Molecular cloning of potassium transporter gene, MaHAK5 of mulberry (Morus alba L.) and gene expression and biochemistry analysis under potassium stress

Potassium (K +) is one of the many elements necessary for plant growth and development, and is the only one that plants need to have a higher concentration of cation. In order to cope with the low potassium stress, the plant evolves a series of complex signal regulation pathways. HAK5 is an important high-affinity potassium transporter, which is mainly responsible for potassium uptake under low potassium conditions, and low potassium stress can significantly induce transcription of HAK5. In this experiment, the complete reading frame (ORF) of the gene was cloned from the young leaves of mulberry (Morus alba L.) Yu71-1, named MaHAK5.Sequence analysis showed that the MaHAK5 is 2625bp long, it's open reading frame (ORF) is of 2478bp, and encoding 828 amino acids with a predicted molecular weight of 92.17kD and an isoelectric point of 8.37. Phylogenetic analysis based on MaHAK5 with other species showed that mulberry had a closer relationship with Chuansang (Morus notabilis XP_010112002.1), Jujube (Ziziphus jujuba XP_015898221.1), and Fragaria vesca (Fragaria vesca subsp. Vesca XP_004299195.2). Drought, high salt and low temperature stress could affect the expression level ofMaHAK5 gene in mulberry, meanwhile the expression level of MaHAK5 gene was increased and the physiological and biochemical indicators were affected by low potassium treatment.