Osmoregulation of a Pyrroline-5-Carboxylate Reductase Gene in Arabidopsis thaliana

Isolation, characterization, and chromosomal location of a gene encoding the Δ1‐pyrroline‐5‐carboxylate synthetase in Arabidopsis thaliana

“…Seedlings were grown for 10 days on modified Murashige and Skoog medium (K1 medium) [11] and treated either with KI medium for control or with 170 mM NaCI as described previously [10]. Axenic cultures of A. thaliana were set up in liquid medium according to [12] and the roots collected after 3 weeks of growth.…”

“…This result suggests that proline produced in leaves may be transported towards the flowers. Proline may have a role in the differentiation of flowers as well as in the desiccation processes of seeds [10,[35][36][37].…”

“…Recently, a cDNA showing high identity to the P5CS cDNA from V. aconitifolia was isolated from Arabidopsis thaliana [9]. As part of our efforts toward understanding the proline biosynthetic pathway in Arabidopsis and to unravel the role of proline in response to osmotic stress, we have previously cloned and characterized a cDNA and the corresponding gene encoding the second enzyme of the pathway, the P5C reductase [10].…”

Isolation of the Ornithine-δ-Aminotransferase cDNA and Effect of Salt Stress on Its Expression inArabidopsis thaliana1

“…Regulation of the glutamate route is relatively well documented: moth bean (Vigna aconitifolia) P5CS enzyme synthesized in Escherichia coli is allosterically inhibited by Pro (Hu et al, 1992). The stimulation of Pro biosynthesis under salt and water stress is also correlated with an increase in the levels of P5CR and P5CS mRNA (Hu et al, 1992;Verbruggen et al, 1993;Savoure et al, 1995;Yoshiba et al, 1995;Strizhof et al, 1997).…”

“…Aiming to understand the role of ␦-OAT in the Pro biosynthesis, our approach was to study ␦-OAT in Arabidopsis thaliana, for which the enzymes of the glutamate pathway have already been cloned (Verbruggen et al, 1993;Yoshiba et al, 1995;Strizhof et al, 1997) and to determine how ␦-OAT expression varies as a function of plant development after salt stress.…”