Study On Physiological Characteristics And The Transcriptome Of Enteromorpha Prolifera

Enteromorpha prolifera as an important ecological macroalge, which lives in the upper zone of the intertidal zone so that it inherently face large and rapid changes in environments including temperature light intensity and osmosis pressure. In this article, we took several familiar environmental factors on the Enteromorpha prolifera to observe its spore propagation. It was proved that proper environmental mence could urge the spore release. Besides, we characterize the transcriptome of Enteromorpha prolifera by high-throughput sequencing technology with the aim to provide the molecular evidence for its unique characteristic in physiology and ecology. The main results as following:1. It was proved that proper environmental mence could urge the spore release,but the effects of different factors were diverse. Salinity stimulated the spore release markedly, and low salinity can stimulate more obviously than the high. When the salinity fell from 30‰to 10‰the number of released spores was the largest. Moreover, temperature, rehydration after desiccation and fragmentation were all able to facilitate the spore release. The result showed that spore propagation was efficacious to adapt the environmental mence. It also provided evidence to study the green tide provenance of Enteromorpha prolifera. Besides, it was revelatory to study the outbreak mechanism of Enteromorpha prolifera and control the Enteromorpha prolifera green tide.2. After the investigations on several ecological factors of spore germination and growth of Enteromorpha prolifera, the suitable ranges and the optimum ranges of each factor have been confirmed. According to our study, the suitable salinity, light intensity and temperature ranges for spore germination are 10～40‰, 20～80μmol m-2 s-1and 10～28℃, and growth are 10～40‰, 20～80μmol m-2 s-1and 10～24℃.3. In the article, we characterize the transcriptome of Enteromorpha prolifera by high-throughput sequencing technology with the aim to provide the molecular evidence for its unique characteristic in physiology and ecology. In sum, there are about 29,370,732 readers of high quality generated, which consists of 2,202,804,900 base pairs. After assembly we obtained 52,446 scaffolds-genes, which include 33,631 unigenes. We subjected all of the scaffolds-genes to the public database for annotation and classification. The classification of COG showed that the scaffolds-genes which have significant hit against the COG database are grouped into 7 categories. It is observed that there are expression of many genes involved in the fixation of carbon dioxide including the genes participating in the C3 pathway, genes driving the C4 pathway and genes related to the CCM(CO2 concentrating mechanism). Furthermore, we have detected the expression of genes which are associated with the components and movement of flagellar. Finally, genes involved in the adaptation to the abiotic stress such as the genes related to the synthesis of proline, genes related to the synthesis of trehalose, genes related to tolerance against high light and genes related to ROS have been identified. The analysis towards these genes can provide the molecular evidence for its unique characteristic in ecology and physiology.