Identification and expression analysis of theHevea brasiliensisphosphate transporter 1 gene family

摘要

Key message TwelveHbPHT1swere identified inHeveaand most of them were induced by phosphate starvation. HbPHT1;5 complemented the defective yeast mutant strain EY917 and HbPHT1;7 only partly complemented it. Phosphorus is an important element of the latex of rubber tree, and its content affects the quality and yield of latex. However, with the outflow of latex, a large amount of phosphorus is lost. The phosphate transporter 1 (PHT1) family proteins regulate the phosphorus acquisition and translocation in the plants, but their expression and roles inHevea brasiliensisremain unclear. In this work, we identified twelveHbPHT1s (HbPHT1;1toHbPHT1;12). Evolutionary analyses suggested two duplication events:HbPHT1;5/HbPHT1;6andHbPHT1;7/HbPHT1;8. In the promoter region of someHbPHT1s, there existed P1BS, W-box, MYB, and ethylene responsecis-elements. All theHbPHT1s, except forHbPHT1;4, were expressed in the roots, and most of them were also expressed in the stems and leaves.HbPHT1;7had the highest expression level in the roots, stems, and leaves.HbPHT1;5andHbPHT1;6had a relatively higher expression levels than other genes in latex.HbPHT1;5,HbPHT1;7, andHbPHT1;11were induced by ethylene treatment. MostHbPHT1swere induced under phosphate starvation conditions in the seedling leaves, and the expression ofHbPHT1;9was 20-fold higher than the control.HbPHT1;5complemented the deficiency of the yeast mutant strain EY917 in phosphate transportation under low- and high-phosphate conditions, andHbPHT1;7restored the deficiency when 10 mM phosphate was supplied. These results suggested that the increased expression of PHT1s may improve the phosphate uptake, transport, and utilization inHevea. It also provides the basis to sudy the phosphorus metabolism network and mine the gene resources for the genetic breeding ofHevea.