Differential Accumulation of Transcripts for ACC Synthase Homologs in Etiolated Mung Bean Hypocotyle in Response to Li

다국어 초록 (Multilingual Abstract)

In mung bean (Vigna radiate), 1-aminocyclopropane-1-carboxylate synthase (ACS) is encoded by a multigene family that comprises at least seven members. Their expression is induced by hormones, developmental signals, inhibition of protein synthesis, or stress. We performed an RT-PCR assay to understand the differential accumulation of transcripts for ACC synthase homologs as a response to Li^+ in etiolated mung bean hypocotyls. Treating the seedlings with LiCl caused inductions of the ACS1, ACS4, ACS5, ACS6, and ACS7 genes. The induction level of ACS7 was particularly high. This effect on ACS7 expression was specific, lasting more than 8 h after the treatment To understand the relationship of this Li^+ action with the phosphoinositide (PI) second messenger system, we examined the effect of Ca^2+ treatment on Li^+ -induction of the ACS7 gene. Because Ca_2+ did not reverse the Li^+ effect, we suggest that regulation of the ACS7 gene by Li^+ in the mung bean may not involve the PI system.