Rbm46 inhibits reactive oxygen species in mouse embryonic stem cells through modulating BNIP3-mediated mitophagy.

Embryonic stem cells (ESCs) exhibit a metabolic preference for glycolysis over oxidative phosphorylation to meet their substantial adenosine triphosphate (ATP) demands during self-renewal. This metabolic choice inherently maintains low mitochondrial activity and minimal reactive oxygen species (ROS) generation. Nonetheless, the intricate molecular mechanisms governing the restraint of ROS production and the mitigation of cellular damage remain incompletely elucidated. In this study, we reveal the pivotal role of RNA-binding motif protein 46 (RBM46) in ESCs, acting as a direct post transcriptional regulator of ROS levels by modulating BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (Bnip3) mRNA expression. Rbm46 knockout lead to diminished mitochondrial autophagy, culminating in elevated ROS within ESCs, disrupting the delicate balance required for healthy self-renewal. These findings provide insights into a novel mechanism governing ROS regulation in ESCs.

Phosphorylated viral protein evades plant immunity through interfering the function of RNA-binding protein.

Successful pathogen infection in plant depends on a proper interaction between the invading pathogen and its host. Post-translational modification (PTM) plays critical role(s) in plant-pathogen interaction. However, how PTM of viral protein regulates plant immunity remains poorly understood. Here, we found that S162 and S165 of Chinese wheat mosaic virus (CWMV) cysteine-rich protein (CRP) are phosphorylated by SAPK7 and play key roles in CWMV infection. Furthermore, the phosphorylation-mimic mutant of CRP (CRPS162/165D) but not the non-phosphorylatable mutant of CRP (CRPS162/165A) interacts with RNA-binding protein UBP1-associated protein 2C (TaUBA2C). Silencing of TaUBA2C expression in wheat plants enhanced CWMV infection. In contrast, overexpression of TaUBA2C in wheat plants inhibited CWMV infection. TaUBA2C inhibits CWMV infection through recruiting the pre-mRNA of TaNPR1, TaPR1 and TaRBOHD to induce cell death and H2O2 production. This effect can be supressed by CRPS162/165D through changing TaUBA2C chromatin-bound status and attenuating it's the RNA- or DNA-binding activities. Taken together, our findings provide new knowledge on how CRP phosphorylation affects CWMV infection as well as the arms race between virus and wheat plants.

Histone demethylase PHF8 facilitates the development of chronic myeloid leukaemia by directly targeting BCR::ABL1.

Although tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of chronic myeloid leukaemia (CML), TKI resistance remains a major challenge. Here, we demonstrated that plant homeodomain finger protein 8 (PHF8), a histone demethylase was aberrantly enriched in CML samples compared to healthy controls. PHF8 inhibited CML cell differentiation and promoted CML cell proliferation. Furthermore, the proliferation-inhibited function of PHF8-knockdown have stronger effect on imatinib mesylate (IM)-resistant CML cells. Mechanistically, we identified that PHF8 as a transcriptional modulator interacted with the promoter of the BCR::ABL1 fusion gene and alters the methylation levels of H3K9me1, H3K9me2 and H3K27me1, thereby promoting BCR::ABL1 transcription. Overall, our study suggests that targeting PHF8, which directly regulates BCR::ABL1 expression, is a useful therapeutic approach for CML.

ß-Catenin-treated peptides effectively inhibit the proliferation of colorectal cancer.

To verify the inhibitory mechanism of ß-catenin-designed peptides in colorectal cancer(CRC) tumors, the following experiments were performed. In vitro colony formation, Transwell assays, and flow cytometry were performed to assess the biological effects of designed peptides (F18KD, F20A4-7k, F20A4-10k, and F20A3-9k + F20A4-10k + F20A5-9k) in HT-29 cells. In vivo xenograft experiments were performed and treated with peptides. Next, tumors were subjected to Hematoxylin and eosin staining (HE), immunohistochemical, and terminal deoxynucleotidyl transferase dUTP nick end labeling staining assays to evaluate the inhibitory effect of peptides on tumors. ß-Catenin levels were quantified via western blotting (WB) and quantitative real-time polymerase chain reaction, and ß-catenin was located using confocal laser scanning microscopy. T-cell factor-4 (TCF-4), C-myc, and CCND1 levels were quantified via WB. Results were obtained as following. First, the peptides reduced viability, migration, and invasion; promoted apoptosis; and stabilized the S phase of HT-29 cells. Second, peptides suppressed tumor growth and downregulated the expression of CD34, vascular endothelial growth factor, and ß-catenin in tumors. Furthermore, we found that peptides downregulated ß-catenin expression in both the cytoplasm and nucleus; TCF-4, C-myc, and CCND1 expression was also downregulated. Notably, ß-catenin-targeting peptides had a better inhibitory effect on CRC than non-ß-catenin-target peptides, and a combination of peptides exerted a more potent inhibitory effect on CRC than single peptides. It suggested that ß-Catenin-targeting peptides promote apoptosis in CRC tumors by inhibiting activation of the Wnt/ß-catenin pathway.

Functional analysis of the OsNPF4.5 nitrate transporter reveals a conserved mycorrhizal pathway of nitrogen acquisition in plants.

Low availability of nitrogen (N) is often a major limiting factor to crop yield in most nutrient-poor soils. Arbuscular mycorrhizal (AM) fungi are beneficial symbionts of most land plants that enhance plant nutrient uptake, particularly of phosphate. A growing number of reports point to the substantially increased N accumulation in many mycorrhizal plants; however, the contribution of AM symbiosis to plant N nutrition and the mechanisms underlying the AM-mediated N acquisition are still in the early stages of being understood. Here, we report that inoculation with AM fungus Rhizophagus irregularis remarkably promoted rice (Oryza sativa) growth and N acquisition, and about 42% of the overall N acquired by rice roots could be delivered via the symbiotic route under N-NO3- supply condition. Mycorrhizal colonization strongly induced expression of the putative nitrate transporter gene OsNPF4.5 in rice roots, and its orthologs ZmNPF4.5 in Zea mays and SbNPF4.5 in Sorghum bicolor OsNPF4.5 is exclusively expressed in the cells containing arbuscules and displayed a low-affinity NO3- transport activity when expressed in Xenopus laevis oocytes. Moreover, knockout of OsNPF4.5 resulted in a 45% decrease in symbiotic N uptake and a significant reduction in arbuscule incidence when NO3- was supplied as an N source. Based on our results, we propose that the NPF4.5 plays a key role in mycorrhizal NO3- acquisition, a symbiotic N uptake route that might be highly conserved in gramineous species.

Genome-Wide Identification and Analysis of the ABCF Gene Family in Triticum aestivum.

The ATP-binding cassette (ABC) superfamily of proteins is a group of evolutionarily conserved proteins. The ABCF subfamily is involved in ribosomal synthesis, antibiotic resistance, and transcriptional regulation. However, few studies have investigated the role of ABCF in wheat (Triticum aestivum) immunity. Here, we identified 18 TaABCFs and classified them into four categories based on their domain characteristics. Functional similarity between Arabidopsis and wheat ABCF genes was predicted using phylogenetic analysis. A comprehensive genome-wide analysis of gene structure, protein motifs, chromosomal location, and cis-acting elements was also performed. Tissue-specific analysis and expression profiling under temperature, hormonal, and viral stresses were performed using real-time quantitative reverse transcription polymerase chain reaction after randomly selecting one gene from each group. The results revealed that all TaABCF genes had the highest expression at 25 °C and responded to methyl jasmonate induction. Notably, TaABCF2 was highly expressed in all tissues except the roots, and silencing it significantly increased the accumulation of Chinese wheat mosaic virus or wheat yellow mosaic virus in wheat leaves. These results indicated that TaABCF may function in response to viral infection, laying the foundation for further studies on the mechanisms of this protein family in plant defence.

Health risk study of cadmium, chromium, lead and arsenic in reservoir water of Changzhou, China.

Accurately assessing the health risks of human exposure to heavy metals via water is of great importance for performing targeted health risk prevention measures. To better understand the concentration characteristics and potential harm to human health of cadmium, chromium, lead and arsenic in the main drinking water-type reservoirs of Changzhou city, we collected samples from the Haidi Reservoir, Dongjin Reservoir, Xinfushan Reservoir, Maodong Reservoir and Xiangyang Reservoir of Changzhou in the summer of 2019. The results showed that the daily average comprehensive exposure level of metals was much lower than the provisional tolerated daily intake (PTDI), i.e., Cd: 1 µg kg-1 d-1; Cr: 3 µg kg-1 d-1; Pb: 3.57 µg kg-1 d-1; and As: 2.14 µg kg-1 d-1. The comprehensive non-carcinogenic risk levels of four metals under water-drinking exposure and water-skin exposure routes ranged from 4.68E - 3 to 1.69E - 1, and the carcinogenic risk ranged from 2.09E - 5 to 7.30E - 5, which were all at acceptable risk levels. Although lead and chromium were present at acceptable health risk levels, they still represented the main pollutants of potential health risk in the local water environment from a non-carcinogenic or carcinogenic perspective, and they should be listed as the primary targets for water environmental risk management.

The tRNA-like small noncoding RNA mascRNA promotes global protein translation.

mascRNA is a small cytoplasmic RNA derived from the lncRNA MALAT1. After being processed by the tRNA processing enzymes RNase P and RNase Z, mascRNA undergoes CCA addition like tRNAs and folds into a tRNA-like cloverleaf structure. While MALAT1 functions in multiple cellular processes, the role of mascRNA was largely unknown. Here, we show that mascRNA binds directly to the multi-tRNA synthetase complex (MSC) component glutaminyl-tRNA synthetase (QARS). mascRNA promotes global protein translation and cell proliferation by positively regulating QARS protein levels. Our results uncover a role of mascRNA that is independent of MALAT1, but could be part of the molecular mechanism of MALAT1's function in cancer, and provide a paradigm for understanding tRNA-like structures in mammalian cells.

Molecular Characterization of a New Tetrodotoxin-Binding Protein, Peroxiredoxin-1, from Takifugu bimaculatus.

Pufferfish are considered a culinary delicacy but require careful preparation to avoid ingestion of the highly toxic tetrodotoxin (TTX), which accumulates in certain tissues. In this study, the tissue distribution of peroxiredoxin-1 from Takifugu bimaculatus was investigated. The peroxiredoxin-1 protein was obtained by in vitro recombinant expression and purification. The recombinant protein had a strong ability to scavenge hydroxyl radicals, protect superhelical DNA plasmids from oxidative damage, and protect L929 cells from H2O2 toxicity through in vitro antioxidant activity. In addition, we verified its ability to bind to tetrodotoxin using surface plasmon resonance techniques. Further, recombinant proteins were found to facilitate the entry of tetrodotoxin into cells. Through these analyses, we identified, for the first time, peroxiredoxin-1 protein from Takifugu bimaculatus as a potential novel tetrodotoxin-binding protein. Our findings provide a basis for further exploration of the application of peroxiredoxin-1 protein and the molecular mechanisms of tetrodotoxin enrichment in pufferfish.

Quality assessment of Succus Bambusae oral liquids based on gas chromatography/mass spectrometry fingerprints and chemometrics.

RATIONALE: Succus Bambusae is consumed as a kind of herbal medicine and natural beverage in China. However, the current quality standards for Succus Bambusae are low and lack safety indicators, which makes it difficult to effectively guarantee its quality. Therefore, it is of great significance to study the identification and quality control technology for the product. METHODS: We have developed a set of qualitative and quantitative methods based on gas chromatography/mass spectrometry (GC/MS) for the analysis of volatile components in Succus Bambusae oral liquid (SBOL). Combining GC/MS fingerprint analysis and related chemometrics algorithms, with similarity evaluation, Hotelling T2 and distance to Model X (DModX) as criteria, the quality consistency of different batches was evaluated, and SBOL samples from different manufacturers were differentiated. RESULTS: Twenty-nine volatile components were preliminarily identified from 40 batches of SBOL samples from six manufacturers, and six Q-markers (Quality Markers) for the SBOLs were discussed and determined using GC/MS. The products from different manufacturers were distinguished using chemometrics. CONCLUSIONS: The results showed that the quality of the SBOL samples from different batches and different manufacturers fluctuated greatly, which suggested that research into the raw materials and manufacturing techniques should be strengthened to improve the quality of SBOL and ensure its quality consistency.

Transverse and longitudinal coupling of LSPPs in isolated triangular Al-SiO2-Al hybrid nanoplates for generation of local electromagnetic fields with enhanced intensity and increased decay time.

Achieving a large enhancement of local electromagnetic fields in the ultraviolet waveband is desirable for some applications such as surface-enhanced Raman scattering and surface-enhanced fluorescence. In addition, it is more significant for some applications such as plasmon-enhanced harmonic generation to enhance the intensity of local electromagnetic fields and increase their decay time at the same time. In this paper, using the finite-difference time-domain method, we numerically demonstrate that using the linearly polarized light with a wavelength of 325 nm as the illumination light, an isolated triangular Al-SiO2-Al hybrid nanoplate with optimized geometric parameters can produce a local electric field enhanced by a factor of about 108 at one of its top apexes, and produce two local electric fields enhanced by a factor of about 150 at two transverse dielectric/metal interfaces of one of its longitudinal side edges. Moreover, we also numerically demonstrate that the decay time of enhanced local electric fields produced by the isolated triangular Al-SiO2-Al hybrid nanoplate is about 1.6 times as large as that of enhanced local electric fields produced by an isolated triangular Al nanoplate. These unique properties of the isolated triangular Al-SiO2-Al hybrid nanoplate arise because of both the transverse coupling and the longitudinal coupling of localized surface plasmon polaritons in this structure. Our findings make triangular Al-SiO2-Al hybrid nanoplates very promising for application in many fields such as surface-enhanced Raman scattering and plasmon-enhanced harmonic generation.

Multi-Omics Analysis of Gene and Protein Candidates Possibly Related to Tetrodotoxin Accumulation in the Skin of Takifugu flavidus.

Pufferfish is increasingly regarded by many as a delicacy. However, the tetrodotoxin (TTX) that accumulates in its body can be lethal upon consumption by humans. TTX is known to mainly accumulate in pufferfish skin, but the accumulation mechanisms are poorly understood. In this study, we aimed to explore the possible mechanism of TTX accumulation in the skin of the pufferfish Takifugu flavidus following treatment with TTX. Through liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, we detected 37.3% of toxin accumulated in the skin at the end of the rearing period (168 h). Transcriptome and proteome analyses revealed the mechanism and pathways of TTX accumulation in the skin of T. flavidus in detail. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes analyses strongly suggest that cardiac muscle contraction and adrenergic signaling in cardiomyocyte pathways play an important role in TTX accumulation. Moreover, some upregulated and downregulated genes, which were determined via RNA-Seq, were verified with qPCR analysis. This study is the first to use multi-omics profiling data to identify novel regulatory network mechanisms of TTX accumulation in the skin of pufferfish.

[Research progress on chemical constituents and quality control methods of Succus Bambusae].

Through the investigation of a large number of both domestic and overseas literatures and related quality standards, chemical compositions, quality evaluation system and quality control methods of Succus Bambusae were systematic summarized in this study. There were abundant chemical constituents in Succus Bambusae, mainly including volatile ingredients, amino acids, flavonoids, trace elements and vitamins, with high medicinal and edible value. The quality control methods involved traditional morphological identification, spectroscopy, chromatography and other techniques. However, the current quality standards of Succus Bambusae are relatively low, lacking safety indicators, and cannot effectively ensure its quality, seriously affecting the safety and effectiveness of its clinical use. Therefore, it is particularly important to establish a set of highly sensitive and specific quality evaluation system for Succus Bambusae. In this paper, the current research status of the chemical compositions and quality standards of Succus Bambusae were reviewed, with the purpose of providing a basis for further improvement of its quality evaluation system.

Function of NHX-type transporters in improving rice tolerance to aluminum stress and soil acidity.

MAIN CONCLUSION: In this study, we show that ectopic expression of either HtNHX1 or HtNHX2, from Helianthus tuberosus plant (located at vacuolar and endosome membranes, respectively), in rice plants could enhance its tolerance to aluminum (Al3+) stress and soil acidity. Plant sodium (potassium)/proton (Na+(K+)/H+ antiporters of the NHX family have been extensively characterized as they are related to the enhancement of salt tolerance. However, no previous study has reported NHX transporter functions in plant tolerance to Al3+ toxicity. In this study, we demonstrate their role as a component of the Al3+ stress tolerance mechanism. We show that the ectopic expression of either HtNHX1 or HtNHX2 , from Helianthus tuberosus plant, in rice (located at vacuole and endosome, respectively) could also enhance rice tolerance to Al3+ stress and soil acidity. Expression of either HtNHX1 or HtNHX2 reduced the inhibitory effect of Al3+ on the rice root elongation rate; both genes were reported to be equally effective in improvement of stress conditions. Expression of HtNHX1 enhanced Al3+-trigged-secretion of citrate acids, rhizosphere acidification, and also reduced K+ efflux from root tissues. In contrast, expression of HtNHX2 prevented Al3+-trigged-decrease of H+ influx into root tissues. Al3+-induced damage of the cell wall extensibility at the root tips was impaired by either HtNHX1 or HtNHX2. Co-expression of HtNHX1 and HtNHX2 further improved rice growth, particularly under the Al3+ stress conditions. The results demonstrate that HtNHX1 and HtNHX2 improved rice tolerance to Al3+ via different mechanisms by altering the K+ and H+ fluxes and the cell wall structure.

Plant nitrogen uptake and assimilation: regulation of cellular pH homeostasis.

The enzymatic controlled metabolic processes in cells occur at their optimized pH ranges, therefore cellular pH homeostasis is fundamental for life. In plants, the nitrogen (N) source for uptake and assimilation, mainly in the forms of nitrate (NO3-) and ammonium (NH4+) quantitatively dominates the anion and cation equilibrium and the pH balance in cells. Here we review ionic and pH homeostasis in plant cells and regulation by N source from the rhizosphere to extra- and intracellular pH regulation for short- and long-distance N distribution and during N assimilation. In the process of N transport across membranes for uptake and compartmentation, both proton pumps and proton-coupled N transporters are essential, and their proton-binding sites may sense changes of apoplastic or intracellular pH. In addition, during N assimilation, carbon skeletons are required to synthesize amino acids, thus the combination of NO3- or NH4+ transport and assimilation results in different net charge and numbers of protons in plant cells. Efficient maintenance of N-controlled cellular pH homeostasis may improve N uptake and use efficiency, as well as enhance the resistance to abiotic stresses.

Ultra-large local field enhancement effect of isolated thick triangular silver nanoplates on a silicon substrate in the green waveband.

The local field enhancement in plasmonic nanostructures is vital for surface enhanced Raman scattering (SERS). However, it remains a challenge to achieve a large local field enhancement at an illumination wavelength in the green waveband. Here we report on an ultra-large local field enhancement effect of isolated thick triangular silver nanoplates (ITTSNPs) on a silicon substrate at an illumination wavelength in the green waveband. We show that when the thickness of the ITTSNP is larger than a critical thickness depending on the illumination wavelength, a large local field enhancement with an enhancement factor (EF) greater than 350 can be achieved at an illumination wavelength in the green waveband, which is due to the excitation of strong localized surface plasmon polaritons only at three top apexes of the ITTSNP. Furthermore, we experimentally demonstrate that at an excitation wavelength of 514.5 nm, the average SERS EF of the ITTSNPs can exceed ${{10}^{11}}$1011, and the sensitivity for the detection of Rhodamine 6 G molecules can reach ${{10}^{ - 12}}\;{\rm M}$10-12M.

Rice OsHAK16 functions in potassium uptake and translocation in shoot, maintaining potassium homeostasis and salt tolerance.

MAIN CONCLUSION: OsHAK16 mediates K uptake and root-to-shoot translocation in a broad range of external K concentrations, thereby contributing to the maintenance of K homeostasis and salt tolerance in the rice shoot. The HAK/KUP/KT transporters have been widely associated with potassium (K) transport across membranes in both microbes and plants. Here, we report the physiological function of OsHAK16, a member belonging to the HAK/KUP/KT family in rice (Oryza sativa L.). Transcriptional expression of OsHAK16 was up-regulated by K deficiency or salt stress. OsHAK16 is localized at the plasma membrane. OsHAK16 knockout (KO) dramatically reduced root K net uptake rate and growth at both 0.1 mM and 1 mM K supplies, while OsHAK16 overexpression (OX) increased total K uptake and growth only at 0.1 mM K level. OsHAK16-KO decreased the rate of rubidium (Rb) uptake and translocation compared to WT at both 0.2 mM and 1 mM Rb levels. OsHAK16 disruption decreased while its overexpression increased K concentration in root slightly but in shoot remarkably. The relative distribution of total K between shoot and root decreased by 30% in OsHAK16-KO lines and increased by 30% in its OX lines compared to WT. OsHAK16-KO diminished K uptake and K/Na ratio, while OsHAK16-OX improved K uptake and translocation from root to shoot, resulting in increased sensitivity and tolerance to salt stress, respectively. Expression of OsHAK16 enhanced the growth of high salt-sensitive yeast mutant by increasing its K but no Na content. Taking all these together, we conclude that OsHAK16 plays crucial roles in maintaining K homeostasis and salt tolerance in rice shoot.

PGC-1ß cooperating with FOXA2 inhibits proliferation and migration of breast cancer cells.

BACKGROUND: Breast cancer is one of the most common malignancy among females from the worldwide cancer incidence statistics. Peroxisome gamma coactivator-1ß (PGC-1ß) has long been identified to be involved in this type of tumorigenesis. However, the mechanisms of PGC-1ß in human breast cancer have not been fully understood and the function requires to be further elucidated. METHODS: mRNA and protein expression of PGC-1ß and FOXA2 in breast cancer tissues and cell lines were determined by qRT-PCR and Western Blotting, respectively. To further visualize the expression and localization of PGC-1ß and FOXA2, immunochemistry and immunofluorescence staining methods were employed. The effect of PGC-1ß and FOXA2 on cell proliferation and migration were evaluated by CCK8, clone formation, transwell and wound-healing assays, which has been done either with stable PGC-1ß knockdown or FOXA2 overexpression in vitro. Xenografts model of nude mice were used to evaluate tumor growth in vivo. In addition, proteins expression of the PI3K-AKT-mTOR signaling pathway involved in the regulation of breast cancer were detected by Western Blotting. RESULTS: Our results showed that PGC-1ß was upregulated and FOXA2 was downregulated in breast cancer tissues and cell lines. These two proteins can be interacted with each other to form the complex. Also, we found the combination of PGC-1ß interference with FOXA2 overexpression significantly inhibited cell proliferation and migration in vitro as well as tumor growth in vivo. We further identified that PGC-1ß and FOXA2 strongly correlated with the PI3K-AKT-mTOR signaling pathway, and they exerted their biological functions by activating this pathway. CONCLUSIONS: We demonstrated that downregulation of PGC-1ß combined with overexpression of FOXA2 obviously inhibited the function of breast cancer cells through regulating the PI3K-AKT-mTOR pathway.

Combined effect of titanium dioxide nanoparticles and glucose on the cardiovascular system in young rats after oral administration.

Titanium dioxide nanoparticles (TiO2 NPs) have already been used as food additive in various products and are usually consumed with a considerable amount of sugar. Oral consumption of TiO2 NPs poses concerning health risks; however, research on the combined effect of ingested TiO2 NPs and glucose is limited. We examined young Sprague-Dawley rats administrated TiO2 NPs orally at doses of 0, 2, 10 and 50 mg/kg body weight per day with and without 1.8 g/kg body weight glucose for 30 and 90 days. Heart rate, systolic and diastolic blood pressure, blood biochemical parameters and histopathology of cardiac tissues was assessed to quantify cardiovascular damage. The results showed that oral exposure to TiO2 NPs and high doses of glucose both could induce cardiovascular injuries. The toxic effects were dose-, time- and gender-dependent. The interaction effects between oral-exposed TiO2 NPs and glucose existed and revealed to be antagonism in most of the biological parameters. However, toxic effects of the high-dose glucose seemed to be more severe than TiO2 NPs and the interaction of TiO2 NPs with glucose. These results suggest that it may be more important to control the sugar intake than TiO2 NPs for protecting the health of TiO2 NP consumers.

Two NHX-type transporters from Helianthus tuberosus improve the tolerance of rice to salinity and nutrient deficiency stress.

The NHX-type cation/H+ transporters in plants have been shown to mediate Na+ (K+ )/H+ exchange for salinity tolerance and K+ homoeostasis. In this study, we identified and characterized two NHX homologues, HtNHX1 and HtNHX2 from an infertile and salinity tolerant species Helianthus tuberosus (cv. Nanyu No. 1). HtNHX1 and HtNHX2 share identical 5'- and 3'-UTR and coding regions, except for a 342-bp segment encoding 114 amino acids (L272 to Q385 ) which is absent in HtNHX2. Both hydroponics and soil culture experiments showed that the expression of HtNHX1 or HtNHX2 improved the rice tolerance to salinity. Expression of HtNHX2, but not HtNHX1, increased rice grain yield, harvest index, total nutrient uptake under K+ -limited salt-stress or general nutrient deficiency conditions. The results provide a novel insight into NHX function in plant mineral nutrition.