Proteome response of Elymus elongatum to severe water stress and recovery

Abstract

Tall wheatgrass (Elymus elongatum Host) is a drought-tolerant, cool-season forage grass native to Iran. A proteomic approach has been applied to identify mechanisms of drought responsiveness and tolerance in plants undergoing vegetative stage drought stress and then recovery after rewatering. Uniformed clones were reproduced from a parent plant collected from Brojen (central region of Iran). Clones were grown in pots and drought was initiated by withholding water for 16 d. The leaf samples were taken in triplicate from both stressed/rewatered plants and continuously watered controls at five times: (i) 75% FC, (ii) 50% FC, (iii) 25% FC, (iv) 3 d after rewatering, and (v) 14 d after rewatering. Changes in the proteome pattern of shoots were studied using two-dimensional gel electrophoresis. Following the 16 d water stress, both shoot dry weight and leaf width decreased up to 67% compared with the well-watered plants, whereas proline content increased up to 20-fold. Leaf relative water contents (RWC) also declined from 85% to 24%. Out of about 600 protein spots detected on any given two-dimensional gel, 58 protein spots were reproducibly and significantly changed during drought stress and recovery. Only one protein (abscisic acid- and stress-inducible protein) showed significant changes in expression and position in response to severe drought. The fifty-eight responsive proteins were categorized in six clusters including two groups of proteins specifically up- and down-regulated in response to severe drought stress. Eighteen proteins belonging to these two groups were analysed by liquid chromatography tandem mass spectrometry leading to the identification of 11 of them, including the oxygen-evolving enhancer protein 2, abscisic acid- and stress-inducible protein, several oxidative stress tolerance enzymes, two small heat shock proteins, and Rubisco breakdown. The results suggest that E. elongatum may tolerate severe drought stress by accumulating proline and several proteins related to drought-stress tolerance. Recovery after rewatering might be another mechanism by which plants tolerate erratic rainfall in semi-arid regions.

Salt stress responses in Populus cathayana Rehder

“…In our study, four fragments of the Rubisco large subunit (spots 21, 27, 28, and 34) were up-regulated. It is possible that the increased abundance of protein fragments may have resulted from the breakdown of proteins generated by ROS or occurring during protein solubilization [11]. In this study, the breakdown of the Rubisco protein appears to be related to the decrease of the CO 2 assimilation rate.…”

“…The photosystem II (PSII) oxygen-evolving complex protein has been found to increase in rice in response to salt [2] and drought [6]. The expressions of antioxidant enzymes are up-regulated upon some abiotic stress, including, e.g., responses in various organs, tissues, cells and organelles in the model plant Arabidopsis [5,7,8], responses to drought stress in maritime pine [9], sugar beet [10], rice [6], Elymus elongatum [11] and wheat [12], responses to salt stress in rice [1] and S. aegyptiaca [3], and responses in poplar to heat stress [13] and ozone exposure [14].…”

Physiological, biochemical and mineral dimensions of green beangenotypes depending on Zn priming and salinity

“…When osmotic dehydration takes place, it decreases osmotic and water potential of cell and causes cell volume and expansion ratio to decrease. As a result of a decreasing transpiration, dryness that occurs in stem and leaves of the plant leads to plant weight loss (Gazanchian et al, 2007).…”

The effect of foliar application of methanol on sugar beet (Beta vulgaris L.) plants grown in drought conditions

“…In the present study, water de cit stress increased chlorophyll content in the leaves. Drought may initially inhibit leaf growth and development [Gazanchian et al 2007], and although chlorophyll content is closely associated with leaf development, response patterns of cell number and size [Lecoeur et al 1995] and chlorophyll content to water stress depend on the period of leaf development. At the cellular level, moderate water de cits (mild stress) had opposite effects on cell number and cell size, but more severe de cits reduced both variables [Aguirrezabal et al 2006].…”