The Effect of Two Phosphatase AtPAP17 and AtPAP26 Gene-Knock-out on Growth Period Duration and Flowering in Arabidopsis thaliana Plants

The availability of nutrients such as phosphorus in plant, in addition to plant yield increment, could increase growth rate and thus reduce plant growth period. Therefore, identification and overexpression of genes involved in nutrient uptake are the important steps to increase of yield and tolerance to environmental stresses particularly the end seasons stresses. Purple acid phosphatases, one of the most important phosphatase family, play a key role in increasing phosphorus availability in plants. In this study, the effect of knock-out and overexpression of AtPAP17 and AtPAP26 genes (two important members of Arabidopsis thaliana purple acid phosphatase family) on some physiological and phonological traits of Arabidopsis thaliana was investigated under Pi-sufficient (1.25 mM KH2PO4) and Pi-deficient (0 mM KH2PO4) conditions. For this purpose, single and double mutant plants of AtPAP17 and AtPAP26 genes were studied in this research. To confirm the function of mentioned genes in mutant plants, transformed Arabidopsis plants containing the CaMV-35S:AtPAP17 and CaMV-35S:AtPAP26 constructs were studied as overexpressed plants of AtPAP17 and AtPAP26 genes, respectively. The result showed that biomass and phosphorus content of plants increased in single mutant plants as compared to double mutant plants under Pi-sufficient condition. Superiority of single mutant plants as compared to double mutant plants indicated a remarkable contribution of AtPAP17 and AtPAP26 genes in phosphatase compensation network. Our results showed at least one of these genes (AtPAP17 and AtPAP26) activity is essential for increasing phosphorus availability and fast growth in Arabidopsis thaliana. Also, overexpressed plants displayed a significant increase in phosphorus content, flowering percentage, and biomass as compared to WT plants (Col-0). The results of this study showed that AtPAP17 and AtPAP26 genes could be important candidates for developing the plants with high ability of nutrient uptake, especially phosphorus, thereby reducing plant growth period.