title: Flavonoids and darkness lower PCD in senescing Vitis vinifera suspension cell cultures.
abstract: Senescence is a key developmental process occurring during the life cycle of plants that can be induced also by environmental conditions, such as starvation and/or darkness. During senescence, strict control of genes regulates ordered degradation and dismantling events, the most remarkable of which are genetically programmed cell death (PCD) and, in most cases, an upregulation of flavonoid biosynthesis in the presence of light. Flavonoids are secondary metabolites that play multiple essential roles in development, reproduction and defence of plants, partly due to their well-known antioxidant properties, which could affect also the same cell death machinery. To understand further the effect of endogenously-produced flavonoids and their interplay with different environment (light or dark) conditions, two portions (red and green) of a senescing grapevine callus were used to obtain suspension cell cultures. Red Suspension cell Cultures (RSC) and Green Suspension cell Cultures (GSC) were finally grown under either dark or light conditions for 6 days.
  
  
  
  Darkness enhanced cell death (mainly necrosis) in suspension cell culture, when compared to those grown under light condition. Furthermore, RSC with high flavonoid content showed a higher viability compared to GSC and were more protected toward PCD, in accordance to their high content in flavonoids, which might quench ROS, thus limiting the relative signalling cascade. Conversely, PCD was mainly occurring in GSC and further increased by light, as it was shown by cytochrome c release and TUNEL assays.
  
  
  
  Endogenous flavonoids were shown to be good candidates for exploiting an efficient protection against oxidative stress and PCD induction. Light seemed to be an important environmental factor able to induce PCD, especially in GSC, which lacking of flavonoids were not capable of preventing oxidative damage and signalling leading to senescence.
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy.
authors: Alberto
authors: A
authors: Bertolini
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy.
authors: Elisa
authors: E
authors: Petrussa
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy.
authors: Sonia
authors: S
authors: Patui
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy.
authors: Marco
authors: M
authors: Zancani
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy.
authors: Carlo
authors: C
authors: Peresson
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy.
authors: Valentino
authors: V
authors: Casolo
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy.
authors: Angelo
authors: A
authors: Vianello
authors: Department of Agricultural, Food, Animal and Environmental Sciences, University of Udine, via delle Scienze, 91, 33100, Udine, Italy. enrico.braidot@uniud.it.
authors: Enrico
authors: 0000-0002-5415-3657
authors: E
authors: Braidot
mesh_terms: D017209:Apoptosis / Q000528:radiation effects*; D018929:Cell Culture Techniques; D003624:Darkness; D005419:Flavonoids / Q000378:metabolism*; D008027:Light; D015398:Signal Transduction; D027843:Vitis / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*
chemical_list: D005419:Flavonoids
keywords: Cell cultures; Flavonoids; PCD; Senescence; Vitis vinifera