Abscisic acid is involved in several processes associated with root system architecture in maize

Abstract

Studies concerning abscisic acid (ABA) involvement in root system architecture (RSA) and the interaction of ABA with auxin have reported contrasting results. In this study, the effects of exogenous ABA application and withdrawal as well as a combined treatment of ABA with the synthetic auxin 1-naphthaleneacetic acid (NAA) were thoroughly investigated in maize. The results showed that ABA reduced both the primary root (PR) elongation and the lateral root density (LRD), whereas NAA inhibited PR elongation but increased LRD. The combined treatment involving ABA and NAA inhibited PR elongation. Regarding ABA withdrawal, PR elongation was restored when ABA was removed from the growth media, but LRD was not restored after ABA withdrawal. However, the results of the combined treatment showed that auxin can reverse the inhibitory effect of ABA on LRD. A more in-depth analysis revealed that the inhibitory effect of ABA on lateral root (LR) formation depends on the stage of development. Exogenously added ABA blocked the development of lateral root primordia (LRPs) in the early stages, but was unable to inhibit the elongation of developed LRPs. These results suggest that ABA arrests the formation of LRPs rather than the growth and emergence of LRPs and their subsequent elongation.

14-3-3 Proteins and the Plasma Membrane H+-ATPase Are Involved in Maize (Zea mays) Magnetic Induction

“…From a carbon and nitrogen metabolic point of view, sucrose loading is stimulated by IAA and inhibited by ABA, whereas sucrose uptake by sinks shows the opposite [54]. Our results suggest that NNMF, by altering the IAA and ABA levels, might influence the gene expression of sucrose synthase.…”

Differential roles of abscisic acid in maize roots in the adaptation to soil drought

“…ABA signal in roots is required for a series of processes including the maintenance of primary root elongation and the repression of lateral root formation under water‐deficit conditions (Deak & Malamy, 2005; Sharp et al, 2004). Recently, a new study also points out that ABA is involved in several processes associated with root system architecture in maize (Friero et al, 2022). However, studies have shown that ABA acts in the regulation of roots with a dose effect.…”

“…However, high concentrations of ABA not only inhibits cell division in the apical meristems but also represses cell expansion in the elongation zone in roots (Bai et al, 2009; Yang et al, 2014). Additionally, key cellular components auxin, ethylene, reactive oxygen species (ROS), and Ca 2+ are found involved in the regulation of ABA suppression of root elongation (Bai et al, 2009; Friero et al, 2022; Sun et al, 2018; Thole et al, 2014). These elucidate the key mechanisms underlying the differential roles of ABA in the adaptation to soil drought.…”