Barley plants carrying the altered function Sln1d allele display modified responses to low phosphorus supply: implications for phosphorus utilisation efficiency

GUALANO, LEONARDO; MORICONI, JORGE I.; OLIFERUK, SONIA; SILVA, MARTHA; TRANQUILLI, GABRIELA E.; SANTA-MARÍA, GUILLERMO E.

FUNCTIONAL PLANT BIOLOGY

CSIRO PUBLISHING

Año: 2021

1445-4408

The moduleGA-GID1-DELLA (Gibberellin-Gibberellin Receptor-DELLA proteins) provides apoint for theintegration of signals potentially relevant in determining nutrient utilisationand acquisition efficiencies. In this study, we explored the role of components ofthis module during the acclimation of barley plants (Hordeum vulgareL.) to different phosphorus(P) supplies by using two related genotypes, harbouring either the WT or the Sln1d alleles of the DELLA-coding geneSln1. Dwarf Sln1d plants exhibited reducedshoot P utilisation efficiency (PUtE) and better performance at low levels of P supply.The superior PUtE displayed by WT plants disappeared when corrected by internalP concentration, indicating that multiple analyses are necessary to fullyunderstand the meaning of PUtE estimates. Over a wide range of external suppliesof P, Sln1d plants displayed enhanced Pconcentration, which was associated with low relative growth rate, high biomasspartitioning to roots and high P-uptake-rate, thus suggesting that the effectof the Sln1d allele on P dynamics is not simplya consequence of slow growth habit. An enhanced P concentration was also foundin a mutant with defectiveGAssynthesis.OurresultssuggestthatcomponentsoftheGA-GID1-DELLAs module contributeto set the acclimation response of barley plants to low P supply through bothP-dynamics dependent and P-dynamics independent mechanisms.