Cloning of three genes involved in the flavonoid metabolic pathway and their expression during insect resistance in Pinus massoniana Lamb.

Pinus massoniana Lamb. is an important timber and turpentine-producing tree species in China. Dendrolimus punctatus and Dasychira axutha are leaf-eating pests that have harmful effects on P. massoniana production. Few studies have focused on the molecular mechanisms underlying pest resistance in P. massoniana. Based on sequencing analysis of the transcriptomes of insect-resistant P. massoniana, three key genes involved in the flavonoid metabolic pathway were identified in the present study (PmF3H, PmF3'5'H, and PmC4H). Structural domain analysis showed that the PmF3H gene contains typical binding sites for the 2OG-Fe (II) oxygenase superfamily, while PmF3'5'H and PmC4H both contain the cytochrome P450 structural domain, which is specific for P450 enzymes. Phylogenetic analysis showed that each of the three P. massoniana genes, and the homologous genes in gymnosperms, clustered into a group. Expression of these three genes was highest in the stems, and was higher in the insect-resistant P. massoniana varieties than in the controls. The extent of the increased expression in the insect-resistant P. massoniana varieties indicated that these three genes are involved in defense mechanisms against pests in this species. In the insect-resistant varieties, rapid induction of PmF3H increased the levels of PmF3'5'H and PmC4H expression. The enhanced anti-pest capability of the insect-resistant varieties could be related to temperature and humidity. In addition, these results suggest that these three genes maycontribute to the change in flower color during female cone development.

Development and characterization of SSR markers from Pinus massoniana and their transferability to P. elliottii, P. caribaea and P. yunnanensis.

Pinus massoniana (Masson's pine) is a widespread tree species in central and southern China and northern Vietnam; it is valued for rosin and paper production. Despite the significant economic value of Masson's pine, little work has been done on its molecular genetics. We developed 318 SSR primers from genome sequences of P. massoniana, and we identified 10 polymorphic markers. The number of alleles in the population of P. massoniana that we examined ranged from two to four, and the Shannon diversity index ranged from 0.150 to 1.133. Cross-species transferability of the 318 SSRs was also analyzed in the slash pine (Pinus elliottii), the Caribbean pine (Pinus caribaea) and the Yunnan pine (Pinus yunnanensis); 15, 10, and 10 primer pairs generated polymorphic amplification, respectively. These sets of polymorphic SSR markers will be useful for population genetics studies of P. massoniana, for genetic identification of interspecific hybridization, and for phylogeographic studies of Pinus spp.

Relationship between multidrug resistance 1 polymorphisms and the risk of prostate cancer in Chinese populations.

Prostate cancer is one of the most common malignancies in men. The multidrug resistance 1 gene (MDR1) is an important candidate gene for prostate cancer. The aim of this study was to evaluate the association between MDR1 gene polymorphisms and the risk of prostate cancer. MDR1 gene polymorphism and its association with the risk of prostate cancer were investigated in 357 Chinese men. A novel c.1465C>T polymorphism was detected with created restriction site-polymerase chain reaction and DNA sequencing. We found a significantly increased risk of prostate cancer in the homozygote comparison [TT vs CC: odds ratio (OR) = 2.300, 95% confidence interval (95%CI) = 1.261-4.196, chi-square = 7.53, P = 0.007], heterozygote comparison (TC vs CC: OR = 1.667, 95%CI = 1.049-2.648, chi-square = 4.71, P = 0.030), dominant model (TT/TC vs CC: OR = 1.835, 95%CI = 1.197-2.815, chi-square = 7.81, P = 0.005), recessive model (TT vs TC/CC: OR = 1.776, 95%CI = 1.023- 3.085, chi-square = 4.23, P = 0.041), and allele contrast (T vs C: OR = 1.625, 95%CI = 1.199-2.202, chi-square = 9.87, P = 0.002). These findings suggested that the c.1465C>T polymorphism of MDR1 may be risk factors for prostate cancer in Chinese men.