A proteomic approach to analyze salt‐responsive proteins in rice leaf sheath

Abstract

To examine the response of rice to salt stress, changes in protein expression were analyzed using a proteomic approach. To investigate dose‐ and time‐dependent responses, rice seedlings were exposed to 50, 100 and 150 mM NaCl for 6 to 48 h. Proteins were extracted from leaf sheath and separated by two‐dimensional polyacrylamide gel electrophoresis. Eight proteins showed 1‐ to 3‐fold up‐regulation in leaf sheath, in response to 50 mM NaCl for 24 h. Among these, three proteins were unidentified (LSY081, LSY262 and LSY363) while five proteins were identified as fructose bisphosphate aldolases, photosystem II (PSII) oxygen evolving complex protein, oxygen evolving enhancer protein 2 (OEE2) and superoxide dismutase (SOD). The maximum expression levels of seven proteins were at 24 h. Their expression declined after 48 h of 50 mM NaCl treatment. In contrast, SOD maintained its elevated expression throughout these conditions. The increased expression of proteins seen in the 50 mM NaCl treatment group was less pronounced in the groups receiving 100 or 150 mM NaCl for 24 h. The expression of SOD was a common response to cold, drought, salt and abscisic acid (ABA) stresses while the expression of LSY081, LSY363 and OEE2 was enhanced by salt and ABA stresses. LSY262 was expressed in leaf sheath and root, while fructose bisphosphate aldolases, PSII oxygen evolving complex protein and OEE2 were expressed in leaf sheath and leaf blade. LSY363 was expressed in leaf sheath but was below the level of detection in leaf blade and root. These results indicate that specific proteins expressed in specific regions of rice show a coordinated response to salt stress.

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.…”

Proteomic responses of rice young panicles to salinity

“…Proteomic approach has been applied to study rice responses to salt stress at seedling stage [7,[12][13][14]. The saltresponsive proteins in the roots of the salt-tolerant rice variety Pokkali and the salt-sensitive variety IR29 were studied previously [7].…”

Research on the Rice Proteome: The Contribution of Proteomics Technology in the Creation of Abiotic Stress-Tolerant Plants

“…Although eight of these are known salt-stress response proteins, the majority have not been reported in the literature. In proteomic studies, the level of different SOD isoforms were found up-regulated under drought [4,49], salt [1,44], and ozone [2,15]. SOD activity, determined by multigene family, is changing under different environmental conditions.…”

“…Whereas four of the changed proteins had been previously identified as salt stress-responsive proteins, six were novel: UDP-glucose pyrophosphorylase, cytochrome c oxidase subunit 6b-1, glutamine synthetase root isozyme, putative nascent polypeptide-associated complex alpha chain, putative splicing factor-like protein, and putative actin-binding protein. The reports of Abbasi and Komatsu [1] and Yan et al [57], taken together, show that specific proteins that have enhanced abundances in distinct regions of the rice plant are involved in a coordinated response to salt stress. Dooki et al [12] employed a proteomic approach to further elucidate the mechanism of responses of plants to salt at an early reproductive stage.…”

“…Salt-tolerant transgenic rice plants have been produced by using a wide range of different genes, and transcript profiling by microarray-and macroarray-based methods has opened a route to the discovery of novel salt-stress mechanisms in rice: information from comparative genomics is turning out to be of vital importance in this respect [48]. Abbasi and Komatsu [1] adopted a proteomics approach to identify proteins that increase in abundance in leaf sheathes, roots, and leaf blades of 2-week-old rice seedlings subjected to salt stress. In leaf sheathes exposed to NaCl, eight proteins consistently showed significant changes.…”