Molecular Characterization of cDNA Encoding Oxygen Evolving Enhancer Protein 1 Increased by Salt Treatment in the Mangrove Bruguiera gymnorrhiza

Abstract

Young plants of the common Okinawa mangrove species Bruguiera gymnorrhiza were transferred from freshwater to a medium with seawater salt level (500 mM NaCl). Two-dimensional gel electrophoresis revealed in the leaf extract of the plant a 33 kDa protein with pI 5.2, whose quantity increased as a result of NaCl treatment. The N-terminal amino acids sequence of this protein had a significant homology with mature region of oxygen evolving enhancer protein 1 (OEE1) precursor. The cloning of OEE1 precursor cDNA fragment was carried out by means of reverse transcription-PCR (RT-PCR) using degenerated primers. Both 3'- and 5'-regions were isolated by rapid amplification of cDNA ends (RACE) method. The deduced amino acid sequence consisted of 322 amino acids and was 87% identical to that of Nicotiana tabacum. In B. gymnorrhiza, the predicted amino acid sequence of the mature protein starts at the residue number 85 of the open reading frame. The first 84-amino acid residues correspond to a typical transit sequence for the signal directing OEE1 to its appropriate compartment of chloroplast. The expression of OEE1 was analyzed together with other OEE subunits and D1 protein of photosystem II. The transcript levels of all the three OEEs were enhanced by NaCl treatment, but the significant increase of D1 protein was not observed.

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

“…All the RuBisCO proteins (spots 1-5) are also marked in pink for reference. Proteomics approach to detect low N-responsive proteins in rice (Sugihara et al, 2000). These proteins have been previously shown to be induced by salt stress but reduced by ozone and sulfur dioxide fumigation (Agrawal et al, 2002;Rakwal et al, 2003).…”

Molecular Cloning of Oxygen-Evolving Enhancer Genes Induced by Salt Treatment in a Halophyte,Salicornia europaeaL.

“…Then, the elevated level was maintained up to 3 d of treatment. In contrast to this result, the levels of transcripts corresponding to OEE2 and OEE3 were did not significantly change during the 3 d. In Bruguiera gymnorrhiza, the transcription level of OEE1 was increased by 500 mM NaCl (seawater salt level) treatment similar to that of Salicornia OEE1 (Sugihara et al, 2000). OEE1 is essential for oxygen evolving activity and PSII stability, and the expression of OEE1 is also considered to be the rate-limiting step in the assembly of the PSII subunit (Mizobuchi and Yamamoto 1989).…”

“…On the other hand, the transcript levels of OEE2 and OEE3 in Bruguiera gymnorrhiza were increased by treated with 500 mM NaCl (Sugihara et al, 2000) unlike Salicornia OEE2 and 3. According to Thornton et al (2004), OEE1 (PsbO) was the only extrinsic protein conserved between species, while the protein nature of OEE2 (PsbP) and OEE3 (PsbQ) greatly differs with the species, indicating that OEE2 and 3 have changed considerably during evolution.…”

“…However, genes and proteins related to PSII complex in halophytes have not been fully identified, and the functions of those genes and proteins in halophytes are also not yet fully understood. Regarding OEEs in halophytes, the full-length cDNA sequence of OEE1 was recently identified from mangrove species Bruguiera gymnorrhiza based on the proteome analysis (Sugihara et al, 2000). Interestingly, Bruguiera OEE1, 2 and 3 mRNA were induced by 500 mM NaCl treatment, showing that Bruguiera OEEs may relate to the maintenance of PSII damaged by NaCl treatment.…”

Comparative Lipid Isolation Protocols from Rhizophora mucronata L. of Dharmadam Estuary and Lipid Profiling in the Context of a Non Mangrove Mangifera indica

“…These salt-tolerant plants (mangroves) have advanced mechanisms to cope with the harmful after effects of salinity stress. Despite the fact that stress tolerance mechanisms of plants materialized to be composite and divergent, various lines of mechanisms have been proposed for their salt tolerance properties: osmotic potential across the cell membrane is balanced by the accumulation of low molecular weight osmolytes, such as glycine betaine, sugar alcohols and proline [2][3][4] and stress induced damages get repaired by the production of stress-inducible proteins and other biomolecules, of which vivid physiological function is yet to become apparent [5][6][7][8][9].…”