A phosphate transporter from the root endophytic fungus Piriformospora indica plays a role in phosphate transport to the host plant
Authors: Deepak Kumar Deep
Narendra Tuteja
Takshashila Tripathi
Hemant Kumar
Ruby Sharma
Manoj Kumar
Atul Kumar Johri
Vikas Yadav
Ajay Kumar Saxena
Journal: Journal of Biological Chemistry (2010)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Arbuscular mycorrhizal fungi; phosphate transporters; symbiotic interaction; Piriformospora indica; major facilitator superfamily
Affiliations: School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.

Abstract:  Because pure cultures and a stable transformation system are not available for arbuscular mycorrhizal fungi, the role of their phosphate transporters for the symbiotic interaction with the plant up till now could not be studied. Here we report the cloning and the functional analysis of a gene encoding a phosphate transporter (PiPT) from the root endophytic fungus Piriformospora indica, which can be grown axenically. The PiPT polypeptide belongs to the major facilitator superfamily. Homology modeling reveals that PiPT exhibits twelve transmembrane helices divided into two halves connected by a large hydrophilic loop in the middle. The function of the protein encoded by PiPT was confirmed by complementation of a yeast phosphate transporter mutant. The kinetic analysis of PiPT (K(m) 25 mum) reveals that it belongs to the high affinity phosphate transporter family (Pht1). Expression of PiPT was localized to the external hyphae of P. indica colonized with maize plant root, which suggests that external hyphae are the initial site of phosphate uptake from the soil. To understand the physiological role of PiPT, knockdown transformants of the gene were prepared using electroporation and RNA interference. Knockdown transformants transported a significantly lower amount of phosphate to the host plant than wild-type P. indica. Higher amounts of phosphate were found in plants colonized with wild-type P. indica than that of non-colonized and plants colonized with knockdown PiPT P. indica. These observations suggest that PiPT is actively involved in the phosphate transportation and, in turn, P. indica helps improve the nutritional status of the host plant. 

Retracted: No

PubPeer comments:
 1) Figure-1 of doi: 10.1099 mic.0.019869-0 (Year 2009) has been reused in doi:10.1074 jbc.m110.111021 (Year 2010, Figure- 10, truncated version) and doi:10.4161 psb.6.5.15106 (year 2011, Figure-11). 2) Figure 10 of doi:10.1074 jbc.m110.111021 (Year 2010 right panel ) has been reused in doi:10.4161 psb.6.5.15106 (year 2011). 3) Figure 10 panel b) has been resused from Figure-5 (Both doi:10.1074 jbc.m110.111021) 4) Figure-10 s image of Panel c (doi:10.1074 jbc.m110.111021) hs been reused in doi:10.4161 psb.6.5.15106 (year 2011) , 
  This article has been withdrawn by the authors except Ajay Kumar Saxena and Deepak Kumar Deep who could not be contacted. Fig. 5C panel 3 is duplicated in Fig. 10A, b iii. Fig. 10A, a iii is duplicated as Fig. 1 in Microbiology (2009), 155: 780u2013790. Fig. 5C panel 6 is duplicated as Fig. 1A, b ii right, Fig. 10A, a iii is duplicated as Fig. 1A, a ii right, and Fig. 10A, c is duplicated in Fig. 1A, d in Plant Signaling Behavior (2011) 6(5): 723u2013725, respectively representing different experimental conditions. Plant Signaling Behavior as well as Microbiology have replaced and corrected the figures which were overlapping with the JBC figures as mentioned above. Both Plant Signaling Behavior and Microbiology have published a corrigendum related to the respective figures. https: www.sciencedirect.com science article pii S0021925821002301 ,