Noninvasive Methods to Detect Reactive Oxygen Species as a Proxy of Seed Quality

ROS homeostasis is crucial to maintain radical levels in a dynamic equilibrium within
physiological ranges. Therefore, ROS quantification in seeds with different germination performance
may represent a useful tool to predict the efficiency of common methods to enhance seed vigor,
such as priming treatments, which are still largely empirical. In the present study, ROS levels were
investigated in an experimental system composed of hydroprimed and heat-shocked seeds, thus
comparing materials with improved or damaged germination potential. A preliminary phenotypic
analysis of germination parameters and seedling growth allowed the selection of the best-per-forming
priming protocols for species like soybean, tomato, and wheat, having relevant agroeconomic value.
ROS levels were quantified by using two noninvasive assays, namely dichloro-dihydro-fluorescein
diacetate (DCFH-DA) and ferrous oxidation-xylenol orange (FOX-1). qRT-PCR was used to assess
the expression of genes encoding enzymes involved in ROS production (respiratory burst oxidase
homolog family, RBOH) and scavenging (catalase, superoxide dismutase, and peroxidases). The
correlation analyses between ROS levels and gene expression data suggest a possible use of these
indicators as noninvasive approaches to evaluate seed quality. These findings are relevant given
the centrality of seed quality for crop production and the potential of seed priming in sustainable
agricultural practices.