Manipulation of oxidative stress responses as a strategy to generate stress-tolerant crops. From damage to signaling to tolerance

GÓMEZ, RODRIGO; VICINO, PAULA; CARRILLO, NÉSTOR; LODEYRO, ANABELLA F.

CRITICAL REVIEWS IN BIOTECHNOLOGY

TAYLOR & FRANCIS INC

Lugar: Londres; Año: 2019

0738-8551

Plants exposedto hostile environmental conditions such as drought or extreme temperaturesusually undergo oxidative stress, which has long been assumed to significantlycontribute to the damage suffered by the organism. Reactive oxygen species(ROS) overproduced under stress conditions were proposed to destroy membrane lipidsand to inactivate proteins and photosystems, ultimately leading to cell death.Accordingly, considerable effort has been devoted over the years to improvestress tolerance by strengthening antioxidant and dissipative mechanisms.Although the notion that ROS cause indiscriminate damage in vivo has been progressively replaced by the alternative conceptthat they act as signaling molecules directing critical plant developmental andenvironmental responses including cell death, the induction of genes encodingantioxidant activities is commonplace under many environmental stresses,suggesting that their manipulation still offers promise. The features andconsequences of ROS effects depend on the balance between various interactingpathways including ROS synthesis and scavenging, energy dissipation,conjugative reactions and eventually reductive repair. They represent as manypossibilities for genetic manipulation. We report herein a comprehensive surveyof transgenic plants in which components of the ROS-associated pathways wereoverexpressed, and of the stress phenotypes displayed by the correspondingtransformants. Genetic engineering of different stages of ROS metabolism suchas synthesis, scavenging and reductive repair revealed a strong correlationbetween down-regulation of ROS levels and increased stress tolerance in plantsgrown under controlled conditions. Field assays are instead scarce, and eagerlyrequired to assess the possible application of this strategy to agriculture.