ISSN:
1432-2048
Keywords:
Key words: Abscisic acid (analog)
;
α-Amylase I-1
;
Gene expression (RAmy1A)
;
Oryza (α-amylase
;
sugar accumulation)
;
Sugar accumulation (rice)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract. The effects of (+)-8′,8′,8′-trifluoroabscisic acid (trifluoro-ABA) on α-amylase expression were studied in rice embryoless half-seeds, scutella, and suspension-cultured cells derived from the embryo, and the effects of the analog on sugar accumulation were also studied in scutella and suspension-cultured cells. Treatment with (+)-trifluoro-ABA strongly inhibited the gibberellic acid-inducible expression of α-amylase I-1 encoded by RAmy1A in the aleurone layers of embryoless half-seeds at the levels of transcription, protein synthesis, and enzyme activity. It was also found that (+)-trifluoro-ABA stimulated (i) the uptake of glucose from the incubation medium and (ii) the synthesis of sucrose in scutellar tissues and suspension-cultured cells of rice. The biological activity of (+)-trifluoro-ABA was found to be more potent and persistent than that of natural ABA. We further examined the effects of trifluoro-ABA on the expression of α-amylase I-1 in scutellar tissues and suspension-cultured cells. It was found that (+)-trifluoro-ABA did not inhibit the formation of α-amylase I-1 in the absence of external glucose. However, glucose and (+)-trifluoro-ABA cooperatively suppressed the formation of α-amylase I-1. Judging from these results, we conclude that the regulatory mechanism for the expression of α-amylase I-1 in the scutellar epithelium is distinguishable from that operating in the aleurone layer.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004250050326
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