Changes in Ethylene, ABA and Sugars Regulate Freezing Tolerance under Low-Temperature Waterlogging in Lolium perenne.

Barbara Jurczyk,Michał Dziurka,Ewa Pociecha,Izabela Kościk,Marcin Rapacz,Franciszek Janowiak

doi:10.3390/ijms22136700

Abstract

Plant overwintering may be affected in the future by climate change. Low-temperature waterlogging, associated with a predicted increase in rainfall during autumn and winter, can affect freezing tolerance, which is the main component of winter hardiness. The aim of this study was to elucidate the mechanism of change in freezing tolerance caused by low-temperature waterlogging in Lolium perenne, a cool-season grass that is well adapted to a cold climate. The work included: (i) a freezing tolerance test (plant regrowth after freezing); (ii) analysis of plant phytohormones production (abscisic acid [ABA] content and ethylene emission); (iii) measurement of leaf water content and stomatal conductance; (iv) carbohydrate analysis; and (v) analysis of Aco1, ABF2, and FT1 transcript accumulation. Freezing tolerance may be improved as a result of cold waterlogging. The mechanism of this change is reliant on multifaceted actions of phytohormones and carbohydrates, whereas ethylene may counteract ABA signaling. The regulation of senescence processes triggered by concerted action of phytohormones and glucose signaling may be an essential component of this mechanism.

Highlights

Extreme weather events are expected to occur more frequently owing to climate change
The study was focused on perennial ryegrass (Lolium perenne), a cool-season grass that is well adapted to a cold climate
Three genotypes of L. perenne showed an increase in freezing tolerance under waterlogging (Figure 1)

Summary

Introduction

Extreme weather events are expected to occur more frequently owing to climate change. Intensity, and amount of heavy precipitation events are predicted at high latitudes of the Northern Hemisphere and potentially raise the possibility of flooding [1,2]. The increase in autumn and winter precipitation as well as winter warming events leading to snow melt may change the risk of low-temperature waterlogging. Under such conditions, a plant’s overwintering capability is uncertain [3]. Hypoxic or even anoxic conditions are the primary constraint associated with flooding. The risk of oxygen deficiency in waterlogged soil increases under high temperatures [4]

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Conclusion