OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 151/1/233    most recent pp.109.138891v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Google Scholar Articles by Wang, X. Articles by Liao, H. PubMed PubMed Citation Articles by Wang, X. Articles by Liao, H. Pubmed/NCBI databases Gene GEO Profiles HomoloGene UniGene Agricola Articles by Wang, X. Articles by Liao, H.

ENVIRONMENTAL STRESS AND ADAPTATION TO STRESS

Overexpressing AtPAP15 Enhances Phosphorus Efficiency in Soybean^1,[W],[OA]

Root Biology Center, South China Agricultural University, Guangzhou 510642, China (X.W., Y.W., J.T., X.Y., H.L.); and School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong, China (B.L.L.)

Low phosphorus (P) availability is a major constraint to crop growth and production, including soybean (Glycine max), on a global scale. However, 50% to 80% of the total P in agricultural soils exists as organic phosphate, which is unavailable to plants unless hydrolyzed to release inorganic phosphate. One strategy for improving crop P nutrition is the enhanced activity of acid phosphatases (APases) to obtain or remobilize inorganic phosphate from organic P sources. In this study, we overexpressed an Arabidopsis (Arabidopsis thaliana) purple APase gene (AtPAP15) containing a carrot (Daucus carota) extracellular targeting peptide in soybean hairy roots and found that the APase activity was increased by 1.5-fold in transgenic hairy roots. We subsequently transformed soybean plants with AtPAP15 and studied three homozygous overexpression lines of AtPAP15. The three transgenic lines exhibited significantly improved P efficiency with 117.8%, 56.5%, and 57.8% increases in plant dry weight, and 90.1%, 18.2%, and 62.6% increases in plant P content, respectively, as compared with wild-type plants grown on sand culture containing phytate as the sole P source. The transgenic soybean lines also exhibited a significant level of APase and phytase activity in leaves and root exudates, respectively. Furthermore, the transgenic lines exhibited improved yields when grown on acid soils, with 35.9%, 41.0%, and 59.0% increases in pod number per plant, and 46.0%, 48.3%, and 66.7% increases in seed number per plant. Taken together, to our knowledge, our study is the first report on the improvement of P efficiency in soybean through constitutive expression of a plant APase gene. These findings could have significant implications for improving crop yield on soils low in available P, which is a serious agricultural limitation worldwide.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Hong Liao (hliao{at}scau.edu.cn).

^[W] The online version of this article contains Web-only data.

^[OA] Open access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.109.138891

^* Corresponding author; e-mail hliao{at}scau.edu.cn.

Received March 21, 2009; accepted June 29, 2009; published July 8, 2009.