Research on remote sensing classification of fruit trees based on Sentinel-2 multi-temporal imageries.

Accurately obtaining the spatial distribution information of fruit tree planting is of great significance to the development of fruit tree growth monitoring, disease and pest control, and yield estimation. In this study, the Sentenel-2 multispectral remote sensing imageries of different months during the growth period of the fruit trees were used as the data source, and single month vegetation indices, accumulated monthly vegetation indices (∑VIs), and difference vegetation indices between adjacent months (∆VIs) were constructed as input variables. Four conventional vegetation indices of NDVI, PSRI, GNDVI, and RVI and four improved vegetation indices of NDVIre1, NDVIre2, NDVIre3, and NDVIre4 based on the red-edge band were selected to construct a decision tree classification model combined with machine learning technology. Through the analysis of vegetation indices under different treatments and different months, combined with the attribute of Feature_importances_, the vegetation indices of different periods with high contribution were selected as input features, and the Max_depth values of the decision tree model were determined by the hyperparameter learning curve. The results have shown that when the Max_depth value of the decision tree model of the vegetation indices under the three treatments was 6, 8, and 8, the model classification was the best. The accuracy of the three vegetation index processing models on the training set were 0.8936, 0.9153, and 0.8887, and the accuracy on the test set were 0.8355, 0.7611, and 0.7940, respectively. This method could be applied to remote sensing classification of fruit trees in a large area, and could provide effective technical means for monitoring fruit tree planting areas with medium and high resolution remote sensing imageries.

A novel glutathione S-transferase gene from sweetpotato, IbGSTF4, is involved in anthocyanin sequestration.

Anthocyanins are synthesized by multi-enzyme complexes localized at the cytoplasmic surface of the endoplasmic reticulum (synthesis site), and transported to the destination site, the vacuole. Three mechanisms for the vacuolar accumulation of anthocyanin in plant species have been proposed. Previous studies have indicated that glutathione S-transferase (GST) genes from model and ornamental plants are involved in anthocyanin transportation. In the present study, an anthocyanin-related GST, IbGSTF4, was identified and characterized based on transcriptome results. Phylogenetic analysis revealed that IbGSTF4 was most closely correlated to PhAN9 and CkmGST3, the anthocyanin-related GST of Petunia hybrida and Cyclamen. Furthermore, the expression analysis revealed that IbGSTF4 is strongly expressed in pigmented tissues, when compared to green organs, which is in agreement to the ability to correlate with anthocyanin accumulation. A GST activity assay uncovered that the IbGST4 protein owned similar activities with the GST family. Furthermore, the molecular functional complementation of Arabidopsis thaliana mutant tt19 demonstrated that IbGSTF4 might play a vital role in the vacuole sequestration of anthocyanin in sweetpotato. Moreover, the dual luciferase assay revealed that the LUC driven by the promoter of IbGSTF4 could not be directly activated by IbMYB1, suggesting that the regulatory mechanism of anthocyanin accumulation and sequestration in sweetpotato was intricate.

Cloning and characterization of a novel GIGANTEA gene in sweet potato.

The transition from vegetative to reproductive growth, a key event in the lifecycle of a plant, is affected by environmental stresses. The flowering-time regulator GIGANTEA (GI) may be contributing to susceptibility of the regulation of photoperiodic flowering, circadian rhythm control, and abiotic stress resistance in Arabidopsis. However, the role of GI in sweet potato remains unknown. Here, we isolated and characterized a GI gene (IbGI) from sweet potato (Ipomoea batatas [L.] Lam). The IbGI cDNA sequence was isolated based on information from a sweet potato transcriptome database. IbGI mRNA transcript levels showed robust circadian rhythm control during the light-dark transition, and the expression of IbGI was stronger in leaves and roots than in stems. IbGI protein is predominantly localized to the nucleus. IbGI expression was upregulated by high temperature, drought, and salt stress but downregulated by cold stress. Overexpressing IbGI in the Arabidopsis gi-2 mutant background rescued its late flowering phenotype and reduced its salt tolerance. Taken together, these results indicate that IbGI shares functions in regulating flowering, the circadian rhythm, and tolerance to some stresses with other GI orthologs.

Overexpression of CuZnSOD and APX enhance salt stress tolerance in sweet potato.

Abiotic stresses cause accumulation of reactive oxygen species (ROS) in plants, CuZnSOD and APX are first line defenses against ROS caused by oxidative stress. In this study, CuZnSOD and APX were transferred into salt sensitive sweet potato (cv. Xushu 55-2) under control of stress inducible SWPA2 promoter and tolerance to salt stress was evaluated. When 100 mM NaCl was used to treat stem cuttings, transgenic plants showed enhanced tolerance compared to wild type (WT) plants. Rooting was significantly retarded in WT plants whereas all transgenic plants had significantly enhanced root growth under salt stress. Integration of SOD gene was confirmed by southern blot analysis, and the copy number ranged from 1 to 3. The expression levels of CuZnSOD and APX in transgenic plants were significantly increased up to 13.3 and 7.8 folds to WT under salinity conditions, respectively. SOD and APX activity and ROS staining showed enzyme activities of transgenic plants were increased under salt stress. These results show that CuZnSOD and APX have important roles in enhancing the salt tolerance of sweet potato.

[Establishment and Verification of 6-color Fluorescent-labeled Rapid PCR Amplification System].

OBJECTIVE: To establish the rapid PCR amplification program and system and to verify the technical indexes. METHODS: PCR multiplex and capillary electrophoresis detection of 24 autosomal STR loci and one Y-STR loci using the 6-color fluorescence marking technology, as well as A melogenin and Y-InDel. Meanwhile, sensitivity, specificity, identity, stability, mixing and a batch of sample tests were investigated, and the genotype of various routine samples and degraded, exfoliated cell samples were observed. RESULTS: The sensitivity of the system was 0.062 5 ng. In addition, the genotype could be detected accurately only around 65 min via rapid amplification. The species-specificity was high and the genotyping of all kinds of dry blood specimens of filter paper and mixed, degraded, exfoliated cell samples were accurate. CONCLUSION: The rapid amplification system can significantly improve the detection rate, and obtain accurate and stable genotyping results, which may be important implications for the establishment of STR database and study on population genetics and forensic identification.

Engineering OsBAK1 gene as a molecular tool to improve rice architecture for high yield.

Generating a new variety of plant with erect-leaf is a critical strategy to improve rice grain yield, as plants with this trait can be dense-planted. The erect-leaf is a significant morphological trait partially regulated by Brassinosteroids (BRs) in rice plants. So far, only a few genes can be used for molecular breeding in rice. Here, we identified OsBAK1 as a potential gene to alter rice architecture. Based on rice genome sequences, four closely related homologs of Arabidopsis BAK1 (AtBAK1) gene were amplified. Phylogenetic analysis and suppression of a weak Arabidopsis mutant bri1-5 indicated that OsBAK1 (Os08g0174700) is the closest relative of AtBAK1. Genetic, physiological, and biochemical analyses all suggest that the function of OsBAK1 is conserved with AtBAK1. Overexpression of a truncated intracellular domain of OsBAK1, but not the extracellular domain of OsBAK1, resulted in a dwarfed phenotype, similar to the rice BR-insensitive mutant plants. The expression of OsBAK1 changed important agricultural traits of rice such as plant height, leaf erectness, grain morphologic features, and disease resistance responses. Our results suggested that a new rice variety with erect-leaf and normal reproduction can be generated simply by suppressing the expression level of OsBAK1. Therefore, OsBAK1 is a potential molecular breeding tool for improving rice grain yield by modifying rice architecture.

No association between vitamin D receptor polymorphisms and coronary artery disease in a Chinese population.

The clinical features suggest that genetic factors may have a strong influence on susceptibility to coronary artery disease (CAD). The aim of this study was to investigate the association between FokI (rs2228570) and BsmI (rs1544410) of the vitamin D receptor (VDR) gene polymorphisms and patients with CAD in a Chinese population. One hundred and fifty-two CAD patients and 212 healthy controls were genotyped for the FokI and BsmI polymorphisms in VDR gene using polymerase chain reaction-restriction fragment length polymorphism. No significant differences were observed in the genotype and allele frequencies of the FokI and BsmI polymorphisms between the cases and controls (For FokI: odds ratio = 1.11, 95% confidence interval 0.83-1.50; for BsmI: odds ratio = 0.74, 95% confidence interval 0.44-1.23). There was no significant difference in the genotype distribution or the allele frequencies of VDR FokI and BsmI between two groups in a Chinese population.