Stress tolerance to stress escape in plants: role of the OXS2 zinc-finger transcription factor family

Abstract

During dire conditions, the channelling of resources into reproduction ensures species preservation. This strategy of survival through the next generation is particularly important for plants that are unable to escape their environment but can produce hardy seeds. Here, we describe the multiple roles of OXIDATIVE STRESS 2 (OXS2) in maintaining vegetative growth, activating stress tolerance, or entering into stress-induced reproduction. In the absence of stress, OXS2 is cytoplasmic and is needed for vegetative growth; in its absence, the plant flowers earlier.Upon stress, OXS2 is nuclear and is needed for stress tolerance; in its absence, the plant is stress sensitive. OXS2 can activate its own gene and those of floral integrator genes, with direct binding to the floral integrator promoter SOC1. Stress-induced SOC1 expression and stress-induced flowering are impaired in mutants with defects in OXS2 and three of the four OXS2-like paralogues. The autoactivation of OXS2 may be a commensurate response to the stress intensity, stepping up from a strategy based on tolerating the effects of stress to one of escaping the stress via reproduction.

Maize OXIDATIVE STRESS2 Homologs Enhance Cadmium Tolerance in Arabidopsis through Activation of a Putative SAM-Dependent Methyltransferase Gene

“…Approximately 10 independent transgenic lines were obtained for each transformation. Unlike overexpression of AtOXS2 that caused early flowering (Blanvillain et al, 2011), we did not observe early flowering with the four classes of transgenic lines: WT(ZmOXS2b), WT(ZmO2L1), oxs2-1(ZmOXS2b), and o2l1-1 (ZmO2L1). Three independent lines from each class were randomly selected and homozygous plants obtained for further analysis.…”

“…As AtOXS2 is known to activate promoters of some flowering genes (Blanvillain et al, 2011), it would seem plausible that ZmOXS2b and ZmO2L1 may recognize heterologous promoters from a similar protein-structure/DNA sequence interaction. To examine if the gene expression pattern has changed, an RNA-seq analysis was conducted on Cd-treated plants comparing WT(ZmOXS2b) and WT(ZmO2L1) against the wild-type control.…”

“…The Arabidopsis (Arabidopsis thaliana) zinc finger protein OXS2 (OXIDATIVE STRESS2) was previously found to induce stress escape through the direct activation of at least one floral integrator gene, SOC1, by binding the BOXS2 cis-element in its promoter (Blanvillain et al, 2011). Because a loss of function in AtOXS2 is more sensitive to stress, AtOXS2 was also proposed to play a role in alleviating stress tolerance.…”

The Myb-domain protein ULTRAPETALA1 INTERACTING FACTOR 1 controls floral meristem activities in Arabidopsis

“…Micro-projectiles were prepared with 50 ng of pRLC (Renilla luciferase construct), 400 ng of pBB168 (firefly luciferase construct; Blanvillain et al, 2011) and 15 µg of G4DBD-UIF1, G4DBD-UIF1-dCT or G4DBD-UIF1-ANANA-dCT. Onion epidermal cells were transfected as described above and kept in the dark for 20 h at 21°C, before being ground in liquid nitrogen.…”

Mitigation of Salt Stress-Induced Inhibition of Plantago crassifolia Reproductive Development by Supplemental Calcium or Magnesium

“…Stress can induce both, early or delayed flowering, depending on the particular plant species, but also on the type and the intensity of the stress conditions. These different outputs probably correspond to different strategies that can be used by plants to cope with stress: either they invest their resources (energy, nutrients, metabolic precursors) in defence reactions against stress, delaying reproductive development-which would also require those resources-or they escape stress using a strategy of 'survival through the next generation' , by induction of early flowering and reproduction to produce seeds (e.g., Blanvillain et al, 2011), as seems to be the case in our experiments. Nevertheless, since salt stress imposes additional energy requirements on plants, fewer resources are available for development of reproductive structures, male and female gametophytes and, after fertilisation, for embryo and seed development (Cheesman, 1988).…”