Vegetative desiccation tolerance in Eragrostiella brachyphylla: biochemical and physiological responses

Abstract

Eragrostiella brachyphylla is an angiosperm desiccation-tolerant resurrection plant, which can survive during desiccation in the air-dry state and recover completely on availability of water. The present study was conducted to understand the vegetative desiccation tolerance of Eragrostiella brachyphylla by evaluating its ability to recover the physiological, biochemical and morphological functions post desiccation. In order to understand the responses of Eragrostiella brachyphylla to desiccation and subsequent rehydration experiments were conducted in the hydrated state (HS), desiccated state (DS) and rehydrated state (RS). Scanning electron microscopy revealed significant changes between the three stages in the internal ultra-structures of leaves and stems. Compared to the other states, photosynthetic parameters such as chlorophyll a, chlorophyll b, total chlorophylland total carotenoid contents decreased significantly in the desiccated state. Superoxide radical (O2 À) content also increased, resulting in an oxidative burst during desiccation. Consequently, antioxidant enzymes such as catalase (CAT) superoxide dismutase (SOD) peroxidase (APX) and glutathione reductase (GR) activities were found to be significantly elevated in the desiccated state to avoid oxidative damage. Increased malondialdehyde (MDA) content and relative electrolyte leakage (REL) during desiccation provide evidence for membrane damage and loss of cell-wall integrity. During desiccation, the contents of osmolytes represented by sucrose and proline were found to increase to maintain cell structure integrity. After rehydration, all physiological, biochemical and morphological properties remain unchanged or slightly changed when compared to the hydrated state. Hence, we believe that these unique adaptations contribute to the remarkable desiccation-tolerance property of this plant.

Desiccation as a Post-maturation Treatment Helps Complete Maturation of Norway Spruce Somatic Embryos: Carbohydrates, Phytohormones and Proteomic Status

“…These results indicate that starch represents a transient energy source in both SEs and ZEs. Most importantly, they imply the preparation of the embryos in a dry state, where the starch content is low after conversion into sugars such as sucrose and RFOs, which helps to prevent lethal effects of water stress ( Yathisha et al, 2020 ).…”

Tardigrade CAHS Proteins Act as Molecular Swiss Army Knives to Mediate Desiccation Tolerance Through Multiple Mechanisms

“…1 Anhydrobiosis can be a normal stage of life, as in the case of plant seeds 2,3 , or it can be a response to an environmental loss of water. [4][5][6][7] In many organisms capable of anhydrobiosis, nonreducing sugars such as sucrose in plants 8 or trehalose in many organisms [9][10][11][12][13] are accumulated intracellularly during the process of desiccation. The acquisition of simple polysaccharides was long thought to be an essential feature in desiccation tolerance.…”

“…Many desiccation-tolerant organisms protect their cells from drying induced damage by accumulating non-reducing sugars, such as sucrose 5 or trehalose. 6–10 The enrichment of disaccharides was long thought to be a universal feature of desiccation tolerance.…”

Desiccation‐tolerant vascular plants from Western Ghats, India: review, updated checklist, future prospects and new insights

“…Amongst lycophytes, Selaginella (Selaginellaceae) is a commonly occurring genus on rock outcrops. Globally, 25 species of Selaginella are known for their DT properties (Alpert 2000, Kessler and Siorak 2007, Yu et al 2017, Rabarimanarivo et al 2019, Shivaraj et al 2020, Marks et al 2021). Recently, S. bryopteris (Deeba et al 2009) and Selaginella brachystachya (Shivaraj et al 2020) were reported from India as DT species.…”

“…Watve (2005) also highlighted the importance of this region in the knowledge of Indian DT plants. Apart from these two works from WG, a few attempts from other Indian regions (Deeba et al 2009, Sharma et al 2015, Lubaina et al 2016, Banupriya et al 2020, Shivaraj et al 2020, 2021) have been carried out to document DT plants. However, a comprehensive documentation of Indian DT species is altogether lacking.…”