Cloning of HDR gene in Pinus massoniana and its response to drought and salt stresses

Abstract

Drought and land salinization are inhibiting factors for the sustainable development of forestry, and the plants will release volatile substances such as terpenoids during biological or non-biological stress. The 1-hydroxy-2-methyl-2-(E)-buteny-4-pyrophosphate reductase is the terminal active enzyme of the MEP pathway, which provides precursor terpenoids and has the main rate-limiting effect. In order to investigate whether HDR gene of Pinus massoniana is involved in stress response under drought and salt stress, the open reading frame of PmHDR gene was cloned, and bioinformation, tissue specific expression and preliminary function were analyzed. The results were as follows: (1) The coding region length of PmHDR gene is 1 458 bp, encoding 485 amino acids, and its encoded protein contains the core sequence of LytB/IspH gene superfamily and PLN02821 multifunctional structural domain, which belongs to the HDR family. (2) The PmHDR codon use preference was weak, with a preference for codons ending in A/U. Nicotiana tabacum, Arabidopsis thaliana and Saccharomyces cerevisiae were more suitable as its heterologous expression receptors. (3) Results of qRT-PCR showed that the PmHDR gene was most highly expressed in old needles of Pinus massoniana, followed by young needles, young stem and old stem and least expressed in root. (4) The gene expression vector pBI121-PmHDR was constructed and transformed into Arabidopsis thaliana. The transgenic A.thaliana showed greater resistance to drought and salt stress. These results indicate that PmHDR is involved in plant response and regulation to drought and salt stress, and provide some theoretical supports for Pinus massoniana stress-resistance breeding.

Keywords

• pinus massoniana
• pmhdr
• terpenoids
• gene cloning
• stress response