[Pollution Levels, Sources, and Spatial Distribution of Phthalate Esters in Soils of the West Lake Scenic Area].

To investigate pollution from phthalate esters (PAEs) in the soils of the West Lake Scenic Area, Hangzhou, Zhejiang province, a total of 42 samples were collected from 4 species of soil with different uses. The concentrations and composition of 6 PAEs were analyzed by gas chromatography triple quadrupole mass spectrometry (GC-MS/MS). The sources and spatial distribution of PAEs in the different soil species were analyzed using Principal Component Analysis (PCA) and Ordinary Kriging (OK) methods. It was found that the total concentrations of the 6 PAEs (ΣPAEs) ranged from 597.6 µg·kg-1 to 7360.1 µg·kg-1, of which Dimethyl Phthalate (DMP), Di-n-buthyl Phthalate (DBP), and Di-(2-ethylhexyl) Phthalate (DEHP) were most abundant (98.43% of ΣPAEs). As major pollutant, DEHP contributed as much as 66.28% to ΣPAEs. The composition of PAEs in different soil species differed due to source differences; transportation and tourist activities were the main sources of these PAEs. The 6 PAEs were mainly distributed in the northwestern portion of the West Lake Scenic Area, decreasing from north to south and from east to west.

Construction and evaluation of normalized cDNA libraries enriched with full-length sequences for rapid discovery of new genes from Sisal (Agave sisalana Perr.) different developmental stages.

To provide a resource of sisal-specific expressed sequence data and facilitate this powerful approach in new gene research, the preparation of normalized cDNA libraries enriched with full-length sequences is necessary. Four libraries were produced with RNA pooled from Agave sisalana multiple tissues to increase efficiency of normalization and maximize the number of independent genes by SMART™ method and the duplex-specific nuclease (DSN). This procedure kept the proportion of full-length cDNAs in the subtracted/normalized libraries and dramatically enhanced the discovery of new genes. Sequencing of 3875 cDNA clones of libraries revealed 3320 unigenes with an average insert length about 1.2 kb, indicating that the non-redundancy of libraries was about 85.7%. These unigene functions were predicted by comparing their sequences to functional domain databases and extensively annotated with Gene Ontology (GO) terms. Comparative analysis of sisal unigenes and other plant genomes revealed that four putative MADS-box genes and knotted-like homeobox (knox) gene were obtained from a total of 1162 full-length transcripts. Furthermore, real-time PCR showed that the characteristics of their transcripts mainly depended on the tight expression regulation of a number of genes during the leaf and flower development. Analysis of individual library sequence data indicated that the pooled-tissue approach was highly effective in discovering new genes and preparing libraries for efficient deep sequencing.