Surviving metabolic arrest: photosynthesis during desiccation and rehydration in resurrection plants

Abstract

Photosynthesis is the key process that is affected by dehydration in plants. Desiccation-tolerant resurrection plants can survive conditions of very low relative water content. During desiccation, photosynthesis is not operational, but is recovered within a short period after rehydration. While homoiochlorophyllous resurrection plants retain their photosynthetic apparatus during desiccation, poikilochlorophyllous resurrection species dismantle chloroplasts and degrade chlorophyll but resynthesize them again during rehydration. Dismantling the chloroplasts avoids the photooxidative stress in poikilochlorophyllous resurrection plants, whereas it is minimized in homoiochlorophyllous plants through the synthesis of antioxidant enzymes and protective proteins or metabolites. Although the cellular protection mechanisms in both of these species vary, these mechanisms protect cells from desiccation-induced damage and restore photosynthesis upon rehydration. Several of the proteins synthesized during dehydration are localized in chloroplasts and are believed to play major roles in the protection of photosynthetic structures and in recovery in resurrection species. This review focuses on the strategies of resurrection plants in terms of how they protect their photosynthetic apparatus from oxidative stress during desiccation without membrane damage and with full recovery during rehydration. We review the role of the dehydration-induced protection mechanisms in chloroplasts and how photosynthesis is restored during rehydration.

A footprint of desiccation tolerance in the genome of Xerophyta viscosa

“…Thus, this overlap points to similarities between seed-and vegetative-DT 37 . In both systems, metabolism is shut down in an orderly manner and protection mechanisms activated 30,38,39 . Moreover, upon dehydration, both in seeds and in poikilochlorophyllous resurrection species, chloroplasts are disassembled and chlorophyll degraded.…”

Induced expression of Xerophyta viscosa XvSap1 gene greatly impacts tolerance to drought stress in transgenic sweetpotato

“…Plant drought stress involve intricate regulatory processes that control water flux and cellular osmotic modification through the biosynthesis of osmoprotectants (Golldack et al 2014). ‘Resurrection plants’ survive dehydration (losing over 90% of their water content) of their vegetative tissues to air dry state for extended periods and recover complete metabolic state after rehydration (Challabathula et al 2016). These resurrection plants could serve as ideal models for ultimate design of important crops with enhanced stress tolerance.…”

Orthodox Seeds and Resurrection Plants: Two of a Kind?

“…In HDT, the leaf area exposed to light (for example) is reduced via leaf curling, the presence of reflective hairs, and anthocyanin accumulation ( Fig. 1; Challabathula et al, 2016;Farrant et al, 2017). On the other hand, under dehydration stress, PDT (see Box 1; Fig.…”

“…The uncoupling of carbon fixation from electron transport results in the generation of massive amounts of reactive oxygen species (ROS; Fig. 1; for review, see Challabathula et al, 2016;Rogers and Munné-Bosch, 2016). HDT (see Box 1; Fig.…”