An isopentenyl transferase transgenic wheat isoline exhibits less seminal root growth impairment and a differential metabolite profile under Cd stress

GOMEZ MANSUR, NABILA M.; PENA, LILIANA B.; BOSSIO, ADRIÁN E.; LEWI, DALIA M.; BEZNEC, AILIN Y.; BLUMWALD, EDUARDO; ARBONA, VICENT; GÓMEZ?CADENAS, AURELIO; BENAVIDES, MARÍA P.; GALLEGO, SUSANA M.

PHYSIOLOGIA PLANTARUM

WILEY-BLACKWELL PUBLISHING, INC

Año: 2021

0031-9317

Cadmium is one of the most important contaminants and it induces severe plantgrowth restriction. In this study, we analyzed the metabolic changes associated withroot growth restriction caused by cadmium in the early seminal root apex of wheat.Our study included two genotypes: the commercial variety ProINTA Federal(WT) and the PSARK::IPT (IPT) line which exhibit high-grade yield performance underwater deficit. Root tips of seedlings grown for 72 h without or with 10 μM CdCl2(Cd-WT and Cd-IPT) were compared. Root length reduction was more severe in Cd-WT than Cd-IPT. Cd decreased superoxide dismutase activity in both lines andincreased catalase activity only in the WT. In Cd-IPT, ascorbate and guaiacol peroxidaseactivities raised compared to Cd-WT. The hormonal homeostasis was alteredby the metal, with significant decreases in abscisic acid, jasmonic acid,12-oxophytodienoic acid, gibberellins GA20, and GA7 levels. Increases in flavonoidsand phenylamides were also found. Root growth impairment was not associated witha decrease in expansin (EXP) transcripts. On the contrary, TaEXPB8 expressionincreased in the WT treated by Cd. Our findings suggest that the line expressing thePSARK::IPT construction increased the homeostatic range to cope with Cd stress,which is visible by a lesser reduction of the root elongation compared to WT plants.The decline of root growth produced by Cd was associated with hormonal imbalanceat the root apex level. We hypothesize that activation of phenolic secondary metabolismcould enhance antioxidant defenses and contribute to cell wall reinforcement todeal with Cd toxicity.