ROS and ABA Signaling Are Involved in the Growth Stimulation Induced by Low-Dose Gamma Irradiation in Arabidopsis Seedling

Abstract

It has been well established that gamma rays at low doses have stimulatory effects on plant growth and development. However, our knowledge regarding the molecular mechanism underlying the growth stimulation remains limited. In this study, we report the role of reactive oxygen species (ROS) and abscisic acid (ABA) in the growth stimulation using irradiated Arabidopsis seeds. The results indicated that 50 Gy gamma irradiation presented maximal beneficial effects on germination index, root length, and fresh weight. The contents of hydrogen peroxide (H2O2) and activities of antioxidant enzymes under gamma irradiation were markedly higher than those of controls. ROS scavenging significantly suppressed the growth of the irradiated plants. Furthermore, endogenous ABA was induced under low-dose gamma irradiation. The growth stimulation and elevated H2O2 level were affected in the irradiated ABA-deficient mutant aba2-1 compared with the mutant control. Transcriptional expression analysis of selected genes revealed that several genes for ABA biosynthesis were upregulated, and the genes for ABA catabolic pathway and transport were differentially regulated in response to low-dose gamma irradiation. Our results suggest that ROS and ABA signaling play an essential role in the stimulatory effects of low-dose gamma irradiation and that ROS, as secondary molecules, mediate ABA signal transduction under irradiation in response to stress factors during plant growth.

Early response of barley embryos to low‐ and high‐dose gamma irradiation of seeds triggers changes in the transcriptional profile and an increase in hydrogen peroxide content in seedlings

“…ROS also can be actively produced by plant cells, acting as a common signal during plant responses to different stresses, thus representing a point of convergence during stress responses (Sewelam, Kazan, & Schenk, ). For instance, ROS mediated ABA signalling transduction after growth‐promoting low‐dose irradiation of A. thaliana (Qi et al, ). Apparently, acute stress exposure is capable to change the redox status of plant cell and to preserve high levels of ROS for sufficient amount of time after exposure termination (Table ).…”

The Synergistic Priming Effect of Exogenous Salicylic Acid and H2O2 on Chilling Tolerance Enhancement during Maize (Zea mays L.) Seed Germination

“…However, the over-accumulation of H 2 O 2 easily caused cell injury (Mittler et al, 2004; Bailly et al, 2008; Kumar et al, 2015). H 2 O 2 signal directly or indirectly involved in many signaling pathways of SA, GA, ABA, and so on (Durner and Klessig, 1999; Diaz-Vivancos et al, 2013; Maarouf et al, 2015; Qi et al, 2015). Antioxidant enzymes produced in plants such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) contributed to the endogenous H 2 O 2 balance (Noctor and Foyer, 1998; Slesak et al, 2007).…”

Effect of gamma irradiation on the 2-acetyl-1-pyrroline content during growth of Thai black glutinous rice (Upland rice)

“…The study of gamma irradiation effect have been previously reported on plants and rice such as seed germination, some plant chemical compounds and phytohormone compound (Kumar et al, 2013;Chen et al, 2015;Qi et al, 2015). Here, the 2AP content was investigated when rice was subjected to gamma ray.…”