Record ID No. |
1451 |
Author(s) |
Xu GH, Chague V, Melamed-Bessudo C, Kapulnik Y, Jain A, Raghothama KG, Levy AA, Silber A , 2007 |
Affiliation |
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China. email: E-mail: (Yoram Kapulnik)avnsil@volcani.agri.gov.il |
Title |
Functional characterization of LePT4: a phosphate transporter in tomato with mycorrhiza-enhanced expression |
Source. Vol.(no):Page |
JOURNAL OF EXPERIMENTAL BOTANY. 58(10):2491-2501p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry |
Sub-subjects |
Phosphorus metabolism |
Host |
Lycopersicon esculentum |
Organism |
AMF |
Country |
China, Asia |
Abstracts |
Many plant roots acquire inorganic phosphate (Pi) from soils directly through the root-soil interface via high-affinity Pi transporters and/or through symbiotic associations between the cortical cells and arbuscular mycorrhizal fungi. In tomato, three phosphate transporters (LePT3, LePT4, and LePT5) are up-regulated upon colonization by arbuscular mycorrhizal fungi. In this study, the role of LePT4 in tomato is elucidated by molecular and physiological characterizations of a loss-of-function mutant lept4. In the absence of mycorrhizal infection and under solution-Pi concentrations (Cp) of 0.05 mM and 0.5 mM, the mutant exhibited severe Pi-deficiency symptoms which were associated with significantly lower Pi uptake as compared with that of the wild type. However, at a Cp of 5 mM, lept4 grew better than the wild type. Mycorrhizal infection at a Cp of 0.05 mM resulted in a significant increase in the transcripts of LePT4 in the wild type and a concomitant 2-fold increase in Pi uptake. Although upon mycorrhizal infection, lept4 also exhibited an increased Pi uptake, it was significantly lower than that of the wild type. Under a Cp of 1 mM and in the absence of mycorrhizal infection, LePT4 expression was suppressed in the wild type and a mutation in this gene resulted in a slight reduction in total Pi uptake. These data highlight the pivotal role of LePT4 in mycorrhizal-mediated Pi uptake in tomato, and show that this function may not be fully compensated by other members of the family. Characterization of the mycorrhiza-associated Pi transporter lept4 mutant, along with expression analysis of LePT3, provides evidence for the different routes of mycorrhiza-mediated Pi uptake in plants |