The lipoxygenase OsLOX10 affects seed longevity and resistance to saline-alkaline stress during rice seedlings.

Prolonged storage of rice seeds can lead to a decrease in seed vigor and seedling quality. The Lipoxygenase (LOX) gene family is widely distributed in plants, and LOX activity is closely related to seed viability and stress tolerance. In this study, the lipoxygenase OsLOX10 gene from the 9-lipoxygenase metabolic pathway was cloned from rice, and its roles in determining seed longevity and tolerance to saline-alkaline stress caused by Na2CO3 in rice seedlings were mainly investigated. CRISPR/Cas9 knockout of OsLOX10 increased seed longevity compared with the wild-type and OsLOX10 overexpression lines in response to artificial aging. The expression levels of other 9-lipoxygenase metabolic pathway related genes, such as LOX1, LOX2 and LOX3, were increased in the LOX10 overexpression lines. Quantitative real-time PCR and histochemical staining analysis showed that the expression of LOX10 was highest in seed hulls, anthers and the early germinating seeds. KI-I2 staining of starch showed that LOX10 could catalyze the degradation of linoleic acid. Furthermore, we found that the transgenic lines overexpressing LOX10 showed better tolerance to saline-alkaline stress than the wild-type and knockout mutant lines. Overall, our study demonstrated that the knockout LOX10 mutant increased seed longevity, whereas overexpression of LOX10 enhanced tolerance to saline-alkaline stress in rice seedlings.

Ubiquitylomes and proteomes analyses provide a new interpretation of the molecular mechanisms of rice leaf senescence.

MAIN CONCLUSION: We identified a typical rice premature senescence leaf mutant 86 (psl86) and exhibited the first global ubiquitination data during rice leaf senescence. Premature leaf senescence affects the yield and quality of rice, causing irreparable agricultural economic losses. In this study, we reported a rice premature senescence leaf mutant 86 (psl86) in the population lines of rice (Oryza sativa) japonica cultivar 'Yunyin' (YY) mutagenized using ethyl methane sulfonate (EMS) treatment. Immunoblotting analysis revealed that a higher ubiquitination level in the psl86 mutant compared with YY. Thus, we performed the proteome and ubiquitylome analyses to identify the differential abundance proteins and ubiquitinated proteins (sites) related to leaf senescence. Among 885 quantified lysine ubiquitination (Kub) sites in 492 proteins, 116 sites in 94 proteins were classified as up-regulated targets and seven sites in six proteins were classified as down-regulated targets at a threshold of 1.5. Proteins with up-regulated Kub sites were mainly enriched in the carbon fixation in photosynthetic organisms, glycolysis/gluconeogenesis and the pentose phosphate pathway. Notably, 14 up-regulated Kub sites in 11 proteins were enriched in the carbon fixation in photosynthetic organism pathway, and seven proteins (rbcL, PGK, GAPA, FBA5, ALDP, CFBP1 and GGAT) were down-regulated, indicating this pathway is tightly regulated by ubiquitination during leaf senescence. To our knowledge, we present the first global data on ubiquitination during rice leaf senescence.

An eight-miRNA signature as a potential biomarker for predicting survival in lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma is a heterogernous disease that creates challenges for classification and management. The purpose of this study is to identify specific miRNA markers closely associated with the survival of LUAD patients from a large dataset of significantly altered miRNAs, and to assess the prognostic value of this miRNA expression profile for OS in patients with LUAD. METHODS: We obtained miRNA expression profiles and corresponding clinical information for 372 LUAD patients from The Cancer Genome Atlas (TCGA), and identified the most significantly altered miRNAs between tumor and normal samples. Using survival analysis and supervised principal components method, we identified an eight-miRNA signature for the prediction of overall survival (OS) of LUAD patients. The relationship between OS and the identified miRNA signature was self-validated in the TCGA cohort (randomly classified into two subgroups: n = 186 for the training set and n = 186 for the testing set). Survival receiver operating characteristic (ROC) analysis was used to assess the performance of survival prediction. The biological relevance of putative miRNA targets was also analyzed using bioinformatics. RESULTS: Sixteen of the 111 most significantly altered miRNAs were associated with OS across different clinical subclasses of the TCGA-derived LUAD cohort. A linear prognostic model of eight miRNAs (miR-31, miR-196b, miR-766, miR-519a-1, miR-375, miR-187, miR-331 and miR-101-1) was constructed and weighted by the importance scores from the supervised principal component method to divide patients into high- and low-risk groups. Patients assigned to the high-risk group exhibited poor OS compared with patients in the low-risk group (hazard ratio [HR] = 1.99, P <0.001). The eight-miRNA signature is an independent prognostic marker of OS of LUAD patients and demonstrates good performance for predicting 5-year OS (Area Under the respective ROC Curves [AUC] = 0.626, P = 0.003), especially for non-smokers (AUC = 0.686, P = 0.023). CONCLUSIONS: We identified an eight-miRNA signature that is prognostic of LUAD. The miRNA signature, if validated in other prospective studies, may have important implications in clinical practice, in particular identifying a subgroup of patients with LUAD who are at high risk of mortality.

Function verification of a chlorophyll a/b binding protein gene through a newly established tobacco rattle virus-induced gene silencing system in Kandelia obovata.

As an important mangrove species, Kandelia obovata plays an irreplaceable role in the coastal ecosystem. However, due to a lack of genetic technology, there is limited research on its functional genes. As such, establishing an efficient and rapid functional verification system is particularly important. In this study,tobacco rattle virus (TRV) and the phytoene desaturase gene KoPDS were used as the vector and target gene, respectively, to establish a virus-induced gene silencing system (VIGS) in K. obovata. Besides, the system was also used to verify the role of a Chlorophyll a/b binding protein (Cab) gene KoCAB in leaf carbon sequestration of K. obovata. RNA-Seq and qRT-PCR showed that the highest gene-silencing efficiency could reach 90% after 10 days of inoculation and maintain above 80% after 15 days, which was achieved with resuspension buffer at pH 5.8 and Agrobacterium culture at OD600 of 0.4-0.6. Taken together, the TRV-mediated VIGS system established herein is the first genetic analysis tool for mangroves, which may greatly impel functional genomics studies in mangrove plants.