Kernel and ear traits are key components of grain yield in maize (Zea mays L.). Investigation of these traits would help to develop high-yield varieties in maize. Genome-wide association study (GWAS) uses the linkage disequilibrium (LD) in the whole genome to determine the genes affecting certain phenotype. In this study, five ear traits (kernel length and width, ear length and diameter, cob diameter) were investigated across multi-environments for 2 years. Combining with the genotype obtained from Maize SNP50 chip, genetic diversity and association mapping in a set of 292 inbred lines were performed. Results showed that maize lines were clustered into seven subgroups and a total of 20 SNPs were found to be associated with ear traits significantly (P < 3.95E-05). The candidate genes identified by GWAS mainly encoded ubiquitin-activation enzymes (GRMZM2G015287), carotenoid cleavage dioxygenase (GRMZM2G446858), MYB-CC type transfactor, and phosphate starvation response protein 3, and they were associated with kernel length (KL) and ear diameter (ED), respectively. Moreover, two novel genes corresponding to RNA processing and fructose metabolism were found. Further, the SNPs detected by GWAS were confirmed by meta-QTL analysis. These genes and SNPs identified in the study would offer essential information for yield-related genes clone and breeding program in maize.

Drought is a major yield-limiting factor in maize production. Osmotic stress was applied to two maize inbred lines with polyethylene glycol 6000 treatments. Proteins from the leaves were analyzed by two-dimensional gel electrophoresis and peptide mass fingerprinting at two time points, 24 and 48 h after osmotic stress. Thirty-five proteins were differentially expressed between control and treatment groups in the two maize inbred lines. In ‘Qi319’, a drought-tolerant inbred line, there were five up-regulated proteins at 24 h and 13 up-regulated and one down-regulated protein at 48 h. In drought-sensitive line ‘Zheng58’, 10 proteins were up-regulated at 24 h, while six proteins were up-regulated at 48 h. The 35 proteins were subjected to mass spectrometry and 17 proteins were successfully identified. These proteins were classified into six categories: photosynthesis-related, energy and metabolism, signaling pathways, protein synthesis, defense-related, and unclassified.

The present study analyzed the characteristics and risk factors associated with tracheobronchial tuberculosis (TBTB) in 410 patients with TBTB. Retrospective analysis was performed on the clinical features, bronchoscopy performance, bacteriological examination, imaging and treatment of 410 patients who were diagnosed with TBTB using bronchoscopy. Among the 410 patients, 10 patients underwent chest X-ray which revealed two cases of atelectasis, eight cases of patch or spot shadows, three cases of cavity, one case of nodule and one case with no abnormalities. The remaining 400 patients underwent computed tomography chest scans and/or airway reconstruction examinations. Among all the lesion types, the cavity type was found to be the most likely to cause bronchial stenosis or obstruction, with statistically significant differences when compared with the congestion, stenosis or scar lesion types (P<0.01). Moreover, for the cavity type, there were 194 sites of obstruction prior to therapy; however, only 23 sites of obstruction remained following therapy. Furthermore, there were 34 sites without stenosis prior to therapy and 205 sites without stenosis following therapy. The number of sites of obstruction was significantly decreased and the number of sites without stenosis was increased upon therapy. These findings suggest that the cavity type is the most sensitive type to therapy among the five types of TBTB lesion.

Backgrounds Grain size is a key factor in crop yield that gradually develops after pollination. However, few studies have reported gene expression patterns in maize grain development using large-grain mutants. To investigate the developmental mechanisms of grain size, we analyzed a large-grain mutant, named tc19, at the morphological and transcriptome level at five stages corresponding to days after pollination (DAP). Results After maturation, the grain length, width, and thickness in tc19 were greater than that in Chang7-2 (control) and increased by 3.57, 8.80, and 3.88%, respectively. Further analysis showed that grain width and 100-kernel weight in tc19 was lower than in Chang7-2 at 14 and 21 DAP, but greater than that in Chang7-2 at 28 DAP, indicating that 21 to 28 DAP was the critical stage for kernel width and weight development. For all five stages, the concentrations of auxin and brassinosteroids were significantly higher in tc19 than in Chang7-2. Gibberellin was higher at 7, 14, and 21 DAP, and cytokinin was higher at 21 and 35 DAP, in tc19 than in Chang7-2. Through transcriptome analysis at 14, 21, and 28 DAP, we identified 2987, 2647 and 3209 differentially expressed genes (DEGs) between tc19 and Chang7-2. By using KEGG analysis, 556, 500 and 633 DEGs at 14, 21 and 28 DAP were pathway annotated, respectively, 77 of them are related to plant hormone signal transduction pathway. ARF3, AO2, DWF4 and XTH are higher expressed in tc19 than that in Chang7-2. Conclusions We found some DEGs in maize grain development by using Chang7-2 and a large-grain mutant tc19. These DEGs have potential application value in improving maize performance.