ISSN:
1432-2048
Keywords:
Amylase
;
Deepwater rice
;
Ethylene and internode growth
;
Gibberellin and internode growth
;
Internode growth
;
Oryza (amylases and growth)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Isoelectrofocusing, product analysis, thermal denaturation studies and affinity chromatography on cycloheptaamylose-Sephadex were used to identify the amylolytic enzymes in internodes of deepwater rice (Oryza sativa L.). Amylolytic activity in internodes of deepwater rice consists of α-amylase (sometimes separated into two isoforms) and of β-amylase. During submergence of whole plants, α-amylase activity increases in young, growing internodes, but β-amylase activity declines. Although non-growing, mature internodes contain higher levels of β-amylase than do the elongating younger internodes, the effect of submergence on amylase activities in both tissues follows the same trend. Submergence, gibberellic acid (GA3) and ethylene all promote α-amylase activity in growing and non-growing internodes of excised deepwater-rice stem sections. Inhibitor studies showed that submergence and ethylene promote α-amylase activity in the absence of endogenous gibberellin (GA), and GA3 enhances α-amylase activity when ethylene action is inhibited. Therefore, ethylene and GA appear to increase α-amylase activity independently of each other. Enhanced α-amylase activities are probably responsible for the mobilization of carbohydrates which are needed to support internode elongation during submergence of deepwater rice.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00403036
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