P5CDH affects the pathways contributing to Pro synthesis after ProDH activation by biotic and abiotic stress conditions

RIZZI YS; MONTEOLIVA M; FABRO G; GROSSO C; LARÓVERE LE; ALVAREZ ME

Frontiers in Plant Science

Frontiers

Año: 2015

lants facing adverse conditions usually alter proline (Pro) metabolism, generating4 changes that help restore the cellular homeostasis. These organisms synthesize Pro from5 glutamate (Glu) or ornithine (Orn) by two-step reactions that share ∆1 pyrroline-5-6 carboxylate (P5C) as intermediate. In the catabolic process, Pro is converted back into Glu7 using a different pathway that involves Pro dehydrogenase (ProDH), P5C dehydrogenase8 (P5CDH), and P5C as intermediate. Little is known about the coordination of the catabolic9 and biosynthetic routes under stress. To address this issue, we analyzed how P5CDH10 affects the activation of Pro synthesis, in Arabidopsis tissues that increase ProDH activity11 by transient exposure to exogenous Pro, or infection with Pseudomonas syringae pv.12 tomato. Wild type (Col-0) and p5cdh mutant plants subjected to these treatments were used13 to monitor the Pro, Glu and Orn levels, as well as the expression of genes from Pro14 metabolism. Col-0 and