Effects of Nitrogen Level during Seed Production on Wheat Seed Vigor and Seedling Establishment at the Transcriptome Level

Nitrogen fertilizer is a critical determinant of grain yield and seed quality in wheat. However, the mechanism of nitrogen level during seed production affecting wheat seed vigor and seedling establishment at the transcriptome level remains unknown. Here, we report that wheat seeds produced under different nitrogen levels (N0, N168, N240, and N300) showed significant differences in seed vigor and seedling establishment. In grain yield and seed vigor, N0 and N240 treatments showed the minimum and maximum, respectively. Subsequently, we used RNA-seq to analyze the transcriptomes of seeds and seedlings under N0 and N240 at the early stage of seedling establishment. Gene Ontology (GO) term enrichment analysis revealed that dioxygenase-activity-related genes were dramatically upregulated in faster growing seedlings. Among these genes, the top three involved linoleate 9S-lipoxygenase (Traes_2DL_D4BCDAA76, Traes_2DL_CE85DC5C0, and Traes_2DL_B5B62EE11). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that pathways involved in nutrient mobilization and the antioxidant system showed enhanced expression under N240. Moreover, seeds with faster growing seedlings had a higher gene expression level of α-amylase, which was consistent with α-amylase activity. Taken together, we propose a model for seedling establishment and seed vigor in response to nitrogen level during seed production

Universal Multiplex PCR: a novel method of simultaneous amplification of multiple DNA fragments

<p>Abstract</p> <p>Background</p> <p>Multiplex PCR has been successfully applied in many areas since it was first reported in 1988; however, it suffers from poor universality.</p> <p>Results</p> <p>A novel method called Universal Multiplex PCR (UM-PCR) was created, which simultaneously amplifies multiple target fragments from genomic DNA. The method has two steps. First, the universal adapter-F and universal adapter-R are connected to the forward primers and the reverse primers, respectively. Hairpin structures and cross dimers of five pairs of adapter-primers are detected. Second, UM-PCR amplification is implemented using a novel PCR procedure termed “Two Rounds Mode” (three and 28–32 cycles). The first round (the first three cycles) is named the “One by One Annealing Round”. The second round (28–32 cycles) combines annealing with extension. In the first two cycles of the first round, primers only amplify the specific templates; there are no templates for the universal adapters. The templates of universal adapters begin to be synthesized from the second cycle of the first round, and universal adapters and primers commence full amplification from the third cycle of the first round.</p> <p>Conclusions</p> <p>UM-PCR greatly improves the universality of multiplex PCR. UM-PCR could rapidly detect the genetic purity of maize seeds. In addition, it could be applied in other areas, such as analysis of polymorphisms, quantitative assays and identifications of species.</p

Dynamic Changes in Seed Germination under Low-Temperature Stress in Maize

Low-temperature stress delays seed germination in maize. Different maize inbred lines display various low-temperature resistance, but the dynamic changes in seed germination under low-temperature stress in maize remain unknown, especially at the transcriptome level. In this study, low-temperature-resistant maize (RM) inbred line 04Qun0522-1-1 had a significantly faster germination speed than low-temperature-sensitive maize (SM) line B283-1 under low-temperature stress. Moreover, the total antioxidant capacity, superoxide dismutase, and peroxidase activities were notably higher in the RM line than in the SM line from 3 to 6 d. In contrast, the SM line showed significantly higher malondialdehyde (MDA) content than the RM line at 6 d. Gene ontology (GO) enrichment analysis showed that in 2dvs0d, both SM and RM lines displayed the downregulation of ribosome-related genes. Moreover, photosystem II and heat shock protein binding-related genes were also downregulated in the SM line. In 4dvs2d, the RM line showed a higher degree of upregulation of the ribosome and peroxidase (POD)-related genes than the SM line. In 6dvs4d, POD-related genes were continuously upregulated in both SM and RM lines, but the degree of upregulation of the genes was higher in the SM line than in the RM line. Moreover, vitamin B6-related genes were specifically upregulated in the RM line. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that in 6dvs4d, phenylpropanoid biosynthesis was the most significantly enriched pathway in both SM and RM lines. Moreover, phenylpropanoid biosynthesis was also enriched in the RM line in 4dvs2d. More than half of the differentially expressed genes (DEGs) in phenylpropanoid biosynthesis were peroxidase, and the DEGs were similar to the GO enrichment analysis. The results provide new insights into maize seed germination in response to low-temperature stress

Amusia and cognitive deficits in schizophrenia : is there a relationship?

The current study explored the music perception ability of individuals diagnosed with schizophrenia and its relationship with other cognitive abilities and psychotic symptom severity. The persons with schizophrenia performed significantly worse than the control group on the Montreal Battery of Evaluation of Amusia (MBEA) (p<. 0.001). The music perception ability of persons with schizophrenia was related to other cognitive abilities (attention, verbal memory, spatial memory, and executive function) and the severity of psychotic symptoms.3 page(s

Characterization of the complete mitochondrial genome of Epipedocera atra Pic (Cerambycidae: Cerambycinae: Tillomorphini)

Epipedocera atra is a common species of Epipedocera Chevrolat which distributed in South China and some countries in Southeast Asia. The complete mitochondria genome of E. atra was 15,662 bp in length, with 37 genes, including 13 protein-coding genes (PCGs), 22 tRNA genes (tRNAs), and 2 rRNA genes (rRNAs). The nucleotide composition was highly A + T biased, accounting for 70.34% of the whole mitogenome. Phylogenetic analysis indicated that E. atra had a close relationship with Xylotrechus grayii White

Seasonal water use strategy of canopy tree species and possible implication for their coexistence in a subtropical secondary forest

We investigated the seasonal water use patterns of five canopy tree species, Schima superba, Liquidambar formosana Hance, Quercus griffithii Hook, Quercus acutissima Carruth, and Pinus massoniana, in a subtropical secondary forest in Guangxi province, which were pervasively planted in South China. The hypothesis is that the trees can make different temporal use of environmental resources that change seasonally and consequently contribute to their coexistence. Sap flow technique was used to measure the daily and seasonal transpiration during the period from June 2016 to May 2017. The sap flow-derived daily transpiration (E-L), leaf water potential (Delta psi), hydraulic conductance (K), as well as the responses of E-L to driving factor-water vapour pressure deficit (VPD) was determined in dry and wet seasons. Measured data of stem sap flow showed that L. formosana, Q. griffithii, and P. massoniana transpired more water than S. superba and Q. acutissima during the whole monitoring period, whereas daily E-L of P. massoniana rapidly decreased under dry season. We attributed the different water use patterns to the significant difference in Delta psi, K, and wood density among the five species. Moreover, linear relationships between the daily transpiration and VPD might suggest diverse water use strategies. For the species of S. superba, Q. acutissima, and P. massoniana, less water consumption and relatively flat change of transpiration with VPD were observed, suggesting a relatively tighter stomatal control. The slope values for L. formosana and Q. griffithii, which were much higher even under dry season, might own a weak stomatal control. These different functional and hydraulic traits, together with the associated water use strategies, might facilitate the coexistence of these five canopy tree species, which would assist in predicting the impact of future environmental changes on plant biodiversity and ecosystem services in the investigated region

Using Field Spectroradiometer to Estimate the Leaf N/P Ratio of Mixed Forest in a Karst Area of Southern China: A Combined Model to Overcome Overfitting

The ratio between nitrogen and phosphorus (N/P) in plant leaves has been widely used to assess the availability of nutrients. However, it is challenging to rapidly and accurately estimate the leaf N/P ratio, especially for mixed forest. In this study, we collected 301 samples from nine typical karst areas in Guangxi Province during the growing season of 2018 to 2020. We then utilized five models (partial least squares regression (PLSR), backpropagation neural network (BPNN), general regression neural network (GRNN), PLSR+BPNN, and PLSR+GRNN) to estimate the leaf N/P ratio of plants based on these samples. We also applied the fractional differentiation to extract additional information from the original spectra of each sample. The results showed that the average leaf N/P ratio of plants was 17.97. Plant growth was primarily limited by phosphorus in these karst areas. The sensitive spectra to estimate leaf N/P ratio had wavelengths ranging from 400–730 nm. The prediction capabilities of these five models can be ranked in descending order as PLSR+GRNN, PLSR+BPNN, PLSR, GRNN, and BPNN when considering both accuracy and robustness. The PLSR+GRNN model yielded high R2 and performance to deviation (RPD), and low root mean squared error (RMSE) with values of 0.91, 3.15, and 1.98, respectively, for the training test and 0.81, 2.25, and 2.46, respectively, for validation test. Compared with the PLSR model, both PLSR+BPNN and PLSR+GRNN models had higher accuracy and were more stable. Moreover, both PLSR+BPNN and PLSR+GRNN models overcame the issue of overfitting, which occurs when a single model is used to predict leaf N/P ratio. Therefore, both PLSR+BPNN and PLSR+GRNN models can be used to predict the leaf N/P ratio of plants in karst areas. Fractional differentiation is a promising spectral preprocessing technique that can improve the accuracy of models. We conclude that the leaf N/P ratio of mixed forest can be effectively estimated using combined models based on field spectroradiometer data in karst areas

Effects of Nitrogen Level during Seed Production on Wheat Seed Vigor and Seedling Establishment at the Transcriptome Level

Nitrogen fertilizer is a critical determinant of grain yield and seed quality in wheat. However, the mechanism of nitrogen level during seed production affecting wheat seed vigor and seedling establishment at the transcriptome level remains unknown. Here, we report that wheat seeds produced under different nitrogen levels (N0, N168, N240, and N300) showed significant differences in seed vigor and seedling establishment. In grain yield and seed vigor, N0 and N240 treatments showed the minimum and maximum, respectively. Subsequently, we used RNA-seq to analyze the transcriptomes of seeds and seedlings under N0 and N240 at the early stage of seedling establishment. Gene Ontology (GO) term enrichment analysis revealed that dioxygenase-activity-related genes were dramatically upregulated in faster growing seedlings. Among these genes, the top three involved linoleate 9S-lipoxygenase (Traes_2DL_D4BCDAA76, Traes_2DL_CE85DC5C0, and Traes_2DL_B5B62EE11). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that pathways involved in nutrient mobilization and the antioxidant system showed enhanced expression under N240. Moreover, seeds with faster growing seedlings had a higher gene expression level of &#945;-amylase, which was consistent with &#945;-amylase activity. Taken together, we propose a model for seedling establishment and seed vigor in response to nitrogen level during seed production