Comparative analysis of PvPAP gene family and their functions in response to phosphorus deficiency in common bean.
BACKGROUND
Purple acid phosphatases (PAPs) play a vital role in adaptive strategies of plants to phosphorus (P) deficiency. However, their functions in relation to P efficiency are fragmentary in common bean.


RESULTS
Five PvPAPs were isolated and sequenced in common bean. Phylogenetic analysis showed that PvPAPs could be classified into two groups, including a small group with low molecular mass, and a large group with high molecular mass. Among them, PvPAP3, PvPAP4 and PvPAP5 belong to the small group, while the other two belong to the large group. Transient expression of 35S:PvPAPs-GFP on onion epidermal cells verified the variations of subcellular localization among PvPAPs, suggesting functional diversities of PvPAPs in common bean. Quantitative PCR results showed that most PvPAPs were up-regulated by phosphate (Pi) starvation. Among them, the expression of the small group PvPAPs responded more to Pi starvation, especially in the roots of G19833, the P-efficient genotype. However, only overexpressing PvPAP1 and PvPAP3 could result in significantly increased utilization of extracellular dNTPs in the transgenic bean hairy roots. Furthermore, overexpressing PvPAP3 in Arabidopsis enhanced both plant growth and total P content when dNTPs were supplied as the sole external P source.


CONCLUSIONS
The results suggest that PvPAPs in bean varied in protein structure, response to P deficiency and subcellular localization. Among them, both PvPAP1 and PvPAP3 might function as utilization of extracellular dNTPs.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Root Biology Center, South China Agricultural University, Guangzhou, People's Republic of China.
Cuiyue
C
Liang
Lili
L
Sun
Zhufang
Z
Yao
Hong
H
Liao
Jiang
J
Tian
D000135:Acid Phosphatase / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D007887:Fabaceae / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006023:Glycoproteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D005810:Multigene Family; D019697:Onions / Q000166:cytology / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D010802:Phylogeny; D059828:Plant Cells / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport
D006023:Glycoproteins; D010758:Phosphorus; C091137:purple acid phosphatase; D000135:Acid Phosphatase