Functional analysis of the novel mycorrhiza‐specific phosphate transporter AsPT1 and PHT1 family from Astragalus sinicus during the arbuscular mycorrhizal symbiosis. Issue 3 (27th February 2013)

• Record Type: Journal Article
• Authors: Xie, Xianan; Huang, Wu; Liu, Fengchuan; Tang, Nianwu; Liu, Yi; Lin, Hui; Zhao, Bin
• Is Part Of: New phytologist. Volume 198:Issue 3(2013)
• Page Start: 836
• Page End: 852
• Publication Date: 2013-02-27
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12188
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12188-abs-0001"> <title>Summary</title> <p> <list id="nph12188-list-0001" list-type="bullet"> <list-item> <p>Arbuscular mycorrhizas contribute significantly to inorganic phosphate (Pi) uptake in plants. Gene networks involved in the regulation and function of the Pht1 family transporters in legume species during AM symbiosis are not fully understood.</p> </list-item> <list-item> <p>In order to characterize the six distinct members of Pht1 transporters in mycorrhizal <italic>Astragalus sinicus</italic>, we combined cellular localization, heterologous functional expression in yeast with expression/subcellular localization studies and reverse genetics approaches in planta. <italic>Pht1;1</italic> and <italic>Pht1;4</italic> silenced lines were generated to uncover the role of the newly discovered dependence of the AM symbiosis on another phosphate transporter AsPT1 besides AsPT4.</p> </list-item> <list-item> <p>These Pht1 transporters are triggered in Pi‐starved mycorrhizal roots. <italic>AsPT1</italic> and <italic>AsPT4</italic> were localized in arbuscule‐containing cells of the cortex. The analysis of promoter sequences revealed conserved motifs in both <italic>AsPT1</italic> and <italic>AsPT4</italic>. <italic>AsPT1</italic> overexpression showed higher mycorrhization levels than controls for parameters analysed, including abundance of arbuscules. By contrast, knockdown of <italic>AsPT1</italic> by RNA interference led to degenerating or dead arbuscule phenotypes identical to that of <italic>AsPT4</italic> silencing lines. <italic>AsPT4</italic> but not <italic>AsPT1</italic> is required for symbiotic Pi uptake.</p> </list-item> <list-item> <p>These results suggest that both, AsPT1 and AsPT4, are required for the AM symbiosis, most importantly, AsPT1 may serve as a novel symbiotic transporter for AM development.</p> </list-item> </list> </p> </abstract>