A proteomic analysis of cold stress responses in rice seedlings

Abstract

Using proteomic analysis, an investigation aimed at a better understanding of the molecular adaptation mechanisms of cold stress was carried out in rice (Oryza sativa). The seedlings were exposed to a progressively low temperature stress treatment from normal temperature to 15, 10, and 5 degrees C. Proteins were extracted from the leaves collected from both control and stressed seedlings. By fractionation, approximately 1700 protein spots were separated and visualized on CBB-stained 2-D gels. Sixty protein spots were found to be up-regulated in responding to the progressively low temperature stress and displayed different dynamic patterns. As an initial work, 41 of these proteins were identified using MALDI-TOF MS or ESI/MS/MS. These cold responsive proteins, besides two proteins of unknown function, include four factors of protein biosynthesis, four molecular chaperones, two proteases, and eight enzymes involved in biosynthesis of cell wall components, seven antioxidative/detoxifying enzymes, and proteins linked to energy pathway, as well as a protein involved in signal transduction. The functional proteomes illuminate the facts, at least in plant cell, that protein quality control mediated by chaperones and proteases and enhancement of cell wall components play important roles in tolerance to cold stress. Using TargetP program, the subcellular localization of the identified proteins was analyzed. Proteins (43.9%) were predicted to be located in the chloroplasts, implying that chloroplast proteome is virtually subjective to cold stress. The physiological implications, revealed from the experimental data, are discussed in context of a complex metabolic network in plant cells responsive to cold stress.

A proteomic approach in analyzing heat‐responsive proteins in rice leaves

“…Similar to our results, a gradual up-regulation of this enzyme has also been found in Populus leaves [5] and rice caryopses [3] exposed to heat stress. In addition to heat stress, it also is evident that thioredoxin h was up-regulated in rice leaves in response to cold stress [18,19,38]. These results indicate that thioredoxin h may be used as a biomarker for thermal stress; however, more research is needed in order to validate this hypothesis.…”

“…UGPase is responsible for the synthesis and pyrophosphorolysis of UDP-glucose, the key precursor of sucrose and cell wall components [36]. The up-regulation of UGPase activity, under cold stress, has already been demonstrated in Populus [37] and rice [38]. In carbohydrate metabolism, the pyruvate dehydrogenase complex (PDC) plays a crucial role by transferring carbon from glycolysis to the TCA cycle, and transketolase is one of the key enzymes for the synthesis of sugar-phosphate intermediates in the reductive and oxidative pentose phosphate pathways.…”

Gel-based proteomics approach for detecting low nitrogen-responsive proteins in cultivated rice species

“…It also possesses regions associated with the AAA-superfamily of ATPases, having a wide variety of cellular activities, including membrane fusion, proteolysis and DNA replication, and the peptidase family M41. Its role remains undefined in the low N response, but it may be part of a protein synthesis and quality control in stressed leaf as discussed previously (Cui et al, 2005).…”

Identification of aluminum‐responsive proteins in rice roots by a proteomic approach: Cysteine synthase as a key player in Al response

“…Over the past years, the proteomic approach has been applied to analyze the proteins involved in various stress responses in plants, such as drought [13], salinity [14,15], and cold [10,16]. To the best of our knowledge, there are no reports, to date, addressing the identification of Al-responsive proteins from plants using proteomic approach, not even using conventional biochemical protocols.…”