Light Moderates the Induction of Phosphoenolpyruvate Carboxylase by NaCl and Abscisic Acid in Mesembryanthemum crystallinum

Abstract

ABSTRACT

Photomorphogenesis and phyfohormones

“…The relationships between ABA and light in development are complex, since light and ABA act synergistically in some cases (McElwain et al 1992) and antagonistically in others (Chang & Walling 1991;Toyomasu et al 1994). The question of related or independent regulation by light and ABA has been addressed by several groups, who have established correlations between light treatment, ABA levels and biological responses of plants.…”

“…Depending on the species considered and the experitnental conditions, all kinds of interactions (additivity, synergism and antagonistn) have been observed. For exatnple, the expression of many plastidic genes is induced by both light and cytokinins (Bracale et al 1988;Cohen et al 1988); cell elongation is induced by auxin and gibberellins, but is inhibited by blue (B), red (R) and far-red (FR) light perceived by cryptochrotnes and phytochromes; ABA and light have synergistic effects on phosphoenol pyruvate carboxylase gene expression (McElwain et al 1992), but antagonistic effects on chlorophyll a,b binding protein gene transcription (Weatherwax etal 1996).…”

NPR Genes, Which Are Negatively Regulated by Phytochrome Action in Lemna gibba L. G-3, Can Also Be Positively Regulated by Abscisic Acid

“…ABA treatment has been found to repress the expression of genes encoding the small and large subunits of Rubisco (rbcS and rbcL genes) and Chl a/b-binding proteins (Lhc genes) (Quatrano et al, 1983;Medford and Sussex, 1989;Cherepneva and Kuznetsov, 1990;Bartholomew et al, 1991;Chang and Walling, 1991). Light has also been reported to act as a positive factor in the expression of two different ABA-induced genes (Bartels et al, 1992;McElwain et al, 1992). A short R irradiation has been reported to induce a decrease in ABA content in Scots pine seeds (Tillberg, 1992).…”

Characterization of a Salt-Responsive 24-Kilodalton Glycoprotein in Mesembryanthemum crystallinum

“…It is able to survive both drought and salt stress through unique stress-tolerance mechanisms. ABA also appears to have a role in regulating CAM induction, although its mechanism is not yet understood (Chu et al, 1990;McElwain et al, 1992).When M. crystallinum is exposed to high extemal salt, Pro (Heun et al, 1981) and pinitol (Paul and Cockbum, 1989) accumulate in the cytoplasm where they function as compatible solutes. Apparently this allows a physiological range of Na ions to be maintained in the cytosol while compartmentalizing excess NaCl in the vacuole or intercellular space.…”

“…It is able to survive both drought and salt stress through unique stress-tolerance mechanisms. ABA also appears to have a role in regulating CAM induction, although its mechanism is not yet understood (Chu et al, 1990;McElwain et al, 1992).…”