Rubisco and some chaperone protein responses to water stress and rewatering at early seedling growth of drought sensitive and tolerant wheat varieties

Abstract

Four wheat varieties differing in their drought tolerance were subjected to severe but recoverable water stress at seedling stage. Growth parameters, leaf water deficit (WD) and electrolyte leakage (EL) were used to evaluate the stress intensity and the extent of recovery. The physiological response of the varieties was quite similar under severe drought. Leaf protein patterns and levels of some individual proteins relevant to ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) maintenance were studied in control, stressed and recovering plants by electrophoresis and immunoblotting. The bands representing Rubisco large subunit (RLS), N-and C-terminus of RLS, Rubisco activase (RA) and Rubisco binding protein (RBP, cpn 60), as well as the chaperone and proteolytic subunits of the Clp protease complex were identified using polyclonal antibodies. Under drought conditions RLS, Clp proteases and especially RBP were enhanced, whereas the RA band was only slightly affected. The drought tolerant varieties had higher RBP content in the controls and drought treated plants. Its concentration could be a potential marker for drought tolerance.

Expression of drought tolerance genes in tropical upland rice cultivars (Oryza sativa)

“…The gene LOC_Os01g42380.1 has an ortholog in A. thaliana, AT1G02520.1, which is part of the ABC family (TAIR, 2014). The gene LOC_Os03g04970.1-similar to Arabidopsis mitochondrial chaperonin 60 (AT3G23990.1), has an essential function in protein homeostasis under normal conditions and is highly responsive to various stresses (Demirevska et al, 2008).…”

Drought, high temperature, and their combination affect ultrastructure of chloroplasts and mitochondria in wheat (Triticum aestivumL.) leaves

“…Two varieties of winter wheat (Triticum aestivum L.) differing in their drought tolerance were selected for ultrastructural examination: Katya (the most drought-tolerant Bulgarian variety) and Sadovo (disease resistant and more susceptible to water stress) (Simova-Stoilova et al 2006;Demirevska et al 2008;Vassileva et al 2009). Plants were grown in pots containing 400 g cinnamon soil (pH 6.2), optimally fertilized with N, P, and K, under a light intensity of 200 mmol m -2 s -1 at 21Á258C and a 14-h photoperiod.…”

“…The level of drought stress was monitored as described in previous reports (Simova-Stoilova et al 2006;Demirevska et al 2008). Control plants and plants submitted only to hightemperature treatment were regularly watered.…”

“…Proteomic and ultrastructural studies of plastoglobules confirm their essential role in protecting thylakoid membranes from oxidative damages by intensive synthesis and storage of lipids (such as carotenoids, tocopherol, and plastoquinone) and plastoglobulespecific proteins with both enzymatic and structural functions (Kessler et al 1999;Austin et al 2006;Vidi et al 2006). Plant stress responses to individual and combined application of drought and high temperature are often species specific, but there are also differences among varieties and cultivars within a species Demirevska et al 2008;Vassileva et al 2011). Changes in water and temperature regimes affect plant structure and functions differently, as drought-sensitive cultivars are more vulnerable to stress damages than drought-tolerant cultivars (Ristic and Cass 1991;Vassileva et al 2009).…”

“…protein patterns and levels of some individual proteins, relevant to the key photosynthetic enzyme Rubisco (Demirevska et al 2008;Grigorova et al 2011a). The higher content of Rubisco large and small subunits and other chaperone proteins that are of crucial importance for Rubisco stability and activity could be related to better functioning of Katya in adverse environmental conditions.…”