Moreover, in order to prevent the photodamage effect
of reactive oxygen species (ROS), several photoprotective
mechanisms are involved for dissipating excess excitation,
such as a conversion state in the xanthophyll cycle, increased
photorespiration, and enhanced activity by antioxidant
systems under drought conditions (Wingler et al. 1999;
Munné-Bosch and Peñuelas 2004; Müller et al. 2006; Šircelj
et al. 2007; Peguero-Pina et al. 2008).