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United States Department of Agriculture

Agricultural Research Service

Research Project: MANAGEMENT STRATEGIES FOR MEETING AGRONOMIC, ENVIRONMENTAL, AND SOCIETAL CROP PRODUCTION DEMANDS

Location: Agroecosystem Management Research

Title: Arbuscular mycorrhizal fungi differ in their ability to regulate the expression of phosphate transportors in maize (Zea mays L.))

Author
item Tian, Hui
item Drijber, Rhae
item Li, Xiaolin
item Miller, Daniel
item Wienhold, Brian

Submitted to: Mycorrhiza
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/18/2013
Publication Date: 3/7/2013
Publication URL: http://handle.nal.usda.gov/10113/57994
Citation: Tian, H., Drijber, R.A., Li, X., Miller, D.N., Wienhold, B.J. 2013. Arbuscular mycorrhizal fungi differ in their ability to regulate the expression of phosphate transportors in maize (Zea mays L.). Mycorrhiza. Available: http://link.springer.com/article/10.1007/s00572-013-0491-1/fulltext.html.

Interpretive Summary: Molecular methods were used to identify mycorrhizal species infecting maize grown in rotation with soybean. Long-term N fertilization did not reduce the incidence of mycorrhizal infection. A greenhouse experiment was conducted to study the expression of an epidermal-expressed phosphorus transporter gene and an arbuscular mycorrhizal specific induced phosphorus transporter gene in maize either colonized or not colonized by mycorrhiza. Expression of the mycorrhizal specific P transporter gene activity was positively correlated with mycorrhizal biomass on maize roots, plant P uptake and shoot weight but negatively correlated with epidermal-expressed P transporter gene activity.

Technical Abstract: A greenhouse experiment was conducted to study the expression of two phosphate (P) transporter genes ZEAma:Pht1;3 (epidermal-expressed) and ZEAma:Pht1;6 (AM specific induced, and expressed around arbuscules) in maize root to colonization by different arbuscular mycorrhizal (AM) fungal inoculants. Non-mycorrhizal maize, maize colonized by Glomus deserticola (CA113), Glomus intraradices (IA506), Glomus mosseae (CA201), Gigaspora gigantean (MN922A) and the co-inoculation of all four species were established. Plant materials were harvest after nine weeks, and root length colonized by AM fungi, AM fatty acid biomarkers, biomass of shoots and P uptake in shoot were measured. The expression patterns of the two genes were quantified using Real-time RT-PCR. Different AM inoculations showed distinct functional diversity in P uptake or growth. The expression level of ZEAma:Pht1;6 was 26-135 times higher in AM plants than in non-mycorrhizal maize roots; whereas the expression level of ZEAma:Pht1;3 was 5-44 times lower in AM plants than in non-mycorrhizal plants. Expression of the two genes differed with inoculation treatment and increasing the diversity of AM fungi in maize roots led to greater expression of ZEAma:Pht1;6 as well as P uptake in shoots. The expression of ZEAma:Pht1;6 was significantly positively correlated with AM biomass in maize roots, P uptake and dry weight of shoot, but negatively correlated with the expression of ZEAma:Pht1;3. Addition of P fertilizer at low concentration significantly increased the expression of ZEAma:Pht1;6, but had no effect on the expression of ZEAma:Pht1;3.

Last Modified: 8/24/2016
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