Senescence-inducible cell wall and intracellular purple acid phosphatases: implications for phosphorus remobilization in Hakea prostrata (Proteaceae) and Arabidopsis thaliana (Brassicaceae)

Abstract

SummaryTargeting of senescence-inducible acid phosphatases and RNases to the cell wall and vacuolar compartments appears to make a crucial contribution to efficient P remobilization networks of senescing tissues of Hakea prostrata and Arabidopsis.

Molecular mechanisms underpinning phosphorus‐use efficiency in rice

“…Hence, these two enzymes act on two of the RNA‐protecting mechanisms, respectively, capping and polyadenylation (Jeong et al, ). Excellent P remobilization, paralleled by highly up‐regulated activities of intracellular and cell wall localized RNase and PAP during leaf senescence of harsh hakea and Arabidopsis (Shane et al, ), also highlights the importance of RNA as a source of P for remobilization at the later stage of plant growth.…”

“…OsPAP26 is expressed at a higher level in senescing leaves, and Pi distribution in both senescing and non‐senescing leaves is affected when OsPAP26 expression is altered by genetic engineering, highlighting the important role of OsPAP26 in P remobilization from senescing leaves to young leaves (Gao et al, ). OsPAP26 is an ortholog of AtPAP26, which has been characterized as the principle contributor to intracellular and extracellular APase activity and Pi scavenging during Arabidopsis Pi deprivation or leaf senescence (Hurley et al, ; Robinson, Carson, et al, ; Robinson, Park, et al, ; Shane et al, ; Stigter & Plaxton, ). AtPAP26's functions likely include scavenging Pi from 3'NMPs derived from nuclease‐mediated nucleic acid hydrolysis.…”

The Binding Mode of an ADP Analogue to a Metallohydrolase Mimics the Likely Transition State

“…[1][2][3][4] Examples include the antibiotic-degrading metallo-b-lactamases, pesticide-decontaminating organophosphate hydrolases, and purple acid phosphatases (PAPs). [13,14] Due to their diverse roles, PAPs have attracted attention either as targetsf or new treatments of osteoporosis or for applicationsi na griculture to aid nutrient uptake by crops. [2,5] Mostp lant PAPs use either Zn II or Mn II ,w hereas their mammalianc ounterparts employ ar edox-activei ron ( Figure 1).…”

“…[2,5] The biological functions of PAPs are diverse and dependent on the organism. [13,14] Due to their diverse roles, PAPs have attracted attention either as targetsf or new treatments of osteoporosis or for applicationsi na griculture to aid nutrient uptake by crops. [11,12] In plants, PAPs playamajor role in the acquisition of phosphorus, especially if there is al imited supplyo fp hosphate.…”

Lectin AtGAL1 interacts with high‐mannose glycoform of the purple acid phosphatase AtPAP26 secreted by phosphate‐starved Arabidopsis

“…In contrast to the abundance of plant PAP genomic and transcriptomic data, comparatively little information is available on the identity and detailed biochemical characteristics of specific PAP isozymes that mediate intracellular versus extracellular Pi scavenging and remobilization. However, integrated biochemical and functional genomic studies have established the Arabidopsis PAP AtPAP26 (and its orthologue from rice, common bean, and stylo): (a) as a principal contributor to intracellular and extracellular PSI APase activity and (b) to play a central role in Pi‐scavenging and recycling during Pi deprivation or leaf senescence (Gao, Lu, Qiu, Wang, & Shou, ; Hurley et al, ; Liang, Sun, Yao, Liao, & Tian, ; Liu, Xue, Chen, Liu, & Tian, ; Robinson, Carson, Ying, Ellis, & Plaxton, ; Robinson, Park, et al, ; Shane, Stigter, Fedosejevs, & Plaxton, ; Tran et al, ; Veljanovski, Vanderbeld, Knowles, Snedden, & Plaxton, ; Wang & Liu, ; Wang et al, ). Native enzyme purification and characterization led to the discovery that AtPAP26 is secreted as a pair of distinct glycoforms (AtPAP26‐S1 and AtPAP26‐S2) by −Pi Arabidopsis (Del Vecchio et al, ; Ghahremani et al, ; Tran, Qian, et al, ).…”