ABSCISIC ACID INSENSITIVE 5 mediates light–ABA/gibberellin crosstalk networks during seed germination

Abstract

Appropriate timing of seed germination is crucial for plant survival and has important implications for agricultural production. Timely germination relies on harmonious interactions between endogenous developmental signals, especially abscisic acid (ABA) and gibberellins (GAs), and environmental cues such as light. Recently, a series of investigations with regard to the crosstalk between phytochromes, ABA, and GAs in the regulation of seed germination demonstrated that the transcription factor ABSCISIC ACID INSENSITIVE 5 (ABI5) is a central mediator in the light–ABA/GA cascades. Here, we review the information on ABI5 as a key player in light-, ABA-, and GA-signaling pathways to precisely control seed germination. We highlight the recent advances in ABI5-related studies, focusing on the regulation of seed germination, which is strictly controlled at both transcriptional and protein levels by numerous light-regulated factors. We further discuss the components of ABA- and GA-signaling pathways that could regulate ABI5 during seed germination, including transcription factors, E3 ligases, protein kinases, and phosphatases. The precise molecular mechanisms by which ABI5 mediates ABA–GA antagonistic crosstalk during seed germination are also described. Finally, some potential research hotspots underlying ABI5-mediated seed germination regulatory networks are proposed.

Identification and Characterization of the AREB/ABF Gene Family in Three Orchid Species and Functional Analysis of DcaABI5 in Arabidopsis

“…ABI5 as a typical bZIP protein is well known in response to ABA signaling [ 36 ]. The different expression profiles in DcaABI5 compared with ABI5 from Arabidopsis inspired us to investigate the role of ABI5 in D. catenatum .…”

“…For instance, plants overexpressing AREB2/ABF4 or ABF3 show increased sensitivity to ABA, whereas reduced expression of ABA/stress-regulated genes exhibited enhanced drought tolerance [ 33 ]. ABI5 is well known as the core transcriptional factor in the ABA signaling pathway, which could contribute to various types of stress tolerance, including drought, salt, cold, and heat [ 35 , 36 ].…”

The Soybean Expression Atlas v2: A comprehensive database of over 5000 RNA‐seq samples

“…The functions of part‐specific genes reflect well‐known processes and pathways that are key to the physiology of each body part, such as fatty acid accumulation and response to maturation‐ and germination‐related phytohormones in seeds (abscisic acid and gibberellin, respectively) (Chauffour et al., 2019; Li et al., 2022; Ogawa et al., 2003), defense‐related genes in seed coats (Nunes et al., 2021; Shalovylo et al., 2021; Silva et al., 2018), nodulation‐related transporters and signaling components in root nodules (Banasiak et al., 2021; Niño‐González et al., 2019; Zeng et al., 2023), and photosynthesis‐ and plant growth‐related gene families in aerial parts (Jeena et al., 2019; Ren and Gray, 2015; Stortenbeker and Bemer, 2019). Collectively, our results validate the data reliability in the Soybean Expression Atlas v2.…”

Genome-Wide Identification and Expression Analysis of bZIP Family Genes in Stevia rebaudiana

“…ABA is involved in suppressing GA biosynthesis. ABI5 regulates the expression of genes associated with ABA and GA metabolism and signaling to control ABA and GA levels [72]. SGs are diterpene secondary metabolites and share their biosynthesis pathway with GAs [73].…”