Identification of Extracellular Matrix Proteins of Rice (Oryza sativa L.) Involved in Dehydration-Responsive Network: A Proteomic Approach

Abstract

Water-deficit or dehydration impairs almost all physiological processes and greatly influences the geographical distribution of many crop species. It has been postulated that higher plants rely mostly on induction mechanisms to maintain cellular integrity during stress conditions. Plant cell wall or extracellular matrix (ECM) forms an important conduit for signal transduction between the apoplast and symplast and acts as front-line defense, thereby playing a key role in cell fate decision under various stress conditions. To better understand the molecular mechanism of dehydration response in plants, four-week-old rice seedlings were subjected to progressive dehydration by withdrawing water and the changes in the ECM proteome were examined using two-dimensional gel electrophoresis. Dehydration-responsive temporal changes revealed 192 proteins that change their intensities by more than 2.5-fold, at one or more time points during dehydration. The proteomic analysis led to the identification of about 100 differentially regulated proteins presumably involved in a variety of functions, including carbohydrate metabolism, cell defense and rescue, cell wall modification, cell signaling and molecular chaperones, among others. The differential rice proteome was compared with the dehydration-responsive proteome data of chickpea and maize. The results revealed an evolutionary divergence in the dehydration response as well as organ specificity, with few conserved proteins. The differential expression of the candidate proteins, in conjunction with previously reported results, may provide new insight into the underlying mechanisms of the dehydration response in plants. This may also facilitate the targeted alteration of metabolic routes in the cell wall for agricultural and industrial exploitation.

Cell water content and lignification in maize regulated by rhizobacteria under salinity

“…PAL, which catalyzes the deamination of phenylalanine to trans-cinnamate, was shown to be regulated upon stress exposure. In the present study, both the bacterial isolate and salinity enhanced PAL activity, is supported by Pandey et al (2010), who reported an increased level of PAL following drought stress in rice.…”

“…The PAL enzyme play positive role plant cell wall lignification and down-regulation of PAL enzyme effect the lignification process in plants (Ogras et al, 2000). Pandey et al (2010) in a proteomic study, reported an enhanced PAL activity under drought stress in rice. Terzi et al (2013) also reported that, PAL activity increased up to 16-fold and also effects the polyphenol oxidase activities, ionically wall-bound peroxidase and lignin content in grey-maranta (Ctenanthe setosa) when exposed to drought stress.…”

Genetic, proteomic and metabolic analysis of the regulation of energy storage in rice seedlings in response to drought

“…However, studies using tobacco have shown the opposite regulation of this pathway during drought-induced and heat-induced stress [64]. This evolutionary divergence in stress responses among different plant species has also been shown by previous studies [22,23].…”

“…Choudhary et al [22] analyzed drought responsive nuclear proteins in rice and revealed coordinated responses between both regulatory and functional proteins. Pandey et al [23] reported differentially regulated proteins in the extracellular matrix that are involved in carbohydrate metabolism, cell defense and rescue, cell wall modification, cell signaling, and molecular chaperones. Integrated analysis of transcriptomics, proteomics and metabolomics, which is key to the study of rice proteomics [24], provides a more effective study of regulatory mechanisms in plants.…”

Plant proteomics in India and Nepal: current status and challenges ahead

“…For analysis of dehydration stress, proteomes of the extracellular matrix (ECM) and nucleus have been analyzed in rice (Pandey et al 2010) and chickpea .…”