The alkaline tolerance in Lotus japonicus is associated with mechanisms of iron acquisition and modification of the architectural pattern of the root

MARIA PAULA CAMPESTRE; CRISTIAN ANTONELLI; PABLO CALZADILLA; SANTIAGO JAVIER MAIALE; ANDRES ALBERTO RODRIGUEZ (CORRESPONDING AUTHOR); OSCAR ADOLFO RUIZ

JOURNAL OF PLANT PHYSIOLOGY

ELSEVIER GMBH

Año: 2016 vol. 206 p. 40 - 48

0176-1617

The response of fifty-four Lotus japonicus ecotypes, and of six selected ecotypes wasinvestigated under alkaline conditions. Sensitive, but not tolerant ecotypes, showed interveinal chlorosis under all alkalinity conditions and highmortality under extreme alkalinity. Interveinal chlorosis was associatedwith Fe deficiency, as a reduced Fe2+ shootcontent was observed in all sensitive ecotypes. In addition, some showed adecline in photosynthesis rate and PSII performance compared to the control. Incontrast, some tolerant ecotypes did not change these parameters betweentreatments. Alkaline tolerance could be explained by a mechanism of Fe acquisition and a root structural modification. Thisconclusion was based on the fact that alltolerant, but not the sensitive ecotypes, presented high ferric reductase oxidase activity under alkaline stress compared to the control, and a Herringboneroot pattern modification. Onthis basis, the analysis of these mechanisms of alkaline tolerance could beused in screening programs for the selection of new tolerant genotypes in the Lotus genus.