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United States Department of Agriculture

Agricultural Research Service

Title: A NOVEL ACID PHOSPHATASE IS INDUCED IN WHITE LUPIN ROOTS UNDER CONDITIONS OF PHOSPHORUS DEFICIENCY)

Author
item Fedorova, Maria
item Temple, Stephen
item Gilbert, Glena
item Allen, Deborah
item Vance, Carroll

Submitted to: American Society of Plant Physiologists Meeting
Publication Type: Abstract only
Publication Acceptance Date: 7/29/1999
Publication Date: N/A
Citation:

Interpretive Summary:

Technical Abstract: When grown under phosphorus deficient conditions (-P), white lupin (Lupinus albus L.) forms an increased number of short, densely clustered, lateral roots. These cluster or proteoid roots have higher rates of non- photosynthetic carbon fixation and altered metabolism that supports increased levels of organic acid exudation. This adaptation serves to enhance P solubilization and increases P availability to the plant. Recen findings indicate that proteoid roots possess an additional adaptation for increasing P availability. Roots from -P plants have significantly higher acid phosphatase (APase) activity in both intracellular samples and in root exudates. Native-PAGE revealed that under P-deficient conditions, a unique isoform of APase was induced between 10 and 12 days after emergence (DAE). This unique -P induced APase is exuded into the rhizosphere of proteoid root zones. Although this form was found in normal roots, it comprised the emajor form in proteoid roots of -P plants. A PCR product was generated using primers against conserved regions of other excreted and purple acid phosphatases. RNA blot analysis indicates that expression was observed in -P normal roots and was dramatically induced in -P proteoid roots at 14 DAE. No APase transcript was observed in +P normal or +P proteoid roots. Among various other nutritional stress treatments tested, only the presence of aluminum caused a significant induction of APase gene expression in proteoid roots. This research was supported by USDA-NRI grant number 98- 35100-6098.

Last Modified: 8/24/2016
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