Phosphate transporters OsPHT1;9 and OsPHT1;10 are involved in phosphate uptake in rice

Abstract

We characterized the function of two rice phosphate (Pi) transporters: OsPHT1;9 (OsPT9) and OsPHT1;10 (OsPT10). OsPT9 and OsPT10 were expressed in the root epidermis, root hairs and lateral roots, with their expression being specifically induced by Pi starvation. In leaves, expression of the two genes was observed in both mesophyll and vasculature. High-affinity Km values for Pi transport of OsPT9 and OsPT10 were determined by yeast experiments and twoelectrode voltage clamp analysis of anion transport inXenopus oocytes expressing OsPT9 and OsPT10. Pi uptake and Pi concentrations in transgenic plants harbouring overexpressed OsPT9 and OsPT10 were determined by Pi concentration analysis and 33 P-labelled Pi uptake rate analysis. Significantly higher Pi uptake rates in transgenic plants compared with wild-type plants were observed under both high-Pi and low-Pi solution culture conditions. Conversely, although no alterations in Pi concentration were found in OsPT9 or OsPT10 knockdown plants, a significant reduction in Pi concentration in both shoots and roots was observed in double-knockdown plants grown under both high-and low-Pi conditions. Taken together, our results suggest that OsPT9 and OsPT10 redundantly function in Pi uptake.

Roles, Regulation, and Agricultural Application of Plant Phosphate Transporters

“…For example, overexpression of OsPT8 in rice resulted in excessive Pi both in roots and shoots and significant growth suppression as well as other Pi toxic symptoms under the high-Pi conditions (Jia et al, 2011) ( Table 3 ). Similar results were also observed in OsPT2 , OsPT9 , OsPT10 , OsPHR2 , and OsARF12 transgenic plants (Liu et al, 2010; Wang S. et al, 2014; Wang X. et al, 2014) ( Table 3 ). Overexpression of miR399 in Arabidopsis and tomato also caused Pi toxicity and retarded growth (Fujii et al, 2005; Gao et al, 2009).…”

“…The first plant PHT1 gene was cloned from Arabidopsis (Muchhal et al, 1996) and exhibited similarities to genes encoding Pi transporters in Saccharomyces cerevisiae ( PHO84 ; Bun-Ya et al, 1991). Based on protein sequence identity and conserved signature analysis, PHT1 members from several plant species have been identified, including tobacco (Baek et al, 2001), potato (Leggewie et al, 1997; Gordon-Weeks et al, 2003), rice (Paszkowski et al, 2002; Liu et al, 2011; Wang X. et al, 2014; Li et al, 2015), barley (Rae et al, 2003; Preuss et al, 2010, 2011), maize (Liu F. et al, 2016), Medicago truncatula (Javot et al, 2007a; Liu et al, 2008), wheat (Liu et al, 2013), soybean (Fan et al, 2013), Setaria italica (Ceasar et al, 2014), tomato (Chen et al, 2014), sorghum (Walder et al, 2015), flax (Walder et al, 2015), and poplar (Zhang et al, 2016). The numbers of PHT1 members identified in various plants were listed in Table 2 .…”

“…As for group III of PHT1 family, transporters may be involved in Pi uptake as well as Pi allocation from root to shoot, considering the well characterized AtPHT1;8 and AtPHT1;9 (Hamburger, 2002; Lapis-Gaza et al, 2014) and OsPT9 and OsPT10 (Wang X. et al, 2014) in this group. Also, the respective orthologs of AtPHT1;8 and AtPHT1;9 from E. salsugineum were included in this group.…”

Engineering crop nutrient efficiency for sustainable agriculture

“…Another PHT1 transporter, OsPT6, functions broadly in Pi uptake and translocation in the whole plant (Ai et al ), and OsPT8 is critical for maintaining Pi homeostasis throughout plant growth and development (Jia et al ). OsPT9 and OsPT10 function redundantly in P uptake under both high‐P and low‐P conditions (Wang et al ). In wheat, a root‐specific phosphate transporter, TaPT2, mediates P uptake under low‐P conditions, which makes this an interesting candidate gene for improving P use efficiency in cereals (Guo et al ).…”

Expression of four phosphate transporter genes from Finger millet (Eleusine coracana L.) in response to mycorrhizal colonization and Pi stress

“…The past studies have indicated the presence of a mineral transport system in plants that consist of membrane-spanning phosphate transporter family proteins (Pht1 family). The members of this gene family are identified from various plants like Arabidopsis thaliana (Bayle et al 2011; Remy et al 2012), rice (Ai et al 2009; Campos-Soriano et al 2012; Sun et al 2012; Wang et al 2014; Wu et al 2013), wheat (Davies et al 2002; Duan et al 2015; Guo et al 2014), tomato (Chen et al 2014; Liu et al 1998a), tobacco (Tan et al 2012), maize (Nagy et al 2006; Su et al 2014), barley (Schünmann et al 2004), Medicago truncatula (Javot et al 2007; Liu et al 1998b), Populus trichocarpa (Loth-Pereda et al 2011), and soybean (Inoue et al 2014; Song et al 2014). …”