1.
Genome-Wide Association Study of 13 Traits in Maize Seedlings under Low Phosphorus Stress.
Wang, QJ, Yuan, Y, Liao, Z, Jiang, Y, Wang, Q, Zhang, L, Gao, S, Wu, F, Li, M, Xie, W, et al
The plant genome. 2019;(3):1-13
Abstract
Low P stress is a global issue for grain production. Significant phenotypic differences were detected among 13 traits in 356 maize lines under P-sufficient and P-deficient conditions. Significant single nucleotide polymorphisms (SNPs) and low-P stress-responsive genes were identified for 13 maize root traits based on a genome-wide association study. Hap5, harboring 12 favorable SNPs, could enhance strong root systems and P absorption under low-P stress. Phosphorus is an essential macronutrient required for normal plant growth and development. Determining the genetic basis of root traits will enhance our understanding of maize's (Zea mays L.) tolerance to low-P stress. Here, we identified significant phenotypic differences for 13 traits in maize seedlings subjected to P-sufficient and P-deficient conditions. Six extremely sensitive and seven low-P stress tolerant inbreds were selected from 356 inbred lines of maize. No significant differences were observed between temperate and tropical-subtropical groups with respect to trait ratios associated with the adaptation to low-P stress. The broad-sense heritability of these traits ranged from relatively moderate (0.59) to high (0.90). Through genome-wide association mapping with 541,575 informative single nucleotide polymorphisms (SNPs), 551, 1140 and 1157 significant SNPs were detected for the 13 traits in 2012, 2016 and both years combined, respectively, along with 23 shared candidate genes, seven of which overlapped with reported quantitative trait loci and genes for low-P stress. Five haplotypes located in candidate gene GRMZM2G009544 were identified; among these, Hap5, harboring 12 favorable SNP alleles, showed significantly greater values for the root traits studied than the other four haplotypes under both experimental conditions. The candidate genes and favorable haplotypes and alleles identified here provide promising resources for genetic studies and molecular breeding for improving tolerance to abiotic stress in maize.
2.
A highly sensitive and specific method for the screening detection of genetically modified organisms based on digital PCR without pretreatment.
Fu, W, Zhu, P, Wang, C, Huang, K, Du, Z, Tian, W, Wang, Q, Wang, H, Xu, W, Zhu, S
Scientific reports. 2015;:12715
Abstract
Digital PCR has developed rapidly since it was first reported in the 1990 s. It was recently reported that an improved method facilitated the detection of genetically modified organisms (GMOs). However, to use this improved method, the samples must be pretreated, which could introduce inaccuracy into the results. In our study, we explored a pretreatment-free digital PCR detection method for the screening for GMOs. We chose the CaMV35s promoter and the NOS terminator as the templates in our assay. To determine the specificity of our method, 9 events of GMOs were collected, including MON810, MON863, TC1507, MIR604, MIR162, GA21, T25, NK603 and Bt176. Moreover, the sensitivity, intra-laboratory and inter-laboratory reproducibility of our detection method were assessed. The results showed that the limit of detection of our method was 0.1%, which was lower than the labeling threshold level of the EU. The specificity and stability among the 9 events were consistent, respectively. The intra-laboratory and inter-laboratory reproducibility were both good. Finally, the perfect fitness for the detection of eight double-blind samples indicated the good practicability of our method. In conclusion, the method in our study would allow more sensitive, specific and stable screening detection of the GMO content of international trading products.