A cDNA clone, designated Am-FaPS-1 (1310 bp), was isolated from callus culture derived from the leaf tissues of Aquilaria microcarpa. This gene contains an open reading frame encoding the protein of 342 amino acid residues with high homology to farnesyl diphosphate synthase from various plant sources. An appreciable increase in the transcriptional level of Am-FaPS-1 was reproducibly observed by the exposure of the cell culture to methyl jasmonate. The expression activity of the gene was also elevated when the cells were treated with yeast extract and Ca(2+)-ionophore A23187. These results suggest that Am-FaPS-1 and its translate play roles in methyl jasmonate- and yeast extract-induced responses of A. microcarpa, and Ca(2+) functions as an important messenger molecule in these processes. This set of the results would support our hypothesis that the activation of Ca(2+)-cascade evoked by the elevation of cytoplasmic Ca(2+) concentration is an essential early event in methyl jasmonate-induced responses of higher plant cells.

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Changes in the polypeptide composition of chloroplasts were investigated during germination of green spores of the fern Osmunda japonica. The polypeptide composition of chloroplasts was appreciably changed during a germination time course of 48 h. Levels of five polypeptides with apparent molecular masses of 47, 44, 42, 22 and 18.5 kDa in the soluble fraction of chloroplasts and three polypeptides with molecular masses of 24, 22 and 15 kDa in the thylakoid membranes decreased during germination. In contrast, no decrease of chloroplast polypeptides was observed in the spores incubated with cycloheximide for 48 h. A new 22‐kDa protein was isolated from thylakoid membranes of spores and the amino‐terminal sequence of the purified protein was determined. High levels of alanine and glycine were found in the basic protein (pl > 10.3). This protein, with a native molecular mass of 80 kDa, was characterized by a subunit band observed at a molecular mass of 22 kDa on SDS‐PAGE and by the disappearance of the band during spore germination. Protease activity against the 22‐kDa protein was observed in an extract prepared from chloroplasts of quiescent spores. A hypothetical cytosolic proteinaceous factor is implicated in the regulation of protein degradation in chloroplasts.