Evaluation For Salt Tolerance And Clone P5CS Gene In Reed Canary Grass (Phalaris Arundinacea L.)

Phalaris arundinacea is a perennial herb, with strong stress resistance and high yield, in Europe and the United States, research it as energy grass. In the present experiment, Using6salt concentration gradients that was0(CK)、50、100、150、200and250mmol/L, we made salt stress treatment to6reed canary grass(Phalaris arundinacea L.) materials in two stages that were seed germination and seedling growth.With determining some physiological and biochemical indexes, including germination rate, shoot length,root length, fresh weight and proline content, chlorophyll and malonaldehyde(MDA) content and protective enzyme activity and so on, observing a series of physiological and biochemical response on salt stress treatment. On the basis of the salt-tolerant identification, select salt-resistant material for the P5CS gene fragment cloning, and in200mmol/L salt treatment, we analysis P5CS gene’expression and proline content in different treat time.Progresses of this researeh as follows:(1) Seed Germination and seedling growth were not significantly affected at lower salt concentration. With the increase of salt concentration, the germination rate, shoot length, root length, fresh weight and chlorophyll content decreased, proline content and SOD activity increased significantly, MDA content decreased a little under low NaCl stress, then increased with increasing of NaCl concentration. Root growth was more sensitive than shoot to salt stress.6accessions showed significantly different salt tolerance level during seed germination, seedling physiological changes, ZxyO6p-2449and Zxy06p-1904were more salt tolerant; Zxy06p-2380and ZxyO6p-2633were intermediate; ZxyO6p-2262and ZxyO6p-1916were more sensitive to salt stress.(2) Partial cDNA of P5CS was isolated from ZxyO6p-2449and registered in NCBI GenBank (GenBank accession No. JQ622685), which encode323amino acid polypeptides, Sequence analysis showed that the P5CS was93%homologous to the wheat’P5CS in nucleotide sequence, and share88%homology with rice’P5CS gene.(3) A451bp cDNA fragment was cloned according to conserved sequence of the Actin homologous genes. In real-time quantitative PCR experiment, we used the Actin as the reference gene to analysis the expression of p5CS.(4) Expression analysis revealed that P5CS transcripts and proline content were up-regulated in leaf while were down-regulated in roots after treatment of seedlings with salt (200mmol/L).In this paper, salt-tolerance of Phalaris arundinacea in seed germination stage and seedling stage were identified, laid the foundation for Phalaris arundinacea salt-tolerance germplasm screening, and P5CS gene cloned from Phalaris arundinacea supply a candidate gene for enhancing tolerance to salinity in breeding crops, Actin gene can be used as the internal reference in the quantitative analysis of the other genes of P. arundinacea.