Identifying resurrection genes through the differentially expressed genes between Selaginella tamariscina (Beauv.) spring and Selaginella moellendorffii Hieron under drought stress

Abstract

Selaginella tamariscina (Beauv.) spring, a primitive vascular resurrection plant, can survive extreme drought and recover when water becomes available. To identify drought-inducible genes and to clarify the molecular mechanism of drought tolerance, a comparative transcriptional pattern analysis was conducted between S. tamariscina and Selaginella moellendorffii Hieron (drought sensitive). 133 drought related genes were identified, including 72 functional genes and 61 regulatory genes. And several drought responsive reactions, such as antioxidant activity, osmotic balance, cuticle defense and signal transduction were highlighted in S. tamariscina under drought. Notably, besides peroxidase, catalase and L-ascorbate oxidase genes, DEGs associated with phenylalanine metabolism and polyamine catabolism could be alternative ways to enhance antioxidant ability in S. tamariscina. DEGs related to soluble carbohydrate metabolism, late embryogenesis abundant protein (LEA) and aquaporin protein (AQP) confirmed that osmotic adjustment could resist drought during desiccation. DEGs involved in xyloglucan metabolic process, pectin metabolic process and cutin biosynthesis may also contribute to drought tolerance of S. tamariscina by cuticle defense. Drought-responsive genes encoding protein kinases, calcium sensors, transcription factors (TFs) and plant hormones also help to drought resistance of S. tamariscina. The preliminary validation experiments were performed and the results were consistent with our hypothetical integrated regulatory network. The results of this study provide candidate resurrection genes and an integrated regulatory network for further studies on the molecular mechanisms of stress tolerance in S. tamariscina.

Physiological and metabolic changes in Selaginella tamariscina in response to desiccation and resurrection

“…Proteomic analysis identi ed many desiccation-responsive proteins in S. tamariscina associated with photosynthesis, antioxidant defense, and translational modi cation (Wang et al 2010). Similar ndings were showed in the study of Gu et al who found that multiple genes involved in antioxidant defense system, polyamine and carbohydrate metabolism, and stress-defensive protein biosynthesis such as dehydrins and aquaporins could contribute to desiccation tolerance of S. tamariscina due to bene cial roles of these metabolites and proteins in antioxidant, OA, and signal transduction (Gu et al 2019). In addition, abscisic acid signaling was one of important desiccation tolerance strategies in S. tamariscina (Liu et al 2008;Xu et al 2018).…”

“…. It has been reported that enhanced carbohydrate metabolism could be a positive strategy for adaptation to desiccation through comparing differential genes in drought-tolerant S. tamariscina and drought-sensitive S. moellendor i(Gu et al 2019). Desiccation-tolerant S. lepidophylla could also accumulate more sugars and sugar alcohols than desiccation-sensitive S. moellendor i when leaf RWC declined from 100-50%(Yobi et al 2012).…”

Plant behaviour: an evolutionary response to the environment?

“…superoxide dismutase, peroxidase, catalase and glutathione reductase) and the accumulation of osmolites ( e.g. proline and soluble sugars) to counteract the mechanical and oxidative stresses induced by drought (Xu et al, 2018; Gu et al, 2019). In particular, abscisic acid regulates drought resistance genes in plants and is involved in the accumulation of sugars, the regulation of closure of stomata and in redox balance (Liu et al, 2008; Liu et al, 2019).…”

What Do We Know About the Genetic Basis of Seed Desiccation Tolerance and Longevity?

“…Interestingly, LEA-like proteins are also found in a variety of organisms, such as anhydrobiotic nematodes [111,112], brine shrimp [113], rotifers [114,115], and some bacterial species [108]. Although LEAs were first described in embryonic tissues, thirty years of intensive research showed that the expression of LEA genes is also significantly induced in vegetative organs (i.e., callus, flowers, roots, leaves, buds) under abiotic stresses such as desiccation, salinity, and cold [116][117][118][119][120].…”