The resurrection plant Sporobolus stapfianus: An unlikely model for engineering enhanced plant biomass?

Abstract

The resurrection grass Sporobolus stapfianus Gandoger can rapidly recover from extended periods of time in the desiccated state (water potential equilibrated to 2% relative humidity) (Gaff and Ellis, Bothalia 11:305-308 1974; Gaff and Loveys, Transactions of the Malaysian Society of Plant Physiology 3:286-287 1993). Physiological studies have been conducted in S. stapfianus to investigate the responses utilised by these desiccationtolerant plants to cope with severe water-deficit. In a number of instances, more recent gene expression analyses in S. stapfianus have shed light on the molecular and cellular mechanisms mediating these responses. S. stapfianus is a versatile research tool for investigating desiccation-tolerance in vegetative grass tissue, with several useful characteristics for differentiating desiccation-tolerance adaptive genes from the many dehydration-responsive genes present in plants. A number of genes orthologous to those isolated from dehydrating S. stapfianus have been successfully used to enhance drought and salt tolerance in model plants as well as important crop species. In addition to the ability to desiccate and rehydrate successfully, the survival of resurrection plants in regions experiencing short sporadic rainfall events may depend substantially on the ability to tightly down-regulate cell division and cell wall loosening activities with decreasing water availability and then grow rapidly after rainfall while water is plentiful. Hence, an analysis of gene transcripts present in the desiccated tissue of resurrection plants may reveal important growth-related genes. Recent findings support the proposition that, as well as being a versatile model for devising strategies for protecting plants from water-loss, resurrection plants may be a very useful tool for pinpointing genes to target for enhancing growth rate and biomass production.

Plant Desiccation Tolerance and its Regulation in the Foliage of Resurrection “Flowering-Plant” Species

“…This has been addressed in Arabidopsis, where accumulated T6P under sink-limited stress conditions inhibits SnRK1 activity, and thus allows synthesis and growth to resume rapidly once the growth limiting stress conditions were alleviated [118]. A similar acceleration of growth is observed in S. stapfianus that has been through a dehydration cycle [36].…”

“…Induction of desiccation tolerance first becomes evident at~60% RWC in S. stapfianus (Table 3), a water content sufficiently low to produce large changes in the hydraulic pressure on the cell contents. A glycine rich protein (GRP) that may interact with WAK kinase is specifically expressed in desiccation tolerant tissue of S. stapfianus [36]. A similar GRP from C. plantagineum has been shown to interact with CpWAK1 [37].…”

The evolution of desiccation tolerance in angiosperm plants: a rare yet common phenomenon

“…The walls of dry cells are often folded, indicative of a plasticity that is thought to avoid mechanical damage to the drying wall, the protoplast and the contact between them (Farrant 2007). The plasticity would also assist the rapid growth seen in rehydrated resurrection grasses (Blomstedt et al 2010). The airdry leaves tolerate temperatures approaching 60 C and subfreezing temperatures of À80 C. The time-span over which air-dry leaves remain viable is impressive.…”

Orthodox Seeds and Resurrection Plants: Two of a Kind?

“…HDT (see Box 1; Fig. 1), such as B. hygrometrica, Craterostigma spp., H. rhodopensis, Myrothamnus flabellifolius, S. stapfianus, and Tripogon loliiformis, degrade only a small amount of Chl during dehydration (Farrant, 2000;Georgieva et al, 2007;Blomstedt et al, 2010;Mitra et al, 2013;Sárvári et al, 2014;Williams et al, 2015). These plants retain macro-level thylakoid structure, deactivating and activating partial components of the photosynthetic machinery in a specific order, which allows for coordinated shutdown and subsequent reinstatement of photosynthesis during drying and rehydration, respectively (Charuvi et al, 2015;Zia et al, 2016).…”