Effects of free proline accumulation in petunias under drought stress.

Petunias (Petunia hybrida cv. 'Mitchell') accumulate free proline (Pro) under drought-stress conditions. It is therefore believed that Pro acts as an osmoprotectant in plants subjected to drought conditions.

Analysis of salt-stress-inducible ESTs isolated by PCR-subtraction in salt-tolerant rice.

To clarify the mechanisms of stress tolerance in rice and to search for rice genes associated with these mechanisms, we analyzed genes induced by a high salinity treatment using the PCR-subtractive hybridization method (PCR-subtraction). Seedlings of the salt-tolerant rice cultivar Dee-geo-woo-gen (DGWG) were either treated with 250 mM NaCl for 5 h or left untreated, and PCR-subtraction was then performed using the untreated (control) plants as a driver and the NaCl-treated plants as a tester. We obtained 384 clones of tester-specific cDNAs as salt-inducible candidates.

Purification, characterization, and gene expression of all sigma factors of RNA polymerase in a cyanobacterium.

The expression of RNA polymerase (RNAP) sigma factor genes and proteins was characterized as a first step toward understanding their functions in a unicellular cyanobacterium Synechocystis sp. PCC 6803, which can perform photosynthesis. All nine sigma factors (group 1, SigA; group 2, SigB to SigE; and group 3, SigF to SigI) and each RNAP core subunit (RpoA, RpoB, RpoC1 and RpoC2) were overproduced and purified from Escherichia coli cells, then polyclonal antibodies were prepared.