A teosinte-derived allele of ZmSC improves salt tolerance in maize.

Maize, a salt-sensitive crop, frequently suffers severe yield losses due to soil salinization. Enhancing salt tolerance in maize is crucial for maintaining yield stability. To address this, we developed an introgression line (IL76) through introgressive hybridization between maize wild relatives Zea perennis, Tripsacum dactyloides, and inbred Zheng58, utilizing the tri-species hybrid MTP as a genetic bridge. Previously, genetic variation analysis identified a polymorphic marker on Zm00001eb244520 (designated as ZmSC), which encodes a vesicle-sorting protein described as a salt-tolerant protein in the NCBI database. To characterize the identified polymorphic marker, we employed gene cloning and homologous cloning techniques. Gene cloning analysis revealed a non-synonymous mutation at the 1847th base of ZmSCIL76 , where a guanine-to-cytosine substitution resulted in the mutation of serine to threonine at the 119th amino acid sequence (using ZmSCZ58 as the reference sequence). Moreover, homologous cloning demonstrated that the variation site derived from Z. perennis. Functional analyses showed that transgenic Arabidopsis lines overexpressing ZmSCZ58 exhibited significant reductions in leaf number, root length, and pod number, alongside suppression of the expression of genes in the SOS and CDPK pathways associated with Ca2+ signaling. Similarly, fission yeast strains expressing ZmSCZ58 displayed inhibited growth. In contrast, the ZmSCIL76 allele from Z. perennis alleviated these negative effects in both Arabidopsis and yeast, with the lines overexpressing ZmSCIL76 exhibiting significantly higher abscisic acid (ABA) content compared to those overexpressing ZmSCZ58 . Our findings suggest that ZmSC negatively regulates salt tolerance in maize by suppressing downstream gene expression associated with Ca2+ signaling in the CDPK and SOS pathways. The ZmSCIL76 allele from Z. perennis, however, can mitigate this negative regulatory effect. These results provide valuable insights and genetic resources for future maize salt tolerance breeding programs.

Epidemic characteristics of local HIV-2 transmission across Hunan province, China.

OBJECTIVE: To elucidate the epidemiological features of HIV-2 in Hunan Province, China, utilizing sequence analysis. METHODS: Thirteen individuals diagnosed with HIV-2 infection in Hunan Province, China, from 2017 to 2023 were included in this study. Amplification of HIV-2 env and pol regions was conducted, followed by Sanger sequencing. Phylogenetic and molecular transmission network analyses were performed to delineate molecular features and transmission dynamics. RESULTS: All 14 individuals contracted HIV-2 through heterosexual intercourse, comprising 7 males and 7 females, with a median age of 58 years. Among them, three couples (HN001 and HN013, HN010 and HN011, HN008 and HN009) were identified, along with commercial sexual activity engagement reported for subject HN004. Notably, subjects HN001, HN003, HN008, and HN010 engaged in commercial sexual activities at the same location as subject HN004. Phylogenetic analysis of the pol gene revealed close proximity of sequences from all subjects to reference sequences from Gambia (Sub-type A). Employing a genetic distance threshold of 1.5 %, eight out of the 14 subjects formed a molecular transmission network, with HN002 and HN004 identified as central nodes. CONCLUSION: From 2017 to 2023, all HIV-2-infected individuals in Hunan Province, China, acquired the virus through identifiable routes, indicating transmission of similar HIV-2 strains among them.

Genome dosage alteration caused by chromosome pyramiding and shuffling effects on karyotypic heterogeneity, reproductive diversity, and phenotypic variation in Zea-Tripsacum allopolyploids.

KEY MESSAGE: We developed an array of Zea-Tripsacum tri-hybrid allopolyploids with multiple ploidies. We unveiled that changes in genome dosage due to the chromosomes pyramiding and shuffling of three species effects karyotypic heterogeneity, reproductive diversity, and phenotypic variation in Zea-Tripsacum allopolyploids. Polyploidy, or whole genome duplication, has played a major role in evolution and speciation. The genomic consequences of polyploidy have been extensively studied in many plants; however, the extent of chromosomal variation, genome dosage, phenotypic diversity, and heterosis in allopolyploids derived from multiple species remains largely unknown. To address this question, we synthesized an allohexaploid involving Zea mays, Tripsacum dactyloides, and Z. perennis by chromosomal pyramiding. Subsequently, an allooctoploid and an allopentaploid were obtained by hybridization of the allohexaploid with Z. perennis. Moreover, we constructed three populations with different ploidy by chromosomal shuffling (allopentaploid × Z. perennis, allohexaploid × Z. perennis, and allooctoploid × Z. perennis). We have observed 3 types of sexual reproductive modes and 2 types of asexual reproduction modes in the tri-species hybrids, including 2n gamete fusion (2n + n), haploid gamete fusion (n + n), polyspermy fertilization (n + n + n) or 2n gamete fusion (n + 2n), haploid gametophyte apomixis, and asexual reproduction. The tri-hybrids library presents extremely rich karyotype heterogeneity. Chromosomal compensation appears to exist between maize and Z. perennis. A rise in the ploidy of the trihybrids was linked to a higher frequency of chromosomal translocation. Variation in the degree of phenotypic diversity observed in different segregating populations suggested that genome dosage effects phenotypic manifestation. These findings not only broaden our understanding of the mechanisms of polyploid formation and reproductive diversity but also provide a novel insight into genome pyramiding and shuffling driven genome dosage effects and phenotypic diversity.

QTL-seq and transcriptomic integrative analyses reveal two positively regulated genes that control the low-temperature germination ability of MTP-maize introgression lines.

KEY MESSAGE: Two candidate genes (ZmbZIP113 and ZmTSAH1) controlling low-temperature germination ability were identified by QTL-seq and integrative transcriptomic analyses. The functional verification results showed that two candidate genes positively regulated the low-temperature germination ability of IB030. Low-temperature conditions cause slow maize (Zea mays L.) seed metabolism, resulting in slow seedling emergence and irregular seedling emergence, which can cause serious yield loss. Thus, improving a maize cultivar's low-temperature germination ability (LTGA) is vital for increasing yield production. Wild relatives of maize, such as Z. perennis and Tripsacum dactyloides, are strongly tolerant of cold stress and can thus be used to improve the LTGA of maize. In a previous study, the genetic bridge MTP was constructed (from maize, T. dactyloides, and Z. perennis) and used to obtain a highly LTGA maize introgression line (IB030) by backcross breeding. In this study, IB030 (Strong-LTGA) and Mo17 (Weak-LTGA) were selected as parents to construct an F2 offspring. Additionally, two major QTLs (qCS1-1 and qCS10-1) were mapped. Then, RNA-seq was performed using seeds of IB030 and the recurrent parent B73 treated at 10 °C for 27 days and 25 °C for 7 days, respectively, and two candidate genes (ZmbZIP113 and ZmTSAH1) controlling LTGA were located using QTL-seq and integrative transcriptomic analyses. The functional verification results showed that the two candidate genes positively regulated LTGA of IB030. Notably, homologous cloning showed that the source of variation in both candidate genes was the stable inheritance of introgressed alleles from Z. perennis. This study was thus able to analyze the LTGA mechanism of IB030 and identify resistance genes for genetic improvement in maize, and it proved that using MTP genetic bridge confers desirable traits or phenotypes of Z. perennis and tripsacum essential to maize breeding systems.

Multispecies polyploidization, chromosome shuffling, and genome extraction in Zea/Tripsacum hybrids.

By hybridization and special sexual reproduction, we sequentially aggregated Zea mays, Zea perennis, and Tripsacum dactyloides in an allohexaploid, backcrossed it with maize, derived self-fertile allotetraploids of maize and Z. perennis by natural genome extraction, extended their first six selfed generations, and finally constructed amphitetraploid maize using nascent allotetraploids as a genetic bridge. Transgenerational chromosome inheritance, subgenome stability, chromosome pairings and rearrangements, and their impacts on an organism's fitness were investigated by fertility phenotyping and molecular cytogenetic techniques genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH). Results showed that diversified sexual reproductive methods produced highly differentiated progenies (2n = 35-84) with varying proportions of subgenomic chromosomes, of which one individual (2n = 54, MMMPT) overcame self-incompatibility barriers and produced a self-fertile nascent near-allotetraploid by preferentially eliminating Tripsacum chromosomes. Nascent near-allotetraploid progenies showed persistent chromosome changes, intergenomic translocations, and rDNA variations for at least up to the first six selfed generations; however, the mean chromosome number preferably maintained at the near-tetraploid level (2n = 40) with full integrity of 45S rDNA pairs, and a trend of decreasing variations by advancing generations with an average of 25.53, 14.14, and 0.37 for maize, Z. perennis, and T. dactyloides chromosomes, respectively. The mechanisms for three genome stabilities and karyotype evolution for formatting new polyploid species were discussed.

QTL Mapping and a Transcriptome Integrative Analysis Uncover the Candidate Genes That Control the Cold Tolerance of Maize Introgression Lines at the Seedling Stage.

Chilling injury owing to low temperatures severely affects the growth and development of maize (Zea mays.L) seedlings during the early and late spring seasons. The existing maize germplasm is deficient in the resources required to improve maize's ability to tolerate cold injury. Therefore, it is crucial to introduce and identify excellent gene/QTLs that confer cold tolerance to maize for sustainable crop production. Wild relatives of maize, such as Z. perennis and Tripsacum dactyloides, are strongly tolerant to cold and can be used to improve the cold tolerance of maize. In a previous study, a genetic bridge among maize that utilized Z. perennis and T. dactyloides was created and used to obtain a highly cold-tolerant maize introgression line (MIL)-IB030 by backcross breeding. In this study, two candidate genes that control relative electrical conductivity were located on MIL-IB030 by forward genetics combined with a weighted gene co-expression network analysis. The results of the phenotypic, genotypic, gene expression, and functional verification suggest that two candidate genes positively regulate cold tolerance in MIL-IB030 and could be used to improve the cold tolerance of cultivated maize. This study provides a workable route to introduce and mine excellent genes/QTLs to improve the cold tolerance of maize and also lays a theoretical and practical foundation to improve cultivated maize against low-temperature stress.

Integrated single-molecule real-time sequencing and RNA sequencing reveal the molecular mechanisms of salt tolerance in a novel synthesized polyploid genetic bridge between maize and its wild relatives.

BACKGROUND: Tripsacum dactyloides (2n = 4x = 72) and Zea perennis (2n = 4x = 40) are tertiary gene pools of Zea mays L. and exhibit many abiotic adaptations absent in modern maize, especially salt tolerance. A previously reported allopolyploid (hereafter referred to as MTP, 2n = 74) synthesized using Zea mays, Tripsacum dactyloides, and Zea perennis has even stronger salt tolerance than Z. perennis and T. dactyloides. This allopolyploid will be a powerful genetic bridge for the genetic improvement of maize. However, the molecular mechanisms underlying its salt tolerance, as well as the key genes involved in regulating its salt tolerance, remain unclear. RESULTS: Single-molecule real-time sequencing and RNA sequencing were used to identify the genes involved in salt tolerance and reveal the underlying molecular mechanisms. Based on the SMRT-seq results, we obtained 227,375 reference unigenes with an average length of 2300 bp; most of the unigenes were annotated to Z. mays sequences (76.5%) in the NR database. Moreover, a total of 484 and 1053 differentially expressed genes (DEGs) were identified in the leaves and roots, respectively. Functional enrichment analysis of DEGs revealed that multiple pathways responded to salt stress, including "Flavonoid biosynthesis," "Oxidoreductase activity," and "Plant hormone signal transduction" in the leaves and roots, and "Iron ion binding," "Acetyl-CoA carboxylase activity," and "Serine-type carboxypeptidase activity" in the roots. Transcription factors, such as those in the WRKY, B3-ARF, and bHLH families, and cytokinin negatively regulators negatively regulated the salt stress response. According to the results of the short time series-expression miner analysis, proteins involved in "Spliceosome" and "MAPK signal pathway" dynamically responded to salt stress as salinity changed. Protein-protein interaction analysis revealed that heat shock proteins play a role in the large interaction network regulating salt tolerance. CONCLUSIONS: Our results reveal the molecular mechanism underlying the regulation of MTP in the response to salt stress and abundant salt-tolerance-related unigenes. These findings will aid the retrieval of lost alleles in modern maize and provide a new approach for using T. dactyloides and Z. perennis to improve maize.

The Role of Depressive Symptoms and Physical Activity Levels in Mediating the Association Between HIV Status and Neurocognitive Functions Among Individuals Aged at Least 50 Years in China: Cross-sectional Study.

BACKGROUND: Neurocognitive impairments are prevalent among older people in China. It is more problematic among older people living with HIV. OBJECTIVE: This study aims to compare neurocognitive performance between older people living with HIV and HIV-negative controls, and to explore whether the association between HIV status and neurocognitive performance was mediated by depressive symptoms and level of physical activity. METHODS: A cross-sectional study was conducted in Yongzhou, China. All people living with HIV aged ≥50 years listed in the registry were invited. Frequency matching was used to sample HIV-negative controls from the general population according to the distribution of age, sex, and years of formal education of older people living with HIV. A total of 315 older people living with HIV and 350 HIV-negative controls completed the face-to-face interview and comprehensive neuropsychological assessment of seven domains (learning, memory, working memory, verbal fluency, processing speed, executive function, and motor skills). RESULTS: As compared to HIV-negative controls, older people living with HIV performed worse in global score and all seven domains (P<.05). HIV infection was associated with higher depressive symptoms (P<.001) and lower level of physical activity (P<.001). Depressive symptoms and physical activity were negatively correlated (P<.001). Depressive symptoms and level of physical activity mediated the association between HIV status and global z-score and four domain z-scores of neurocognitive performance (learning, memory, verbal fluency, and processing speed). CONCLUSIONS: Change in mental health and physical activity after HIV infection may partially explain why older people living with HIV are more susceptible to neurocognitive impairment. Promoting mental health and physical activity are potential entry points to slow down the progress of neurocognitive impairment among older people living with HIV.

Epidemiology and Clinical Outcomes of HIV Infection in South-Central China: A Retrospective Study From 2003 to 2018.

Objective: HIV epidemiology in South-Central China is rarely reported. This study aims to characterize epidemiological and clinical features of HIV-infected patients in Hunan Province, located in South-Central China, for better management of HIV infections. Methods: This retrospective study retrieved multi-center records of laboratory-confirmed HIV-infected patients in Hunan province. Information on HIV-associated mortality and antiretroviral therapies was also collected. Results: Among 34,297 patients diagnosed with HIV infections from 2003 to 2018, 73.9% were males, 41.3% were older adults (≥50 years), and 71.2% were infected by heterosexual transmission. Despite a slow growth of new HIV infections in the overall population, annual percentages of HIV infections increased in older males (85.3% through heterosexual transmission) and young patients <30 years (39.9% through homosexual transmission). At baseline, serum levels of CD4+ T-cell counts were lower in older adults (191.0 cells/µl) than in young patients (294.6 cells/µl, p-value < 0.0001). A large proportion (47.2%, N = 16,165) of HIV-infected patients had advanced HIV disease (CD4+ T-cell counts < 200 cells/µl) from 2003 to 2018. All-cause mortality (57.0% due to AIDS-related illnesses) was reported among 4411 HIV-infected patients, including 2619 older adults. The 10-year survival rate was significantly lower in elderly males than in other patients (59.0 vs. 78.4%, p-value < 0.05). Conclusions: Elderly males are prone to HIV infections with a high risk of HIV-associated fatality. Our findings support early prevention and critical care for elderly populations to control HIV infections.

Older People Living with HIV Were Less Physically Active Than Their Uninfected Counterparts in China: A Matched-Sample Mediation Analysis.

The study compared the level of physical activity (PA) between older people living with HIV (PLWH) and their HIV-negative counterparts in China and tested the mediational roles of self-compassion, attitudes toward aging, and perceived stress in the between-group difference in PA. From December 2017 to August 2018, face-to-face interviews were conducted among 337 and 363 HIV-positive and -negative people aged ≥ 50 in Yongzhou City, Hunan, China. Path analysis was performed. The proportions of low, moderate, and high levels of PA in the HIV-positive and -negative groups were 18.9% versus 6.7%, 43.1% versus 32.0%, and 38.0% versus 61.3%, respectively, yielding a statistically significant difference. The path analysis showed that older PLWH reported less self-compassion and positive attitudes toward aging, which was in turn associated with more perceived stress and ultimately associated with less PA. Chinese older PLWH were more sedentary than their HIV-negative counterparts. Future PA interventions may modify the mediators.

Evaluation of effectiveness, safety and cost-benefit of the 23- valent pneumococcal capsular polysaccharide vaccine for HIV-Infected patients.

INTRODUCTION: Due to the lack of understanding of the protective effects and safety of 23-valent pneumococcal polysaccharide vaccine (PPV23) in immune-deficient populations, the vaccination rate of PPV23 among HIV-infected patients is still very low in China. The main objectives of this study were to determine whether the efforts to assess measures for the prevention of pneumococcal pneumonia are still worthwhile, and provide designated vaccination program of HIV-infected persons for government policy based on. METHODS: 60 HIV-infected adults in Lanshan county who had never been vaccinated with any pneumococcal vaccine were enrolled in this study, voluntary vaccination of PPV23 and One-year follow-up after vaccination can be completed. RESULT: 76.67% patients (46/60) had serologic response at 12 months after vaccine, CD4 count(≤500 cells/ul or > 500 cells/ul) and Month from diagnosis to first antiviral therapy (≤1 month or > 1 month) were related to antibody responses (p < 0.05).In this study, PPV23 was well tolerated, no adversereaction was reported.11 Streptococcus pneumoniae pneumonia (9.17%,11/120) occurred in the Unvaccinated group and 1 case(1.67%,1/60)in the vaccination group within one year after vaccination(Fisher's exact probability, P = 0.225). The VE was 81.79%. The per capita benefit was 39.32 dollars, thebenefit-costratio = 1.19. There are significant statistical differences between the vaccinated group and the non-vaccinated group in outpatient costs (p < 0.05, 95 %CI: 9.29-32.11), Medicine costs (p = 0.017, 95 %CI: 2.47-24.44), and disease related indirect costs (p = 0.038, 95 %CI: 0.93-33.63) within one year of vaccination. CONCLUSION: Our study results showed that PPV23 can be safely and effectively administered to HIV-1 infected individuals and effectively preventing Streptococcal pneumonia. Considering the cost-benefit of vaccination among HIV-infected persons, as it has been reported in our study, it is necessary to promote the widespread use of the vaccine among HIV-infected persons in the future.

Negative attitudes toward aging mediated the association between HIV status and depression among older people in mainland china.

BACKGROUND: In China, people living with HIV (PLWH) are aging. The study compared prevalence of probable depression between older PLWH and their HIV-negative counterparts, and tested the hypothesis that the between-group difference in depressive symptoms would be mediated by attitudes toward aging. METHODS: With informed consent, a cross-sectional survey was conducted via anonymous face-to-face interviews to 337 and 363 HIV-positive and HIV-negative people aged ≥50, respectively, in Yongzhou City, Hunan, China from December 2017 to August 2018. Depression was measured by the Center for Epidemiologic Studies Depression (CES-D) scale. Attitudes toward aging were measured by the Attitudes to Aging Questionnaire (subdomains: psychosocial loss, physical change, psychological growth). Bootstrapping analyses were performed to test the mediation hypothesis. RESULTS: The prevalence of probable depression (CES-D ≥ 16) was significantly higher in the HIV-positive group than the HIV-negative group (44.8% versus 20.4%). The HIV-positive participants presented more negative attitudes toward aging (in psychosocial loss and physical change) than their HIV-negative counterparts. Negative attitudes toward aging were associated with more depressive symptoms. Overall attitudes toward aging (effect size=41.3%) and the subdomains of psychosocial loss (effect size=38.5%) and physical change (effect size=16.3%) partially mediated the association between HIV status and depressive symptoms, respectively. LIMITATIONS: The cross-sectional design limited the ability of causal inference. Selection bias, information bias, and confounding bias might exist. CONCLUSIONS: Older PLWH might be more depressed than their HIV-negative counterparts in mainland China, partially because they possessed more negative attitudes toward aging. Interventions for depression may include components of improving attitudes toward aging.

Analysis of the genitor origin of an intergeneric hybrid clone between Zea and Tripsacum for forage production by McGISH.

In this study, the chromosome number and composition of a novel perennial forage crop, 'Yucao No. 6' (Yu6), was revealed by chromosome spread and McGISH (multicolor genomic in situ hybridization) techniques to clarify its genitor origin. Cytogenetic analysis showed that Yu6, which has 56 chromosomes, is an aneuploid representing 12, 17 and 27 chromosomes from Zea mays ssp. mays L. (Zm, 2n = 2x = 20), Tripsacum dactyloides L. (Td, 2n = 4x = 72), and Z. perennis (Hitchc.) Reeves & Mangelsd. (Zp, 2n = 4x = 40), respectively. This finding indicates that Yu6 is the product of a reduced egg (n = 36 = 12Zm + 17Td + 7Zp) of MTP (a near-allohexaploid hybrid, 2n = 74 = 20Zm + 34Td + 20Zp) fertilized by a haploid sperm nucleus (n = 20Zp) of Z. perennis. Moreover, 3 translocated chromosomes consisting of the maize-genome chromosome with the segment of Z. perennis were observed. These results suggest that it is practical to develop perennial forage maize by remodeling the chromosomal architecture of MTP offspring with Z. perennis as a pollen parent. Finally, the overview of forage breeding in the Zea and Tripsacum genera was discussed.

Pretreatment HIV drug resistance in adults initiating antiretroviral therapy in China, 2017.

BACKGROUND: After the scale-up of antiretroviral therapy (ART) for HIV infected people, increasing numbers of patients have pretreatment drug resistance (PDR). In this study, the prevalence of PDR was evaluated in adults initiating antiretroviral therapy in China. METHODS: Blood samples were obtained from 1943 patients who initiated antiretroviral therapy (ART) in 2017 from 13 provinces or cities in China. Pol sequences were used to analyze drug resistance and construct transmission networks. Logistic regression model was used to estimate the potential factors associated with PDR. RESULTS: In total, 1711 eligible patients (76.0% male; 87.8% aged ≥ 25 years) were included, of which 117 (6.8%) had PDR. The highest rates of PDR were 12.2% in Liangshan Prefecture of Sichuan and 9.3 and 8.9% in Dehong and Lincang Prefecture of Yunnan. A multivariate logistic regression analysis revealed that PDR was significantly higher among intravenous drug users (adjusted Odds Ratio (aOR) = 2.64, 95% CI: 1.57-4.44) and individuals from Liangshan, Dehong, and Lincang (aOR = 2.04, 95% CI: 1.26-3.30). In total, 754 sequences were used to generate 164 transmission networks. Five transmission networks had two or three sequences containing the same mutations, two networks contained subjects from Liangshan, and one network contained subjects from Dehong. CONCLUSIONS: Overall, the PDR prevalence was moderate, with a particularly high prevalence in areas with severe HIV epidemics. These results indicate the importance of continuous PDR monitoring in patients initiating antiretroviral therapy.

Prevalence of acquired drug resistance mutations in antiretroviral- experiencing subjects from 2012 to 2017 in Hunan Province of central South China.

BACKGROUND: There are few data on the prevalence of acquired drug resistance mutations (ADRs) in Hunan Province, China, that could affect the effectiveness of antiretroviral therapy (ART). OBJECTIVES: The main objectives of this study were to determine the prevalence of acquired drug resistance (ADR) the epidemic characteristics of HIV-1-resistant strains among ART-failed HIV patients in Hunan Province, China. METHODS: ART-experienced and virus suppression failure subjects in Hunan between 2012 and 2017 were evaluated by genotyping analysis and mutations were scored using the HIVdb.stanford.edu algorithm to infer drug susceptibility. RESULTS: The prevalence of HIV-1 ADR were 2.76, 2.30, 2.98, 2.62, 2.23and 2.17%, respectively, from 2012 to 2017. Overall 2295 sequences were completed from 2932 ART-failure patients, and 914 of these sequences were found to have drug resistance mutation. The most common subtype was AE (64.14%), followed by BC (17.91%) and B (11.50%). Among those 914 patients with drug resistance mutations,93.11% had NNRTI-associated drug resistance mutations, 74.40% had NRTI drug resistance mutations (DRMs) and 6.89% had PI DRMs. Dual-class mutations were observed in 591 (64.66%) cases, and triple-class mutations were observed in 43 (4.70%) cases. M184V (62.04%), K103N (41.90%) and I54L (3.83%) were the most common observed mutations, respectively, in NRTI-, NNRTI- and PI-associated drug resistance. 93.76% subjects who had DRMs received the ART first-line regimens. CD4 count, symptoms in the past 3 months, and ART adherence were found to be associated with HIV-1 DR. CONCLUSIONS: This study showed that although the prevalence of HIV-acquired resistance in Hunan Province is at a low-level, the long-term and continuous surveillance of HIV ADR in antiretroviral drugs (ARVs) patients is necessary.

Efavirenz use and neurocognitive performance among older people living with HIV who were on antiretroviral therapy.

This study was to compare global and domain-specific neurocognitive performance between older people living with HIV (PLWH) taking/not taking efavirenz (EFV) and HIV-negative controls. A cross-sectional study was conducted in Yongzhou city, China. All PLWH older than 50 years listed on the registry of Centres for Disease Control and Prevention were invited to join the study. Frequency matching was used to sample HIV-negative controls according to the distribution of age, sex, and years of formal education of older PLWH. A total of 308 older PLWH and 350 HIV-negative controls completed the face-to-face interview and neurocognitive assessment using the comprehensive neuropsychological test battery. After adjusting for significant confounders, older PLWH taking EFV showed poorer performance in memory (p = 0.020), verbal fluency (p = 0.002), and poorer global neurocognitive performance (p = 0.032) than those without EFV use. Compared to HIV-negative controls, older PLWH taking EFV had poorer performance in all neurocognitive domains (p values: <0.001-0.003) and poorer global neurocognitive performance (p < 0.001). Similar trends were observed when comparing older PLWH without using EFV versus HIV-negative controls, with the exception of verbal fluency (p = 0.560). Health care workers should monitor the neuropsychological performance of older PLWH, epically those who were taking EFV. Longitudinal studies are warranted.

OsNAC2 integrates auxin and cytokinin pathways to modulate rice root development.

The rice root system is important for growth. The crosstalk between auxin and cytokinin mediates root initiation and elongation. However, it remains unclear how the transcriptional network upstream of the auxin and cytokinin signalling pathways determines root development. Here, we observed that the knockdown of OsNAC2, which encodes a NAC transcription factor, increased the primary root length and the number of crown roots. OsNAC2 predominantly expressed in primary root tips, crown roots and lateral root primordia, implying it influences root development. Molecular analyses revealed that the expressions of auxin- and cytokinin-responsive genes were affected in OsNAC2-overexpressing (OsNAC2-OX; ON7 and ON11), RNA interference (OsNAC2-RNAi; RNAi25 and RNAi31) and CRISPR/Cas9 plants. Additionally, OsNAC2 can directly bind to the promoters of IAA inactivation-related genes (GH3.6 and GH3.8), an IAA signalling-related gene (OsARF25), and a cytokinin oxidase gene (OsCKX4). Furthermore, genetic analysis of ON11/osgh3.6 and RNAi31/osckx4 homozygote confirmed that OsCKX4 and OsGH3.6 functioned downstream of OsNAC2. The mRNA levels of CROWN ROOTLESS (CRL) genes and cyclin-dependent protein kinase (CDK) genes increased in OsNAC2-RNAi and OsNAC2-cas9 lines while reduced in OsNAC2-OX lines. Thus, we describe that OsNAC2 functions as an upstream integrator of auxin and cytokinin signals that affect CRL and CDK production to regulate cell division during root development. This novel auxin-OsNAC2-cytokinin model should provide a new insight into the understanding of NAC TFs and crosstalk of auxin and cytokinin pathway, and can be potentially applied in agriculture to enhance rice yields by genetic approaches.

Tripsazea, a Novel Trihybrid of Zea mays, Tripsacum dactyloides, and Zeaperennis.

A trispecific hybrid, MTP (hereafter called tripsazea), was developed from intergeneric crosses involving tetraploid Zea mays (2n = 4x = 40, genome: MMMM), tetraploid Tripsacum dactyloides (2n = 4x = 72, TTTT), and tetraploid Zperennis (2n = 4x = 40, PPPP). On crossing maize-Tripsacum (2n = 4x = 56, MMTT) with Zperennis, 37 progenies with varying chromosome numbers (36-74) were obtained, and a special one (i.e., tripsazea) possessing 2n = 74 chromosomes was generated. Tripsazea is perennial and expresses phenotypic characteristics affected by its progenitor parent. Flow cytometry analysis of tripsazea and its parents showed that tripsazea underwent DNA sequence elimination during allohexaploidization. Of all the chromosomes in diakinesis I, 18.42% participated in heterogenetic pairing, including 16.43% between the M- and P-genomes, 1.59% between the M- and T-genomes, and 0.39% in T- and P-genome pairing. Tripsazea is male sterile and partly female fertile. In comparison with previously synthesized trihybrids containing maize, Tripsacum and teosinte, tripsazea has a higher chromosome number, higher seed setting rate, and vegetative propagation ability of stand and stem. However, few trihybrids possess these valuable traits at the same time. The potential of tripsazea is discussed with respect to the deployment of the genetic bridge for maize improvement and forage breeding.

[An investigation of vaccination in children with human immunodeficiency virus infection].

OBJECTIVE: To investigate the status of vaccination in children with human immunodeficiency virus (HIV) infection. METHODS: A questionnaire survey was performed in 148 children in Hunan province, China who were registered in China's Acquired Immune Deficiency Syndrome Comprehensive Response Information Management System up to December 31, 2016 and were aged <15 years at the time of confirmed diagnosis of HIV infection. The information on vaccination, diagnosis of HIV infection, and diagnosis and treatment of related diseases was collected. RESULTS: Of the 148 children with HIV infection, there were 70 boys (47.3%) and 78 girls (52.7%); 140 children had an age of 3.8 (0.2-14.8) years at the time of confirmed diagnosis, and 8 children refused to answer this question. Mother-to-child transmission was found in 133 children (91.7%), blood transmission in 1 child (0.7%), and unknown in 14 children (9.5%). Of the 148 children, 129 (87.2%) received antiviral therapy and 19 (12.8%) did not receive such treatment. The vaccination rates of hepatitis B vaccine, bacille Calmette-Guérin vaccine, poliomyelitis live attenuated vaccine and diphtheria-pertussis-tetanus vaccine ranged from 70.9% to 77.7%, which was significantly lower than the national level (≥97%); the vaccination rates of the other vaccines in the National Immunization Program gradually decreased with age. No severe adverse effects were reported after vaccination. CONCLUSIONS: Mother-to-child transmission is the main route of HIV infection in Chinese children. The diagnosis of children with HIV infection is significantly delayed, with low vaccination rates. Efforts should be made to strengthen early diagnosis, early treatment and vaccination in children with HIV infection, in order to improve their quality of life.