A GlutathioneS-Transferase Regulated by Light and Hormones Participates in the Modulation of Arabidopsis Seedling Development

Abstract

Glutathione S-transferases (GSTs) have been well documented to be involved in diverse aspects of biotic and abiotic stresses, especially detoxification processes. Whether they regulate plant development remains unclear. Here, we report on our isolation by reverse transcription-polymerase chain reaction of a plant GST, AtGSTU17, from Arabidopsis (Arabidopsis thaliana) and demonstrate that its expression is regulated by multiple photoreceptors, especially phytochrome A (phyA) under all light conditions. Further physiological studies indicated that AtGSTU17 participates in various aspects of seedling development, including hypocotyl elongation, anthocyanin accumulation, and far-red light-mediated inhibition of greening with a requirement of functional phyA. The loss-of-function mutant of AtGSTU17 (atgstu17) resulted in reduced biomass of seedlings and number of lateral roots in the presence of auxin, as well as insensitivity to abscisic acid (ABA)-mediated inhibition of root elongation, with similarity to different phyA mutant alleles. Moreover, the root phenotype conferred by atgstu17 was reflected by histochemical b-glucuronidase staining of AtGSTU17 promoter activity with the addition of auxin or ABA. Further microarray analysis of wild-type Columbia and atgstu17 seedlings treated with far-red irradiation or ABA revealed that AtGSTU17 might modulate hypocotyl elongation by positively regulating some light-signaling components and negatively regulating a group of auxin-responsive genes and modulate root development by negatively controlling an auxin transport protein in the presence of ABA. Therefore, our data reveal that AtGSTU17 participates in light signaling and might modulate various aspects of Arabidopsis development by affecting glutathione pools via a coordinated regulation with phyA and phytohormones.

N-acetylcysteine and Zn regulate corn yield

“…3). Glutathione modulates development of Arabidopsis plants 24 which is similar to the results by Jahan et al 11 who showed that a deficient GSH content controls leaf development as well as plant growth of ch1-1 mutant Arabidopsis plants. These results agree with our study.…”

Glutathione in plants: biosynthesis and physiological role in environmental stress tolerance

“…GSH and glutaredoxins are concerned with detoxification of ROS, but they also transmit redox signals under drought stress (Meyer 2008). The GSH pools in the Arabidopsis atgstu17 mutant were 35% higher compared with wild-type plants (Jiang et al 2010). Application of exogenous betaine and proline application improved GSH level and maintained high activities of GST and Gly I, thereby protecting lentil plants from oxidative damage and toxic effects of MG (Molla et al 2014).…”

Arabidopsis Phytochrome A Directly Targets Numerous Promoters for Individualized Modulation of Genes in a Wide Range of Pathways

“…Interestingly, the association of phyA with the NAC019 promoter mediates the transcriptional regulation of NAC019 in response to both FR and ABA (Figures 6 and 8). As NAC019 is a transcription factor, it is conceivable that At GSTU17, a GST that participates in ABA-mediated inhibition of root elongation under white light (Jiang et al, 2010), is subsequently regulated by NAC019 under FR. It is likely that more ABA-responsive intermediates in addition to NAC019 are also involved in FR-modulated root elongation, since NAC019 has multiple functionally redundant homologs, such as NAC072 and NAC055 (Tran et al, 2004).…”

“…Moreover, abscisic acid (ABA) signaling interferes with phyA-dependent seed germination (Lee et al, 2012). On the other hand, phyA synergistically coordinates with ABA to inhibit root elongation under white light (Jiang et al, 2010). Yet, the mechanism by which phyA influences the expression of ABA-responsive genes and collaborates with ABA responses under FR awaits further investigation.…”