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

CAMPESTRE M.P.; ANTONELLI C.J.; CALZADILLA P.I.; MAIALE S.; RODRÍGUEZ A.; RUIZ O.A.

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 was investigated underalkaline conditions. Sensitive, but not tolerant ecotypes, showed interveinal chlorosis under all alkalinityconditions and high mortality under extreme alkalinity. Interveinal chlorosis was associated with Fedeficiency, as a reduced Fe2+shoot content was observed in all sensitive ecotypes. In addition, someshowed a decline in photosynthesis rate and PSII performance compared to the control. In contrast,some tolerant ecotypes did not change these parameters between treatments. Alkaline tolerance couldbe explained by a mechanism of Fe acquisition and a root structural modification. This conclusion wasbased on the fact that all tolerant, but not the sensitive ecotypes, presented high ferric reductase oxidaseactivity under alkaline stress compared to the control, and a Herringbone root pattern modification. Onthis basis, the analysis of these mechanisms of alkaline tolerance could be used in screening programsfor the selection of new tolerant genotypes in the Lotus genus.