The F-box protein ZmFBL41 negatively regulates disease resistance to Rhizoctonia solani by degrading the abscisic acid synthase ZmNCED6 in maize.

KEY MESSAGE: The maize F-box protein ZmFBL41 targets abscisic acid synthase 9-cis-epoxycarotenoid dioxygenase 6 for degradation, and this regulatory module is exploited by Rhizoctonia solani to promote infection. F-box proteins are crucial regulators of plant growth, development, and responses to abiotic and biotic stresses. Previous research identified the F-box gene ZmFBL41 as a negative regulator of maize (Zea mays) defenses against Rhizoctonia solani. However, the precise mechanisms by which F-box proteins mediate resistance to R. solani remain poorly understood. In this study, we show that ZmFBL41 interacts with an abscisic acid (ABA) synthase, 9-cis-epoxycarotenoid dioxygenase 6 (ZmNCED6), promoting its degradation via the ubiquitination pathway. We discovered that the ectopic overexpression of ZmNCED6 in rice (Oryza sativa) inhibited R. solani infection by activating stomatal closure, callose deposition, and jasmonic acid (JA) biosynthesis, indicating that ZmNCED6 enhances plant immunity against R. solani. Natural variation at ZmFBL41 across different maize haplotypes did not affect the ZmFBL41-ZmNCED6 interaction. These findings suggest that ZmFBL41 targets ZmNCED6 for degradation, leading to a decrease in ABA levels in maize, in turn, inhibiting ABA-mediated disease resistance pathways, such as stomatal closure, callose deposition, and JA biosynthesis, ultimately facilitating R. solani infection.

Transcriptome analysis reveals genes potentially related to maize resistance to Rhizoctonia solani.

Banded leaf and sheath blight (BLSB) is a devasting disease caused by the necrotrophic fungus Rhizoctonia solani that affects maize (Zea mays L.) fields worldwide, especially in China and Southeast Asia. Understanding how maize plants respond to R. solani infection is a key step towards controlling the spread of this fungal pathogen. In this study, we determined the transcriptome of maize plants infected by a low-virulence strain (LVS) and a high-virulence strain (HVS) of R. solani for 3 and 5 days by transcriptome deep-sequencing (RNA-seq). We identified 3,015 (for LVS infection) and 1,628 (for HVS infection) differentially expressed genes (DEGs). We confirmed the expression profiles of 10 randomly selected DEGs by quantitative reverse transcription PCR. We also performed a Gene Ontology (GO) enrichment analysis to establish which biological processes are associated with these DEGs, which revealed the enrichment of defense-related GO terms in LVS- and HVS-regulated genes. We selected 388 DEGs upregulated upon fungal infection as possible candidate genes. Among them, the overexpression of ZmNAC41 (encoding NAC transcription factor 41) or ZmBAK1 (encoding BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1) in rice enhanced resistance to R. solani. In addition, overexpressing ZmBAK1 in rice also increased plant height, plant weight, thousand-grain weight, and grain length. The identification of 388 potential key maize genes related to resistance to R. solani provides significant insights into improving BLSB resistance.

The Complete Mitochondrial Genome of Plectorhinchus Chaetodonoides (Perciformes: Haemulidae).

Plectorhinchus chaetodonoides Lacepède, 1801 is a widespread multicolored sweetlips fish found in the Indo-West Pacific Ocean where its appearance and color patterns drastically change during growth. In this study, the whole mitochondrial genome of P. chaetodonoides was sequenced which revealed it is 16,546 bp long and contains 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and one noncoding regulatory region. The GC content of the whole genome was 47.5% and 48.2%, 46.3%, 46.8%, 42.5% in the protein coding genes, tRNAs, rRNAs, and control regions, respectively. Molecular phylogenetic analysis resolved P. chaetodonoides as closely associated with Diagramma pictum and nested within a clade of Haemulidae that is allied with species from the Lutjanidae, Kyphosidae, Teraponidae, and Sciaenidae families. These results provide an essential genomic resource for future evolutionary and conservation studies of P. chaetodonoides as well as the Haemulidae family.

Tumor Suppressor Candidate 1 Suppresses Cell Growth and Predicts Better Survival in Glioblastoma.

Glioblastoma (GBM) is the most common malignant brain tumor with poor prognosis and limited treatment options. Tumor suppressor candidate 1 (TUSC1) was recently identified as a potential tumor suppressor in human cancers. However, the expression and potential function of TUSC1 in GBM remain unclear. Herein, we report that TUSC1 is significantly decreased in GBM tissues and cell lines. Patients with high levels of TUSC1 displayed a significant better survival compared with those with low levels of TUSC1. Functional experiments demonstrated that exogenous expression of TUSC1 inhibited GBM cell proliferation and induced G1 phase arrest by down-regulating CDK4. Moreover, overexpression of TUSC1 retarded tumor growth in vivo. Together, our findings revealed that TUSC1 might be a crucial tumor suppressor gene and a novel therapeutic target for GBM.

Association of serum 25-hydroxyvitamin D status with bone mineral density in 0-7 year old children.

OBJECTIVE: To describe the status of serum 25-hydoxyvitamin D [25(OH)D] concentrations and identify the relationship between 25(OH)D and bone mineral density (BMD). In an effort to explore the appropriate definition of vitamin D (VD) deficiency in 0-7 year old children. RESULTS: The median serum 25(OH)D concentrations was 62.9 nmol/L and 28.9% of the children had a low 25(OH)D (< 50 nmol/L). And a linear relation between 25(OH)D concentrations and BMD was surveyed (r = 0.144 , P < 0.001). After adjusting for the confounders, serum 25(OH)D was positively associated with BMD (ß = 172.0, 95%CI = 142.8-201.2, P < 0.001), and low 25(OH)D (< 75 nmol/L) had a high stake for low BMD (OR = 1.424, 95%CI = 1.145-1.769, P = 0.001). Additionally, there was a nonlinear relation between 25(OH)D and low BMD, and a critical value for 25(OH)D of 75 nmol/L appeared for low BMD. The prevalence of low BMD was 14.1% in children with 25(OH)D ≥ 75 nmol/L, much lower than that of the concentrations between 50-75 nmol/L and < 50 nmol/L. MATERIALS AND METHODS: A total of 4,846 children 0-7 years old were recruited in Jiangsu Province, China. BMD and serum 25(OH)D concentrations were determined by quantitative ultrasound and enzyme-linked immunosorbent assay, respectively. Linear regression and logistic regression analyses were used to assess the association of 25(OH)D concentrations with BMD. CONCLUSIONS: Serum 25(OH)D concentrations was related with BMD and 25(OH)D concentrations < 75 nmol/L might be a more appropriate definition of VD deficiency in 0-7 year old children.

Optimal level of 25-(OH)D in children in Nanjing (32°N Lat) during winter.

BACKGROUND: The optimal serum level of 25-hydroxyvitamin D (25-(OH)D) for bone health is still unclear, especially in children. Hypovitaminosis D is also re-emerging in developed and developing countries. The purpose of the present study was therefore to determine optimal serum 25-(OH)D level and preliminarily identify the vitamin D nutritional status in Nanjing children. METHODS: All subjects (76 healthy, 66 suffering from infectious diseases) aged 0-10 years were recruited during the period December 2007-March 2008. Venous blood samples were collected before breakfast and the levels of serum 25-(OH)D, parathyroid hormone (PTH), bone-specific alkaline phosphatase (BAP), calcium (Ca), phosphorus (P) were determined. The optimal level of serum 25-(OH)D was explored using the three response curves of 25-(OH)D versus PTH, 25-(OH)D versus BAP, and 25-(OH)D versus Ca×P product. RESULTS: For 25-(OH)D ≤ 50 nmol/L, PTH and BAP were both inversely correlated with 25-(OH)D (PTH, r=-0.864, P < 0.01; BAP, r=-0.856, P < 0.01). For 25-(OH)D > 50-60 nmol/L, levels of PTH and BAP remained steady. With regard to the Ca×P product, for 25-(OH)D ≤ 50 nmol/L, Ca×P product increased as 25-(OH)D increased (r= 0.037, P > 0.05). For 25-(OH)D > 50-60 nmol/L, Ca×P product remained steady. The mean serum level of 25-(OH)D was 80.5 ± 29.3 nmol/L (mean ± SD) in the healthy children, and 65.7 ± 32.3 nmol/L in the sick children. CONCLUSION: The optimal 25-(OH)D level may be 50-60 nmol/L for bone health in Nanjing children. The vitamin D nutritional status of Nanjing children is relatively good in winter.