Two Festuca Species—F. arundinacea and F. glaucescens—Differ in the Molecular Response to Drought, While Their Physiological Response Is Similar

Abstract

Impact of photosynthetic and antioxidant capacities on drought tolerance of two closely related forage grasses, Festuca arundinacea and Festuca glaucescens, was deciphered. Within each species, two genotypes distinct in drought tolerance were subjected to a short-term drought, followed by a subsequent re-watering. The studies were focused on: (i) analysis of plant physiological performance, including: water uptake, abscisic acid (ABA) content, membrane integrity, gas exchange, and relative water content in leaf tissue; (ii) analysis of plant photosynthetic capacity (chlorophyll fluorescence; gene expression, protein accumulation, and activity of selected enzymes of the Calvin cycle); and (iii) analysis of plant antioxidant capacity (reactive oxygen species (ROS) generation; gene expression, protein accumulation and activity of selected enzymes). Though, F. arundinacea and F. glaucescens revealed different strategies in water uptake, and partially also in ABA signaling, their physiological reactions to drought and further re-watering, were similar. On the other hand, performance of the Calvin cycle and antioxidant system differed between the analyzed species under drought and re-watering periods. A stable efficiency of the Calvin cycle in F. arundinacea was crucial to maintain a balanced network of ROS/redox signaling, and consequently drought tolerance. The antioxidant capacity influenced mostly tolerance to stress in F. glaucescens.

Adjustment of Photosynthetic and Antioxidant Activities to Water Deficit Is Crucial in the Drought Tolerance of Lolium multiflorum/Festuca arundinacea Introgression Forms

“…However, we did not observe leaf rolling in the case of these plants, which was shown to be a characteristic trait of F. arundinacea and F. glaucescens under the same stress conditions [45]. Although RWC in the HDT and LDT plants decreased at the advanced stage of the drought, which was previously observed in F. arundinacea and F. glaucescens [45], and in the other L. multiflorum/F. arundinacea introgression forms [46], the analyzed forms did not differ in the intensity of water loss.…”

“…During the short-drought period applied in the environmental chamber, both introgression forms revealed symptoms of physiological disturbances, including loss of leaf turgor ( Figure S2). However, we did not observe leaf rolling in the case of these plants, which was shown to be a characteristic trait of F. arundinacea and F. glaucescens under the same stress conditions [45]. Although RWC in the HDT and LDT plants decreased at the advanced stage of the drought, which was previously observed in F. arundinacea and F. glaucescens [45], and in the other L. multiflorum/F.…”

“…On the other hand, genotypes of F. arundinacea distinct in their levels of drought tolerance showed no differences with respect to ABA dynamics and contents under similar experimental conditions [45]. Interestingly, only the LDT genotype of F. glaucescens revealed a significant increase in ABA accumulation at the advanced time point of the drought period [45]. Thus, we demonstrated here that the introgression forms investigated in the current research were characterized by unique physiological traits compared with the other plant materials used in our earlier studies and could be valuable models to deepen our understanding of drought tolerance and to indicate novel components of this tolerance in forage grasses.…”

“…Thus, herein we applied another pair of introgression forms, which could serve as useful plant models to identify yet unrecognized cellular components involved in the mechanisms of drought tolerance in forage grasses. To approve our hypothesis, we performed the research on the HDT and the LDT introgression forms selected in the field, applying short-term drought treatment in pots, thus in environmental conditions preventing unlimited root development, similarly to our earlier studies [45,46].…”

Plant Cell and Organism Development

“…The article by Lechowicz et al [33] is a study of two closely related grasses, Festuca arundinacea and F. glaucescens, with regard to their response to a short-term drought, followed by a subsequent re-watering under a simulation in pots. This comprehensive analysis involved various aspects of plant physiological performance, photosynthetic capacity and antioxidant capacity.…”