa alleles in hybrids. Our results demonstrate that SaF and SaM are required for hybrid male sterility, but are not essential for pollen development. This study provides effective approaches for the generation of hybrid-compatible lines by knocking out the Sa locus or using the natural Sa-n allele to overcome hybrid male sterility in rice breeding. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.

Genetic interactions between diverged alleles of Early heading date 1 (Ehd1) and Heading date 3a (Hd3a)/ RICE FLOWERING LOCUS T1 (RFT1) control differential heading and contribute to regional adaptation in rice (Oryza sativa).

Initiation of flowering, also called heading, in rice (Oryza sativa) is determined by the florigens encoded by Heading date 3a (Hd3a) and RICE FLOWERING LOCUS T1 (RFT1). Early heading date 1 (Ehd1) regulates Hd3a and RFT1. However, different rice varieties have diverged alleles of Ehd1 and Hd3a/RFT1 and their genetic interactions remain largely unclear. Here we generated three segregating populations for different combinations of diverged Ehd1 and Hd3a/RFT1 alleles, and analyzed their genetic interactions between these alleles. We demonstrated that, in an ehd1 mutant background, Hd3a was silenced, but RFT1 was expressed (although at lower levels than in plants with a functional Ehd1) under short-day (SD) and long-day (LD) conditions. We identified a nonfunctional RFT1 allele (rft1); the lines carrying homozygous ehd1 and Hd3a/rft1 failed to induce the floral transition under SD and LD conditions. Like Hd3a, RFT1 also interacted with 14-3-3 proteins, the florigen receptors, but a nonfunctional RFT1 with a crucial E105K mutation failed to interact with 14-3-3 proteins. Furthermore, analyses of sequence variation and geographic distribution suggested that functional RFT1 alleles were selected during rice adaptation to high-latitude regions. Our results demonstrate the important roles of RFT1 in rice flowering and regional adaptation.

Hydrothermal Synthesis of Cancrinite from Coal Gangue for the Immobilization of Sr.

The primary objective of this study is to investigate and develop a rapid and effective method for the immobilization of Sr in the event of a nuclear leakage incident. Coal gangue, an underutilized form of solid waste from the coal industry, can be used as a raw material for curing Sr due to its high content of silica-alumina oxides. In the present study, Sr was successfully solidified in cancrinite synthesized using a hydrothermal method with coal gangue as raw material. A stable cancrinite phase was formed at a relative alkali concentration of more than 6 M. When the Sr/Al(Si) ratio was <1/6, cancrinite was the only stable phase that varied with the hydrothermal temperature and time. When the Sr/Al(Si) ratio increased to 1/2, the cancrinite phase completely disappeared, and a new strontium feldspar phase (SrAl2Si2O8) appeared. PCT leaching experiments showed that when Sr/Al(Si) < 1/6, the Sr leaching rate of Sr-cancrinite samples obtained by hydrothermal synthesis at 180 °C for 24 h was very low.

Efficacy and Safety of Shi Cervical Rotational Manipulation in Patients With Atlantoaxial Joint Subluxation: Protocol for a Randomized Controlled Trial.

BACKGROUND: The clinical diagnosis of atlantoaxial joint subluxation (AJS) in traditional Chinese medicine (TCM) is characterized by an unequal distance between the lateral mass of the atlas and the odontoid process on imaging, resulting in neck pain accompanied by symptoms such as dizziness, headache, and limited cervical mobility. In Shanghai, Shi cervical rotational manipulation (SCRM) is a commonly employed TCM manual therapy for treating this condition. Nevertheless, there is a lack of evidence-based medical information regarding the clinical efficacy and safety of this technique. OBJECTIVE: The principal aim of this study is to evaluate the efficacy and safety of SCRM in patients diagnosed with AJS. METHODS: This study is a prospective randomized controlled clinical trial that will be conducted at a single center and that has a follow-up period of 24 weeks. A total of 96 patients diagnosed with AJS will be recruited from outpatient and inpatient clinics at Shanghai Baoshan Hospital of Integrated Traditional Chinese and Western Medicine. These patients will be randomly assigned to either the experimental group (SCRM) or the comparison group (basic cervical manipulation [BCM]). Treatment sessions consisting of SCRM or BCM will be administered twice a week for a duration of 4 weeks. Clinical monitoring indicators include the presence or absence of clinical symptoms as recorded on a symptom recording form, cervical imaging examination findings using cervical computed tomography, degree of neck pain measured by a visual analog scale (VAS), cervical range of motion assessed through cervical mobility measurement, degree of vertigo evaluated using the Vertigo Symptoms Scale-Chinese Version (VSS-C), and adverse events that may occur during the follow-up period. The time points for data collection and follow-up are baseline and postintervention (weeks 4, 8, 12, 16, 20, and 24). RESULTS: This paper presents an overview of the reasoning and structure of a prospective randomized controlled trial with the objective of investigating the clinical efficacy and safety of SCRM in patients with AJS by assessing improvements in clinical symptoms, neck pain severity, and vertigo severity and evaluating changes in cervical imaging findings. Recruitment was started in March 2023. By the end of May 2024, 76 patients were included in this project. The last follow-up data are predicted to be collected by the end of February 2025. CONCLUSIONS: This investigation will yield dependable evidence regarding the efficacy and safety of SCRM in patients with AJS. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300068510; https://www.chictr.org.cn/showprojEN.html?proj=186883. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/57865.

The ATP-binding cassette transporter OsABCG15 is required for anther development and pollen fertility in rice.

Plant male reproductive development is a complex biological process, but the underlying mechanism is not well understood. Here, we characterized a rice (Oryza sativa L.) male sterile mutant. Based on map-based cloning and sequence analysis, we identified a 1,459-bp deletion in an adenosine triphosphate (ATP)-binding cassette (ABC) transporter gene, OsABCG15, causing abnormal anthers and male sterility. Therefore, we named this mutant osabcg15. Expression analysis showed that OsABCG15 is expressed specifically in developmental anthers from stage 8 (meiosis II stage) to stage 10 (late microspore stage). Two genes CYP704B2 and WDA1, involved in the biosynthesis of very-long-chain fatty acids for the establishment of the anther cuticle and pollen exine, were downregulated in osabcg15 mutant, suggesting that OsABCG15 may play a key function in the processes related to sporopollenin biosynthesis or sporopollenin transfer from tapetal cells to anther locules. Consistently, histological analysis showed that osabcg15 mutants developed obvious abnormality in postmeiotic tapetum degeneration, leading to rapid degredation of young microspores. The results suggest that OsABCG15 plays a critical role in exine formation and pollen development, similar to the homologous gene of AtABCG26 in Arabidopsis. This work is helpful to understand the regulatory network in rice anther development.

Multifunctional GeMnTe2 Synergistically Optimizes Thermoelectric Properties of SnTe-In2Te3 Alloys.

SnTe-In2Te3 alloys ensure excellent electrical properties in the whole temperature region due to the resonant level. Nevertheless, temperature-sensitive resonance states and single phonon scattering restrict further improvement of thermoelectric performance. Consequently, it is anticipated that additional electrically independent scattering sources should be introduced to impede phonon transport. Here, the SnTe-In2Te3-GeMnTe2 alloy is prepared by further solidifying cubic GeMnTe2, which demonstrates multiple modulation effects. The highly redissolved Mn2+ promotes the valence band convergence, enhances the Seebeck coefficient at higher temperature, and balances the possible weakened resonance level effect at higher carrier concentrations, and a high average power factor (1.94 mW m-1 K-2) is realized over the entire temperature range. Additionally, compensatory vacancies, substitutions, and Ge/Mn precipitates are easily constructed with GeMnTe2 alloying, leading to a further reduction in lattice thermal conductivity, which reaches κl ∼ 0.6 W m-1 K-1 at 850 K. Ultimately, a high peak zT of ∼1.25 (850 K) and a zTave of 0.72 (300-850 K) are realized in (SnTe)2.91(In2Te3)0.03(Ge0.5Mn0.5Te)1.2, and the maximum thermoelectric conversion efficiency of ∼2.8% (ΔT ∼ 450 K) is achieved. The present results indicate multiple effects of GeMnTe2 in enhancing the thermoelectric performance of SnTe-In2Te3 alloys.

Cu2Te Incorporation-Induced High Average Thermoelectric Performance in p-Type Bi2Te3 Alloys.

p-Type (Bi, Sb)2Te3 alloys are attractive materials for near-room-temperature thermoelectric applications due to their high atomic masses and large spin-orbit interactions. However, their narrow band gaps originating from spin-orbit interactions lead to bipolar excitation, thereby limiting average thermoelectrics within a local temperature region (300-400 K). Here, we introduce Cu2Te into the Bi0.3Sb1.7Te3 (BST) lattice to implement high thermoelectrics over a wide temperature range. The carrier concentration is synergistically modulated via Cu substitution and the evolution of intrinsic point defects (antisites and vacancies). Furthermore, the chain effect caused by Cu2Te incorporation in BST is reflected in the improvement of the weighted mobility µW, thereby enhancing the power factor in the whole temperature range. Extrinsic and intrinsic defects due to the incorporation of Cu2Te lead to a significant reduction in the lattice thermal conductivity κL, which is further demonstrated by Raman spectroscopy. Combining κL and µW, the quantity factor B increases from 0.5 to 1 with increasing Cu2Te content due to not only the reduction of κL but also a significant improvement in electrical properties. Eventually, a peak figure of merit (zT) of ∼1.15 at 423 K is achieved in BST-Cu2Te samples, and an average figure of merit (zTave) of ∼1.12 (350-500 K) surpasses other excellent p-type Bi2Te3-based thermoelectrics. Such a synergistic effect can facilitate near-room-temperature thermoelectric applications of Bi2Te3-based alloys and provide chances for the technology space in thermoelectrics.

Factors associated with left ventricular diastolic dysfunction in patients with septic shock.

PURPOSE: To investigate risk factors associated with left ventricular diastolic dysfunction (LVDD) of patients with septic shock. MATERIALS AND METHODS: Patients with septic shock concomitant with or without LVDD were retrospectively enrolled and divided into the LVDD group (n = 17) and control without LVDD (n = 85). The clinical and ultrasound data were analyzed. RESULTS: A significant (P < 0.05) difference existed between the two groups in serum creatinine, APACHE II score, serum glucose, triglyceride, BUN, FT4, LAVI, mitral E, average e', E/average e', septal e', septal e'/septal s', E/septal e', lateral s', lateral e', and E/lateral e'. LAVI > 37 mL/m2, septal e' < 7 cm/s (OR 11.04, 95% CI 3.38-36.05), septal e'/septal s' < 0.8 (OR 4.09, 95% CI 1.37-12.25), E/septal e' > 15 (OR 22.86, 95% CI 6.09-85.79), lateral e' < 8 cm/s (OR 9.16, 95% CI 2.70-31.07), E/lateral e' > 13 (OR 52, 95% CI 11.99- 225.55), lateral s' < 10 (OR 3.36, 95% CI 1.13-9.99), average e' > 10, E/average e' > 10 (OR 9.53, 95% CI 2.49-36.46), APACHE II score > 16 (OR 3.33, 95% CI 1.00-11.03), SOFA > 5 (or 3.43, 95% CI 1.11-10.60), BUN > 12 mmol/L (OR 3.37, 95% CI 1.15-9.87), serum creatinine > 146 µmol/L (OR 5.08, 95% CI 1.69-15.23), serum glucose > 8 mmol/L (OR 3.36, 95% CI 1.09-10.40), and triglyceride > 1.8 mmol/L were significant (P < 0.05) risk factors for LVDD. LAVI > 37 ml/m2, lateral e' < 8 cm/s, E/lateral e' > 13, and SOFA > 5 were significant (P < 0.05) independent risk factors for LVDD. ROC curve analysis demonstrated that the cut-off value and AUC were 37.09 mL/m2 and 0.85 for LAVI, 8.00 cm/s and 0.89 for lateral e', 12.86 and 0.82 for E/lateral e', and 5.00 and 0.69 for SOFA, respectively. CONCLUSION: Left atrial volume index, mitral lateral e', E/lateral e', and SOFA score are significant independent risk factors for predicting left ventricular diastolic dysfunction in patients with septic shock.

Methyladenosine Modification in RNAs: From Regulatory Roles to Therapeutic Implications in Cancer.

Methyladenosine modifications are the most abundant RNA modifications, including N6-methyladenosine (m6A), N1-methyladenosine (m1A), and 2'-O-methyladenosine (m6Am). As reversible epigenetic modifications, methyladenosine modifications in eukaryotic RNAs are not invariable. Drastic alterations of m6A are found in a variety of diseases, including cancers. Dynamic changes of m6A modification induced by abnormal methyltransferase, demethylases, and readers can regulate cancer progression via interfering with the splicing, localization, translation, and stability of mRNAs. Meanwhile, m6A, m1A, and m6Am modifications also exert regulatory effects on noncoding RNAs in cancer progression. In this paper, we reviewed recent findings concerning the underlying biomechanism of methyladenosine modifications in oncogenesis and metastasis and discussed the therapeutic potential of methyladenosine modifications in cancer treatments.

Preconstructing Asymmetric Interface in Air Cathodes for High-Performance Rechargeable Zn-Air Batteries.

Rechargeable zinc-air batteries afford great potential toward next-generation sustainable energy storage. Nevertheless, the oxygen redox reactions at the air cathode are highly sluggish in kinetics to induce poor energy efficiency and limited cycling lifespan. Air cathodes with asymmetric configurations significantly promote the electrocatalytic efficiency of the loaded electrocatalysts, whereas rational synthetic methodology to effectively fabricate asymmetric air cathodes remains insufficient. Herein, a strategy of asymmetric interface preconstruction is proposed to fabricate asymmetric air cathodes for high-performance rechargeable zinc-air batteries. Concretely, the asymmetric interface is preconstructed by introducing immiscible organic-water diphases within the air cathode, at which the electrocatalysts are in situ formed to achieve an asymmetric configuration. The as-fabricated asymmetric air cathodes realize high working rates of 50 mA cm-2 , long cycling stability of 3400 cycles at 10 mA cm-2 , and over 100 cycles under harsh conditions of 25 mA cm-2 and 25 mAh cm-2 . Moreover, the asymmetric interface preconstruction strategy is universal to many electrocatalytic systems and can be easily scaled up. This work provides an effective strategy toward advanced asymmetric air cathodes with high electrocatalytic efficiency and significantly promotes the performance of rechargeable zinc-air batteries.

Arabidopsis Novel Microgametophyte Defective Mutant 1 Is Required for Pollen Viability via Influencing Intine Development in Arabidopsis.

The pollen intine layer is necessary for male fertility in flowering plants. However, the mechanisms behind the developmental regulation of intine formation still remain largely unknown. Here, we identified a positive regulator, Arabidopsis novel microgametophyte defective mutant 1 (AtNMDM1), which influences male fertility by regulating intine formation. The AtNMDM1, encoding a pollen nuclei-localized protein, was highly expressed in the pollens at the late anther stages, 10-12. Both the mutations and the knock-down of AtNMDM1 resulted in pollen defects and significantly lowered the seed-setting rates. Genetic transmission analysis indicated that AtNMDM1 is a microgametophyte lethal gene. Calcofluor white staining revealed that abnormal cellulose distribution was present in the aborted pollen. Ultrastructural analyses showed that the abnormal intine rather than the exine led to pollen abortion. We further found, using transcriptome analysis, that cell wall modification was the most highly enriched gene ontology (GO) term used in the category of biological processes. Notably, two categories of genes, Arabinogalactan proteins (AGPs) and pectin methylesterases (PMEs) were greatly reduced, which were associated with pollen intine formation. In addition, we also identified another regulator, AtNMDM2, which interacted with AtNMDM1 in the pollen nuclei. Taken together, we identified a novel regulator, AtNMDM1 that affected cellulose distribution in the intine by regulating intine-related gene expression; furthermore, these results provide insights into the molecular mechanisms of pollen intine development.