Structures and mechanisms of the Arabidopsis auxin transporter PIN3.

The PIN-FORMED (PIN) protein family of auxin transporters mediates polar auxin transport and has crucial roles in plant growth and development1,2. Here we present cryo-electron microscopy structures of PIN3 from Arabidopsis thaliana in the apo state and in complex with its substrate indole-3-acetic acid and the inhibitor N-1-naphthylphthalamic acid (NPA). A. thaliana PIN3 exists as a homodimer, and its transmembrane helices 1, 2 and 7 in the scaffold domain are involved in dimerization. The dimeric PIN3 forms a large, joint extracellular-facing cavity at the dimer interface while each subunit adopts an inward-facing conformation. The structural and functional analyses, along with computational studies, reveal the structural basis for the recognition of indole-3-acetic acid and NPA and elucidate the molecular mechanism of NPA inhibition on PIN-mediated auxin transport. The PIN3 structures support an elevator-like model for the transport of auxin, whereby the transport domains undergo up-down rigid-body motions and the dimerized scaffold domains remain static.

KCTD proteins regulate morphine dependence via heterologous sensitization of adenylyl cyclase 1 in mice.

Heterologous sensitization of adenylyl cyclase (AC) results in elevated cAMP signaling transduction that contributes to drug dependence. Inhibiting cullin3-RING ligases by blocking the neddylation of cullin3 abolishes heterologous sensitization, however, the modulating mechanism remains uncharted. Here, we report an essential role of the potassium channel tetramerization domain (KCTD) protein 2, 5, and 17, especially the dominant isoform KCTD5 in regulating heterologous sensitization of AC1 and morphine dependence via working with cullin3 and the cullin-associated and neddylation-dissociated 1 (CAND1) protein. In cellular models, we observed enhanced association of KCTD5 with Gß and cullin3, along with elevated dissociation of Gß from AC1 as well as of CAND1 from cullin3 in heterologous sensitization of AC1. Given binding of CAND1 inhibits the neddylation of cullin3, we further elucidated that the enhanced interaction of KCTD5 with both Gß and cullin3 promoted the dissociation of CAND1 from cullin3, attenuated the inhibitory effect of CAND1 on cullin3 neddylation, ultimately resulted in heterologous sensitization of AC1. The paraventricular thalamic nucleus (PVT) plays an important role in mediating morphine dependence. Through pharmacological and biochemical approaches, we then demonstrated that KCTD5/cullin3 regulates morphine dependence via modulating heterologous sensitization of AC, likely AC1 in PVT in mice. In summary, the present study revealed the underlying mechanism of heterologous sensitization of AC1 mediated by cullin3 and discovered the role of KCTD proteins in regulating morphine dependence in mice.

Targeting AGTPBP1 inhibits pancreatic cancer progression via regulating microtubules and ERK signaling pathway.

BACKGROUND: AGTPBP1 is a cytosolic carboxypeptidase that cleaves poly-glutamic acids from the C terminus or side chains of α/ß tubulins. Although its dysregulated expression has been linked to the development of non-small cell lung cancer, the specific roles and mechanisms of AGTPBP1 in pancreatic cancer (PC) have yet to be fully understood. In this study, we examined the role of AGTPBP1 on PC in vitro and in vivo. METHODS: Immunohistochemistry was used to examine the expression of AGTPBP1 in PC and non-cancerous tissues. Additionally, we assessed the malignant behaviors of PC cells following siRNA-mediated AGTPBP1 knockdown both in vitro and in vivo. RNA sequencing and bioinformatics analysis were performed to identify the differentially expressed genes regulated by AGTPBP1. RESULTS: We determined that AGTPBP1 was overexpressed in PC tissues and the higher expression of AGTPBP1 was closely related to the location of tumors. AGTPBP1 inhibition can significantly decrease cell progression in vivo and in vitro. Moreover, the knockdown of AGTPBP1 inhibited the expression of ERK1/2, P-ERK1/2, MYLK, and TUBB4B proteins via the ERK signaling pathway. CONCLUSION: Our research indicates that AGTPBP1 may be a putative therapeutic target for PC.

Thermal stress accelerates Arabidopsis thaliana mutation rate.

Mutations are the source of both genetic diversity and mutational load. However, the effects of increasing environmental temperature on plant mutation rates and relative impact on specific mutational classes (e.g., insertion/deletion [indel] vs. single nucleotide variant [SNV]) are unknown. This topic is important because of the poorly defined effects of anthropogenic global temperature rise on biological systems. Here, we show the impact of temperature increase on Arabidopsis thaliana mutation, studying whole genome profiles of mutation accumulation (MA) lineages grown for 11 successive generations at 29°C. Whereas growth of A. thaliana at standard temperature (ST; 23°C) is associated with a mutation rate of 7 × 10-9 base substitutions per site per generation, growth at stressful high temperature (HT; 29°C) is highly mutagenic, increasing the mutation rate to 12 × 10-9 SNV frequency is approximately two- to threefold higher at HT than at ST, and HT-growth causes an ∼19- to 23-fold increase in indel frequency, resulting in a disproportionate increase in indels (vs. SNVs). Most HT-induced indels are 1-2 bp in size and particularly affect homopolymeric or dinucleotide A or T stretch regions of the genome. HT-induced indels occur disproportionately in nucleosome-free regions, suggesting that much HT-induced mutational damage occurs during cell-cycle phases when genomic DNA is packaged into nucleosomes. We conclude that stressful experimental temperature increases accelerate plant mutation rates and particularly accelerate the rate of indel mutation. Increasing environmental temperatures are thus likely to have significant mutagenic consequences for plants growing in the wild and may, in particular, add detrimentally to mutational load.

Silencing of the T-type voltage-gated calcium channel α1 subunit by fungus-mediated RNAi altered the structure of F-actin and caused defective behaviors in Ditylenchus destructor.

BACKGROUND: T-type calcium channels, characterized as low-voltage activated (LVA) calcium channels, play crucial physiological roles across a wide range of tissues, including both the neuronal and nonneuronal systems. Using in situ hybridization and RNA interference (RNAi) techniques in vitro, we previously identified the tissue distribution and physiological function of the T-type calcium channel α1 subunit (DdCα1G) in the plant-parasitic nematode Ditylenchus destructor. METHODS AND RESULTS: To further characterize the functional role of DdCα1G, we employed a combination of immunohistochemistry and fungus-mediated RNAi and found that DdCα1G was clearly distributed in stylet-related tissue, oesophageal gland-related tissue, secretory-excretory duct-related tissue and male spicule-related tissue. Silencing DdCα1G led to impairments in the locomotion, feeding, reproductive ability and protein secretion of nematodes. To confirm the defects in behavior, we used phalloidin staining to examine muscle changes in DdCα1G-RNAi nematodes. Our observations demonstrated that defective behaviors are associated with related muscular atrophy. CONCLUSION: Our findings provide a deeper understanding of the physiological functions of T-type calcium channels in plant-parasitic nematodes. The T-type calcium channel can be considered a promising target for sustainable nematode management practices.

Clarifying the Functional Role of Serotonin in Meloidogyne graminicola Host Plant Parasitism by Immunolocalization and RNA Interference.

Serotonin (5-hydroxytryptamine) is an essential neurotransmitter involved in regulating various behaviors in plant-parasitic nematodes, including locomotion, egg laying, feeding, and mating. However, the functional role of serotonin in root-knot nematode invasion of host plants and the molecular mechanisms underlying feeding behavior remain poorly understood. In this study, we tested the effects of exogenous serotonin and the pharmacological compounds fluoxetine and methiothepin on the feeding behaviors of Meloidogyne graminicola. Our results suggested that M. graminicola possesses an endogenous serotonin signaling pathway and that serotonin plays a crucial role in modulating feeding behaviors in M. graminicola second-stage juveniles. We also identified and cloned the serotonin synthesis enzyme tryptophan hydroxylase (Mg-tph-1) in M. graminicola and investigated the role of endogenous serotonin by generating RNA interference nematodes in Mg-tph-1. Silencing Mg-tph-1 substantially reduced nematode invasion, development, and reproduction. According to the immunostaining results, we speculated that these serotonin immunoreactive cells near the nerve ring in M. graminicola are likely homologous to Caenorhabditis elegans ADFs, NSMs, and RIH serotonergic neurons. Furthermore, we investigated the impact of phytoserotonin on nematode invasion and development in rice by overexpressing OsTDC-3 or supplementing rice plants with tryptamine and found that an increase in phytoserotonin increases nematode pathogenicity. Overall, our study provides insights into the essential role of serotonin in M. graminicola host plant parasitism and proposes that the serotonergic signaling pathway could be a potential target for controlling plant-parasitic nematodes.

Identifying resistance molecules in TiO2 nanoparticle-tolerant strains to facilitate the development of strategies for combating TiO2 nanoparticle pollution.

The severity of environmental pollution caused by TiO2 nanoparticles (nTiO2) is increasing, highlighting the urgent need for the development of strategies to combat nTiO2 pollution. Insights into resistance molecules from nTiO2-tolerant strains may facilitate such development. In this study, we utilized multi-omics, genetic manipulation, physiological and biochemical experiments to identify relevant resistance molecules in two strains (Physarum polycephalum Z259 and T83) tolerated to mixed-phase nTiO2 (MPnTiO2). We discovered that a competing endogenous RNA (ceRNA) network, comprising one long non-coding RNA (lncRNA), four microRNAs, and nine mRNAs, influenced metabolic rearrangement and was associated with significant resistance in these strains. Additionally, we found that the lncRNA in the ceRNAs network and certain small-weight metabolites associated with the ceRNA exhibited notable mitigation effects not only against MPnTiO2 but also against other types of nTiO2 with broad species applicability (they significantly improved the resistance of several non-nTiO2-tolerant cells/organisms in the laboratory and reduced cell damage of non-nTiO2-tolerant cells/organisms in highly suspected nTiO2-polluted areas of the real world). In summary, this study deepens our understanding of nTiO2-tolerant strains, provides valuable insights into resistance molecules in these strains, and facilitates the development of strategies to combat nTiO2 pollution.

Biocontrol activity and potential mechanism of Bacillus cereus G5 against Meloidogyne graminicola.

Root-knot nematodes (Meloidogyne spp.) are highly destructive pests that cause significant yield losses annually. Biological control of nematodes has emerged as a potential alternative in sustainable agriculture. In this study, we originally isolated Bacillus cereus G5 from the rhizosphere soil of rice (Oryza sativa). Treatment with the fermentation supernatant of G5 in vitro demonstrated high toxicity to second-stage juveniles (J2) of Meloidogyne graminicola and remarkably inhibited egg hatching. Moreover, G5 steadily colonized rhizosphere soil and rice seedlings, and exhibited excellent biocontrol efficacy against M. graminicola under greenhouse conditions. Notably, the volatile organic compounds (VOCs) produced by G5 displayed high fumigant activity against M. graminicola. The G5 VOCs efficiently reduced the gall index and nematode population in rice roots, while also promoting rice growth in double-layered pot tests. Additionally, the expression of defense genes involved in the salicylic acid (OsNPR1, OsWRKY45, OsPAL1), jasmonic acid (OsJaMYB, OsAOS2) and ethylene (OsACS1) signalling pathways was significantly upregulated in rice seedlings treated with G5 VOCs. This suggests that G5 VOCs contribute to eliciting plant defense responses. Furthermore, we identified 14 major VOCs produced by G5 using solid-phase micro-extraction gas chromatography and mass spectrometry (SPEM-GC-MS). Notably, allomatrine, morantel, 1-octen-3-ol and 3-methyl-2-butanol displayed strong contact nematicidal activity. Among these, only 1-octen-3-ol demonstrated fumigant activity against J2s of M. graminicola, with an LC50 value of 758.95 mg/L at 24 h. Overall, these results indicated that the B. cereus G5 and its synthetic VOCs possess high potential as biocontrol agents for managing root-knot nematodes.

New Antifungal and Antifeedant Metabolites from Daldinia eschscholtzii Cocultured with Colletotrichum pseudomajus.

The synchronous co-culture of Daldinia eschscholtzii and Colletotrichum pseudomajus produced one new linear polyketide, eschscholin C (1), along with three known compounds (2-4). One new acorane sesquiterpene, coldaldrin A (5), and one new amide derivative, coldaldamide A (6) as the probe for polyketide intermediate capture, and three known compounds (7-9) were isolated from the sequential co-culture of D. eschscholtzii with C. pseudomajus. The structures and absolute configurations of 1, 5 and 6 were established by spectroscopic analysis including 1D, 2D NMR, the calculations of the NMR, and ECD data. Most compounds showed significant antifungal activities against the tea pathogens C. pseudomajus, and Fusarium asiaticum with MICs of 2-8 µg/mL. Compound 4 also showed antifeedant activity against silkworms with feeding deterrence indices of 79% at the concentration of 50 µg/cm2.

Identification of a psychiatric risk gene NISCH at 3p21.1 GWAS locus mediating dendritic spine morphogenesis and cognitive function.

BACKGROUND: Schizophrenia and bipolar disorder (BD) are believed to share clinical symptoms, genetic risk, etiological factors, and pathogenic mechanisms. We previously reported that single nucleotide polymorphisms spanning chromosome 3p21.1 showed significant associations with both schizophrenia and BD, and a risk SNP rs2251219 was in linkage disequilibrium with a human specific Alu polymorphism rs71052682, which showed enhancer effects on transcriptional activities using luciferase reporter assays in U251 and U87MG cells. METHODS: CRISPR/Cas9-directed genome editing, real-time quantitative PCR, and public Hi-C data were utilized to investigate the correlation between the Alu polymorphism rs71052682 and NISCH. Primary neuronal culture, immunofluorescence staining, co-immunoprecipitation, lentiviral vector production, intracranial stereotaxic injection, behavioral assessment, and drug treatment were used to examine the physiological impacts of Nischarin (encoded by NISCH). RESULTS: Deleting the Alu sequence in U251 and U87MG cells reduced mRNA expression of NISCH, the gene locates 180 kb from rs71052682, and Hi-C data in brain tissues confirmed the extensive chromatin contacts. These data suggested that the genetic risk of schizophrenia and BD predicted elevated NISCH expression, which was also consistent with the observed higher NISCH mRNA levels in the brain tissues from psychiatric patients compared with controls. We then found that overexpression of NISCH resulted in a significantly decreased density of mushroom dendritic spines with a simultaneously increased density of thin dendritic spines in primary cultured neurons. Intriguingly, elevated expression of this gene in mice also led to impaired spatial working memory in the Y-maze. Given that Nischarin is the target of anti-hypertensive agents clonidine and tizanidine, which have shown therapeutic effects in patients with schizophrenia and patients with BD in preliminary clinical trials, we demonstrated that treatment with those antihypertensive drugs could reduce NISCH mRNA expression and rescue the impaired working memory in mice. CONCLUSIONS: We identify a psychiatric risk gene NISCH at 3p21.1 GWAS locus influencing dendritic spine morphogenesis and cognitive function, and Nischarin may have potentials for future therapeutic development.

In Situ Confining Citric Acid-Derived Carbon Dots for Full-Color Room-Temperature Phosphorescence.

Room-temperature phosphorescence has received much attention owing to its potential applications in information encryption and bioelectronics. However, the preparation of full-color single-component-derived phosphorescent materials remains a challenge. Herein, a facile in situ confining strategy is proposed to achieve full-color phosphorescent carbon dots (CDs) through rapid microwave-assisted carbonization of citric acid in NaOH. By tuning the mass ratio of citric acid and NaOH, the obtained CDs exhibit tunable phosphorescence wavelengths ranging from 483 to 635 nm and alterable lifetimes from 58 to 389 ms with a synthesis yield of up to 83.7% (>30 g per synthesis). Theoretical calculations and experimental results confirm that the formation of high-density ionic bonds between cations and CDs leads to efficient afterglow emission via the dissociation of CD arrangement, and the evolution of the aggregation state of CDs results in redshifted phosphorescence. These findings provide a strategy for the synthesis of new insights into achieving and manipulating room-temperature phosphorescent CDs, and prospect their applications in labeling and information encryption.

Clan loyalty and COVID-19 diffusion: Evidence from China.

This paper addresses the substantial role of clan loyalty in promoting COVID-19 diffusion in China. Using a city-date panel dataset of observations from 183 cities (prefecture-level and above) in the period of the special long holiday of Chinese New Year in 2020 (January 24-March 1), we find that regions with higher clan loyalty have more COVID-19 cases than regions with lower clan loyalty. A one standard deviation increase in clan loyalty is associated with an 8.1% increase in COVID-19 cases. We further document that clan loyalty drives COVID-19 cases by promoting mass gatherings, exploiting a staggered difference-in-differences (DID) regression based on city community-management policy shocks. Our paper provides novel evidence of one negative public health consequence of clan loyalty, namely, its aggravation of COVID-19 cases.

Novel Antifungal and Antifeedant Metabolites from Penicillium chrysogenum Co-Cultured with Nemania primolutea and Aspergillus fumigatus.

The endophyte Nemania primolutea, inhibited the growth of Penicillium chrysogenum in the coculture system. Four new compounds, nemmolutines A-B (1-2), and penigenumin (3) from N. primolutea, penemin (4) from P. chrysogenum were isolated from the coculture. On the other hand, P. chrysogenum inhibited the Aspergillus fumigatus in the coculture. Induced metabolites (13-16) with monasone naphthoquinone scaffolds including a new one from P. chrysogenum were produced by the coculture of P. chrysogenum, and A. fumigatus. Interesting, cryptic metabolites penicichrins A-B isolated from wild P. chrysogenum induced by host Ziziphus jujuba medium were also found in induced P. chrysogenum cultured in PDB ordinary medium. So the induction of penicichrin production by supplementing with host extract occurred in the fungus P. chrysogenum not the host medium. The productions of penicichrins were the spontaneous metabolism, and the metabolites (13-16) were the culture driven. Compounds 4, 6, 8, 10, 11, 14, and 15 showed significant antifungal activities against the phytopathogen Alternaria alternata with MICS of 1-8 µg/mL, and compounds 7, 9, and 12 indicated significant antifeedant activities against silkworms with feeding deterrence indexes (FDIs) of 92 %, 66 %, and 64 %. The carboxy group in 4-(2-hydroxybutynoxy)benzoic acid derivatives, and xylabisboeins; the hydroxy group in mellein derivatives; and the quinoid in monasone naphthoquinone increased the antifungal activities.

Two Decarestrictine Analogs from the Soil-Derived Fungus Penicillium sp. YUD18003 Associated with Gastrodia elata.

Two new decarestrictine analogs decarestrictine P and penicitone, together with eight known homologous compounds were isolated from the soil fungus from the rhizosphere of Penicillium sp. YUD18003 related to Gastrodia elata. Their different structures include a decanolides decartestridine P and a long-chain polyhydroxyketone penicitone. The structures of new compounds were determined by nuclear magnetic resonance (NMR) spectroscopic analysis and high resolution electrospray ionization mass spectrometry (HR-ESI-MS), while their absolute configurations were determined by spectroscopic methods, DP4+ probability analysis, modified Snatzke's method and electron circular dichroism (ECD) calculations. All compounds were evaluated for antimicrobial activities.

ART1 and putrescine contribute to rice aluminum resistance via OsMYB30 in cell wall modification.

Cell wall is the first physical barrier to aluminum (Al) toxicity. Modification of cell wall properties to change its binding capacity to Al is one of the major strategies for plant Al resistance; nevertheless, how it is regulated in rice remains largely unknown. In this study, we show that exogenous application of putrescines (Put) could significantly restore the Al resistance of art1, a rice mutant lacking the central regulator Al RESISTANCE TRANSCRIPTION FACTOR 1 (ART1), and reduce its Al accumulation particularly in the cell wall of root tips. Based on RNA-sequencing, yeast-one-hybrid and electrophoresis mobility shift assays, we identified an R2R3 MYB transcription factor OsMYB30 as the novel target in both ART1-dependent and Put-promoted Al resistance. Furthermore, transient dual-luciferase assay showed that ART1 directly inhibited the expression of OsMYB30, and in turn repressed Os4CL5-dependent 4-coumaric acid accumulation, hence reducing the Al-binding capacity of cell wall and enhancing Al resistance. Additionally, Put repressed OsMYB30 expression by eliminating Al-induced H2 O2 accumulation, while exogenous H2 O2 promoted OsMYB30 expression. We concluded that ART1 confers Put-promoted Al resistance via repression of OsMYB30-regulated modification of cell wall properties in rice.

Effects of dietary berberine on growth performance, lipid metabolism, antioxidant capacity and lipometabolism-related genes expression of AMPK signaling pathway in juvenile black carp (Mylopharyngodon piceus) fed high-fat diets.

This study aimed to investigate the effects of high-fat diet (HFD) supplemented with berberine on growth, lipid metabolism, antioxidant capacity and lipometabolism-related genes expression of AMPK signaling pathway in juvenile black carp (Mylopharyngodon piceus). Five hundred and forty healthy fish (4.04 ± 0.01 g) were randomly distributed into six groups, and fed six experimental diets: normal-fat diet (NFD, 5% fat), HFD (15% fat), and four HFDs supplemented with graded levels of berberine, respectively. The results showed that, compared with fish fed NFD, HFD had no effects on the growth of fish except for reducing survival rate, whereas HFD caused extensive lipid accumulation, oxidative stress injury and hepatic abnormalities. However, compared with the HFD group, fish fed HFD containing an appropriate berberine (98.26 or 196.21 mg/kg) improved the growth performance, increased hepatic lipid metabolism and antioxidant enzymes activities, and up-regulated the mRNA expression levels of ampk subunits and lipolysis genes such as pparα, cpt-1, acox, atgl and hsl (P < 0.05). Meanwhile, HFD supplemented with an appropriate berberine reduced crude lipid contents in liver and whole-body, decreased serum lipid contents, and ALT and AST activities, and down-regulated the mRNA expression levels of lipogenesis genes such as srebp-1, acc1, gpat, fas and pparγ, and lipid transporter genes such as fatp, fabp and fat/cd36 (P < 0.05). Thus, HFD supplemented with an appropriate berberine could improve growth of black carp, promote lipid metabolism and enhance antioxidant capacity. The lipid-lowering mechanism of berberine might be mediated by activating AMPK pathway, up-regulating lipolysis genes expression, and down-regulating lipogenesis and transport genes expression.

Population dynamics of Meloidogyne graminicola in soil in different types of direct-seeded rice agroecosystems in Hunan Province, China.

The rice root-knot nematode Meloidogyne graminicola is increasingly widely distributed in China and has had a severe incidence in Hunan Province. It is thus necessary to investigate its population dynamics in paddy fields. This study was conducted to ascertain the effect of direct-seeded rice agroecosystems on the population dynamics of M. graminicola and root gall development in rice. The results indicated that the population density of M. graminicola in soil was markedly influenced by the agroecosystem, rainfall and temperature. The population density of M. graminicola J2, and eggs in the soil and root galls, were significantly larger in the dry aerobic rice agroecosystem and in the rain-fed upland agroecosystem than in the lowland double-rice cropping sequence agroecosystem. As it can affect soil moisture rainfall was the key factor affecting the density of nematodes in both the rain-fed upland agroecosystem and the dry aerobic rice agroecosystem. Field flooding was still an effective way to reduce the population density of M. graminicola. In addition, we observed that M. graminicola can lay eggs outside rice roots under laboratory conditions. Therefore, we propose a hypothesis that M. graminicola lays egg masses within roots when the soil moisture is high, but lays eggs outside when the soil moisture is suitable. By clarifying the population dynamics of M. graminicola in different types of direct-seeded rice agroecosystems, this study is conducive to controlling rice root-knot nematodes.

Ethylene signaling modulates Arabidopsis thaliana nitrate metabolism.

MAIN CONCLUSION: Genetic analysis reveals a previously unknown role for ethylene signaling in regulating Arabidopsis thaliana nitrogen metabolism. Nitrogen (N) is essential for plant growth, and assimilation of soil nitrate (NO3-) and ammonium ions is an important route of N acquisition. Although N import and assimilation are subject to multiple regulatory inputs, the extent to which ethylene signaling contributes to this regulation remains poorly understood. Here, our analysis of Arabidopsis thaliana ethylene signaling mutants advances that understanding. We show that the loss of CTR1 function ctr1-1 mutation confers resistance to the toxic effects of the NO3- analogue chlorate (ClO3-), and reduces the activity of the nitrate reductase (NR) enzyme of NO3- assimilation. Our further analysis indicates that the lack of the downstream EIN2 component (conferred by novel ein2 mutations) suppresses the effect of ctr1-1, restoring ClO3- sensitivity and NR activity to normal. Collectively, our observations indicate an important role for ethylene signaling in regulating Arabidopsis thaliana NO3- metabolism. We conclude that ethylene signaling enables environmentally responsive coordination of plant growth and N metabolism.

A novel kinase subverts aluminium resistance by boosting ornithine decarboxylase-dependent putrescine biosynthesis.

Rice, as one of the most aluminium (Al)-resistant cereal crops, has developed more complicated Al resistance mechanisms than others. By using forward genetic screening from a rice ethyl methanesulfonate mutant library, we obtained a mutant showing specifically high sensitivity to Al. Through MutMap analysis followed by a complementation test, we identified the causal gene, Al-related Protein Kinase (ArPK) for Al-sensitivity. ArPK expression was induced by a relatively longer exposure to high Al concentration in the roots. The result of RNA-sequencing indicated the functional disorder in arginine metabolism pathway with downregulation of N-acetylornithine deacetylase (NAOD) expression and upregulation of Ornithine decarboxylase1 (ODC1) expression in arpk mutant. Al specifically and rapidly upregulated ODC1 expression and causes overaccumulation of putrescine (Put), whereas the ODC inhibitor difluoromethylornithine reverted Al-sensitive phenotype of arpk, suggesting that overaccumulation of endogenous Put might be harmful for root growth, and that ArPK seems to act as an endogenous inhibitor of ODC1 action to maintain suitable endogenous Put level under Al treatment. Overall, we identified ArPK and its putative repressive role in controlling a novel ODC-dependent Put biosynthesis pathway specifically affecting rice Al resistance, thus enriching the fundamental understanding of plant Al resistance.