Water Deficit Affects Primary Metabolism Differently in Two Lolium multiflorum/Festuca arundinacea Introgression Forms with a Distinct Capacity for Photosynthesis and Membrane Regeneration

Abstract

Understanding how plants respond to drought at different levels of cell metabolism is an important aspect of research on the mechanisms involved in stress tolerance. Furthermore, a dissection of drought tolerance into its crucial components by the use of plant introgression forms facilitates to analyze this trait more deeply. The important components of plant drought tolerance are the capacity for photosynthesis under drought conditions, and the ability of cellular membrane regeneration after stress cessation. Two closely related introgression forms of Lolium multiflorum/Festuca arundinacea, differing in the level of photosynthetic capacity during stress, and in the ability to regenerate their cellular membranes after stress cessation, were used as forage grass models in a primary metabolome profiling and in an evaluation of chloroplast 1,6-bisphosphate aldolase accumulation level and activity, during 11 days of water deficit, followed by 10 days of rehydration. It was revealed here that the introgression form, characterized by the ability to regenerate membranes after rehydration, contained higher amounts of proline, melibiose, galactaric acid, myoinositol and myo-inositol-1-phosphate involved in osmoprotection and stress signaling under drought. Moreover, during the rehydration period, this form also maintained elevated accumulation levels of most the primary metabolites, analyzed here. The other introgression form, characterized by the higher capacity for photosynthesis, revealed a higher accumulation level and activity of chloroplast aldolase under drought conditions, and higher accumulation levels of most photosynthetic products during control and drought periods. The potential impact of the observed metabolic alterations on cellular membrane recovery after stress cessation, and on a photosynthetic capacity under drought conditions in grasses, are discussed.

Brassinosteroids improve photosystem II efficiency, gas exchange, antioxidant enzymes and growth of cowpea plants exposed to water deficit

“…Water deficit is considered the main abiotic stress that limits agricultural production worldwide (Inman-Bamber and Smith 2005). This stress often causes molecular, biochemical and physiological modifications (Marinho et al 2016;Boughalleb et al 2016;Pereira et al 2016) that negatively affect metabolism (Perlikowski et al 2016), reducing the growth and development (Mansori et al 2015), as well as the crop yield . Water limitations reduce the water potential (Fernandes-Silva et al 2016), lower the photosynthetic activity (Bertolli et al 2012), affect stomatal closing (Spinelli et al 2016), affect the accumulation of reactive oxygen species (Yi et al 2016), cause cell damages (Toscano et al 2016) and depending on the exposure time and intensity, can cause plant death (Chaves et al 2003;Shao et al 2008).…”

To cope with drought: two forage grass species – Festuca arundinacea and F. glaucescens can activate similar survival strategies although they differ with molecular response

“…This enzyme was shown to be crucial for the efficiency of the Calvin cycle under drought conditions in our earlier experiment performed on L. multiflorum/F. arundinacea introgression forms (8,16). However, the higher abundance of pFBA during drought period was followed by its higher activity only in case of the Fg-HDR genotype.…”

“…(2016) (8). The amount of produced trioses in the pFBA assay was read according to the standard curve and after calculations of glyceraldehyde mg produced by 1 g of plant sample during 1 h.…”

“…Its efficiency can be restricted by both stomatal and non-stomatal mechanisms. Stomata closing declines CO 2 availability, whereas among the non-stomatal mechanism, a reduction of Calvin cycle efficiency was indicated to be crucial (8,14,15,16).…”

“…Our previous studies revealed that Festuca species could be successfully used as models to precisely dissect mechanisms of resistance to a wide range of abiotic stresses in a group of forage grasses (e.g. 3,4,5,6,7,8,9).…”