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A defective ABC transporter of the MRP family, responsible for the bean lpa1 mutation, affects the regulation of the phytic acid pathway, reduces seed myo ‐inositol and alters ABA sensitivity
Author(s) -
Panzeri Dario,
Cassani Elena,
Doria Enrico,
Tagliabue Giovanni,
Forti Luca,
Campion Bruno,
Bollini Roberto,
Brearley Charles A.,
Pilu Roberto,
Nielsen Erik,
Sparvoli Francesca
Publication year - 2011
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2011.03666.x
Subject(s) - phytic acid , mutant , biology , genetics , mutation , gene , inositol , population , phenotype , biochemistry , receptor , demography , sociology
Summary• We previously identified the lpa1 (low phytic acid) 280‐10 line that carries a mutation conferring a 90% reduction in phytic acid (InsP 6 ) content. In contrast to other lpa mutants, lpa1 (280‐10) does not display negative pleiotropic effects. In the present paper, we have identified the mutated gene and analysed its impact on the phytic acid pathway. • Here, we mapped the lpa1 (280‐10) mutation by bulk analysis on a segregating F 2 population, an then, by comparison with the soybean genome, we identified and sequenced a candidate gene. The InsP 6 pathway was analysed by gene expression and quantification of metabolites. • The mutated Pvmrp1 (280‐10) cosegregates with the lpa1 (280‐10) mutation, and the expression level of several genes of the InsP 6 pathway are reduced in the lpa1 (280‐10) mutant as well as the inositol and raffinosaccharide content. PvMrp2 , a very similar paralogue of PvMrp1 was also mapped and sequenced. • The lpa1 mutation in beans is likely the result of a defective Mrp1 gene (orthologous to the lpa genes AtMRP5 and ZmMRP4 ), while its Mrp2 paralog is not able to complement the mutant phenotype in the seed. This mutation appears to down‐regulate the InsP 6 pathway at the transcriptional level, as well as altering inositol‐related metabolism and affecting ABA sensitivity.