Mining genes involved in the stratification of Paris polyphylla seeds using high-throughput embryo transcriptome sequencing.

BACKGROUND: Paris polyphylla var. yunnanensis is an important medicinal plant. Seed dormancy is one of the main factors restricting artificial cultivation. The molecular mechanisms of seed dormancy remain unclear, and little genomic or transcriptome data are available for this plant. RESULTS: In this study, massive parallel pyrosequencing on the Roche 454-GS FLX Titanium platform was used to generate a substantial sequence dataset for the P. polyphylla embryo. 369,496 high quality reads were obtained, ranging from 50 to 1146 bp, with a mean of 219 bp. These reads were assembled into 47,768 unigenes, which included 16,069 contigs and 31,699 singletons. Using BLASTX searches of public databases, 15,757 (32.3%) unique transcripts were identified. Gene Ontology and Cluster of Orthologous Groups of proteins annotations revealed that these transcripts were broadly representative of the P. polyphylla embryo transcriptome. The Kyoto Encyclopedia of Genes and Genomes assigned 5961 of the unique sequences to specific metabolic pathways. Relative expression levels analysis showed that eleven phytohormone-related genes and five other genes have different expression patterns in the embryo and endosperm in the seed stratification process. CONCLUSIONS: Gene annotation and quantitative RT-PCR expression analysis identified 464 transcripts that may be involved in phytohormone catabolism and biosynthesis, hormone signal, seed dormancy, seed maturation, cell wall growth and circadian rhythms. In particular, the relative expression analysis of sixteen genes (CYP707A, NCED, GA20ox2, GA20ox3, ABI2, PP2C, ARP3, ARP7, IAAH, IAAS, BRRK, DRM, ELF1, ELF2, SFR6, and SUS) in embryo and endosperm and at two temperatures indicated that these related genes may be candidates for clarifying the molecular basis of seed dormancy in P. polyphlla var. yunnanensis.

[Relation between soil nutrient of artificially cultivated area and rhizome quality of Paris polyphylla var. yunnanensis].

OBJECTIVE: To explore the relation between the quality of the Herb-Paris and their cultivation of soil nutritional status. METHODS: The soil nutrient status (0 - 30 cm) of Paris polyphylla var. yunnanensis, artificially cultivated areas were determined in 2009 and their rhizome qualities harvested in 2010 were evaluated respectively. Determination of 0 - 30cm depth soil ingredients status with soil conventional five nutritional analysis method of 29 artificial cultivation area, 9 Prefectures of Yunnan Province. RESULTS: Soil nutrient has effect on quality of Herb-Paris medicinal ingredients. CONCLUSION: The multiple linear stepwise regression analysis reveals that among a certain range, the steroidal saponin VII content is positively correlated with the content of soil organic matter and pH. Steroidal saponin H content is positively correlated with the content of soil organic matter, available P and pH. Steroidal saponin I is positively correlated with the content of available K, but negatively correlated with the content of available Herb-Paris, and steroidal saponin II is positively correlated with the content of soil organic matter and available K.

[Investigation of Paris genus resources in Xishuangbanna].

OBJECTIVE: To explore the species, distributing and resource of Paris genus plants in Xishuangbanna area of Yunnan province. METHOD: Two steps, talking with the folk doctors and field survey, were employed to explore the resource status of Paris plants. Twenty six villages and towns, which are at an elevation of 500 m to 2000 m, were investigated. RESULT: A total of 214 specimens were collected and identified according to morphological characteristics. All investigated spots had Paris genus resources distribution but there always had a small Paris population less than 20. The Paris genus is an understory plants which lives always in a specific environment beside creek in hill valley and with many commensal plants such as bamboo and broadleaf. Three species of Paris, P. polyphylla var. yunnanensis, P. polyphylla var. chinensis, and P. vietnamensis were collected and identified. CONCLUSION: Paris genus resources declined rapidly in recent year, particular the P. polyphylla var. yunnanensis. Developing the breeding and cultivation technologies and enhancing the resources protection are needed urgently.