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

Katarzyna Lechowicz,Joanna Majka,Arkadiusz Kosmala,Magdalena Arasimowicz-Jelonek,Marcin Rapacz,Adam Augustyniak,Dawid Perlikowski,Izabela Pawłowicz

doi:10.3390/ijms21093174

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.

Highlights

Water deficit is one of the main environmental factors that affects plant growth and development, and significantly reduces the yield of many crop species
A stable efficiency of the Calvin cycle in F. arundinacea was crucial to maintain a balanced network of reactive oxygen species (ROS)/redox signaling, and drought tolerance
Festuca arundinacea genome comprised of 42 chromosomes and was allohexaploid, while tetraploid F. glaucescens genome comprised of 28 chromosomes

Summary

Introduction

Water deficit is one of the main environmental factors that affects plant growth and development, and significantly reduces the yield of many crop species. Forage grasses from Lolium and Festuca genera are among the most important species in temperate regions. In F. arundinacea, drought tolerance is mainly associated with drought avoidance, which relies on a development of deep root system, leaf rolling, and a rapid stomatal closure during the prolonged drought periods in the field conditions [10,12]. Our earlier experiments revealed that F. arundinacea could develop a metabolic adjustment strategy during short but severe drought periods [5,6]. F. glaucescens was described earlier as a species characterized mainly by a metabolism deceleration and a reduction of growth, associated with ‘a quiescence’ under drought conditions, followed by a further regrowth after stress cessation, which enables it to survive and to resume metabolism, following irrigation [13,14]. The knowledge about molecular basis of drought tolerance is, strongly limited for this species and requires detailed research

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Conclusion