The Phosphate Knowledge Center
|Title:||The secreted purple acid phosphatase isozymes AtPAP12 and AtPAP26 play a pivotal role in extracellular phosphate-scavenging by Arabidopsis thaliana|
|Author:||Robinson WD, Park J, Tran HT, Del Vecchio HA, Ying S, Zins JL, Patel K, McKnight TD, Plaxton WC|
|URL:||J Exp Bot|
Orthophosphate (P(i)) is an essential but limiting macronutrient for plant growth. Extensive soil P reserves exist in the form of organic P (P(o)), which is unavailable for root uptake until hydrolysed by secretory acid phosphatases (APases). The predominant purple APase (PAP) isozymes secreted by roots of P(i)-deficient (-P(i)) Arabidopsis thaliana were recently identified as AtPAP12 (At2g27190) and AtPAP26 (At5g34850). The present study demonstrated that exogenous P(o) compounds such as glycerol-3-phosphate or herring sperm DNA: (i) effectively substituted for P(i) in supporting the P nutrition of Arabidopsis seedlings, and (ii) caused upregulation and secretion of AtPAP12 and AtPAP26 into the growth medium. When cultivated under -P(i) conditions or supplied with P(o) as its sole source of P nutrition, an atpap26/atpap12 T-DNA double insertion mutant exhibited impaired growth coupled with >60 and >30% decreases in root secretory APase activity and rosette total P(i) concentration, respectively. Development of the atpap12/atpap26 mutant was unaffected during growth on P(i)-replete medium but was completely arrested when 7-day-old P(i)-sufficient seedlings were transplanted into a -P(i), P(o)-containing soil mix. Both PAPs were also strongly upregulated on root surfaces and in shoot cell-wall extracts of -P(i) seedlings.
|Submited to Green Pi:||2013-03-05 By farzi|
|Modified on Green Pi:||2013-03-19 By farzi|