The cDNA Cloning and Expression Analysis of the Hsp70 Gene from Pyropia guangdongensis

Abstract:

In order to explore the molecular mechanisms of the Hsp70 gene in Pyropia guangdongensis, we have stimulated it with high temperature stresses. The aim was to provide technical references for the cultivation of P. guangdongensis. The full-length of PgHsp70 was obtained by rapid amplification of cDNA ends technical (RACE). On this basis, the expression of PgHsp70 with the different temperature (22℃, 27℃, and 31℃) stresses after 0, 1/6, 1/2, 1, 6, 12, 24, and 36 h were detected using quantitative real-time PCR. The results showed that the full-length cDNA of PgHsp70 was 2004 bp, including an open reading frame (ORF) of 1866 bp, encoding a polypeptide of 621 amino acids. The molecular mass of the deduced amino acid sequence was 67.7 kDa, with an estimated pI of 4.87. The expression of the PgHsp70, as measured by qRT-PCR, can be significantly induced by high-temperature stress. The three kinds of expression profiles for PgHsp70 were similar at different times, and all of them significantly increased first and then reached their maximum levels after one hour, and then dramatically decreased. Compared to the temperature stress of 22℃ and 27℃, the expression of the P. guangdongensis with the 31℃ temperature stress reached the highest level after being challenged for 1 h and was 11-fold higher than the normal. These results suggested that PgHsp70 plays an essential role in response to high-temperature stresses.