The secreted purple acid phosphatase isozymes AtPAP12 and AtPAP26 play a pivotal role in extracellular phosphate-scavenging by Arabidopsis thaliana.
The secreted purple acid phosphatase isozymes AtPAP12 and AtPAP26 play a pivotal role in extracellular phosphate-scavenging by Arabidopsis thaliana.
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DOI：
10.1093/jxb/ers309
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发表时间：
2012-11
影响因子：
6.9
通讯作者：
Plaxton WC
中科院分区：
文献类型：
--
作者：
Robinson WD;Park J;Tran HT;Del Vecchio HA;Ying S;Zins JL;Patel K;McKnight TD;Plaxton WC
正磷酸盐（Pi）是植物生长所必需的但限制性的大量营养素。土壤磷以有机磷的形式存在，只有被分泌型酸性磷酸酶水解后才能被根系吸收。缺磷拟南芥（Arabidopsis thaliana）根分泌的主要紫色AP酶（PAP）同工酶为AtPAP 12（At 2g 27190）和AtPAP 26（At 5g 34850）。目前的研究表明，外源Po化合物，如甘油-3-磷酸或鲱鱼精DNA：（i）有效地取代Pi支持拟南芥幼苗的磷营养，（ii）引起AtPAP 12和AtPAP 26的上调和分泌到生长培养基中。当在低磷条件下培养或以Po作为唯一磷源时，atpap 26/atpap 12 T-DNA双插入突变体表现出生长受损，根系分泌APase活性和莲座丛总磷浓度分别下降> 60%和>30%。atpap 12/atpap 26突变体的发展是不受影响的生长过程中的Pi-充满培养基，但完全被逮捕时，7天大的Pi-足够的幼苗移植到一个-Pi，PO-含有土壤混合物。这两个PAP也强烈上调根表面和芽细胞壁提取物的-Pi幼苗。据推测，分泌的AtPAP 12和AtPAP 26通过以下方式促进拟南芥对营养性Pi缺乏的适应：（i）在根际中起作用以从土壤的可接近的Po池中吸收Pi，同时（ii）从已经从细胞质泄漏到细胞壁中的内源性磷酸单酯中回收Pi。因此，AtPAP 12和AtPAP 26是提高作物磷利用效率的有希望的靶标。
Orthophosphate (Pi) is an essential but limiting macronutrient for plant growth. Extensive soil P reserves exist in the form of organic P (Po), which is unavailable for root uptake until hydrolysed by secretory acid phosphatases (APases). The predominant purple APase (PAP) isozymes secreted by roots of Pi-deficient (–Pi) Arabidopsis thaliana were recently identified as AtPAP12 (At2g27190) and AtPAP26 (At5g34850). The present study demonstrated that exogenous Po compounds such as glycerol-3-phosphate or herring sperm DNA: (i) effectively substituted for Pi 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 –Pi conditions or supplied with Po 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 Pi concentration, respectively. Development of the atpap12/atpap26 mutant was unaffected during growth on Pi-replete medium but was completely arrested when 7-day-old Pi-sufficient seedlings were transplanted into a –Pi, Po-containing soil mix. Both PAPs were also strongly upregulated on root surfaces and in shoot cell-wall extracts of –Pi seedlings. It is hypothesized that secreted AtPAP12 and AtPAP26 facilitate the acclimation of Arabidopsis to nutritional Pi deficiency by: (i) functioning in the rhizosphere to scavenge Pi from the soil’s accessible Po pool, while (ii) recycling Pi from endogenous phosphomonoesters that have been leaked into cell walls from the cytoplasm. Thus, AtPAP12 and AtPAP26 are promising targets for improving crop P-use efficiency.
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影响因子：
7.4
作者：
Liang, Cuiyue;Tian, Jiang;Liao, Hong
通讯作者：
Liao, Hong
影响因子：
6.9
作者：
BARRETTLENNARD, EG;DRACUP, M;GREENWAY, H
通讯作者：
GREENWAY, H
影响因子：
7.4
作者：
LEFEBVRE, DD;DUFF, SMG;PLAXTON, WC
通讯作者：
PLAXTON, WC
影响因子：
7.2
作者：
Clough, SJ;Bent, AF
通讯作者：
Bent, AF
影响因子：
7.2
作者：
del Pozo, JC;Allona, I;Paz-Ares, J
通讯作者：
Paz-Ares, J