Oxygen regulation of uricase and sucrose synthase synthesis in soybean callus tissue is exerted at the mRNA level
✍ Scribed by Zhong-tian Xue; Knud Larsen; Bjarne U. Jochimsen
- Publisher
- Springer
- Year
- 1991
- Tongue
- English
- Weight
- 841 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0167-4412
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✦ Synopsis
The effect of lowering oxygen concentration on the expression of nodulin genes in soybean callus tissue devoid of the microsymbiont has been examined. Poly(A)+ RNA was isolated from tissue cultivated in 4% oxygen and in normal atmosphere. Quantitative mRNA hybridization experiments using nodule-specific uricase (Nodulin-35) and sucrose synthase (Nodulin-100) cDNA probes confirmed that the synthesis of the uricase and sucrose synthase is controlled by oxygen at the mRNA level. The steady-state levels of uricase and sucrose synthase mRNA increased significantly (5-6- and 4-fold respectively) when the callus tissue was incubated at reduced oxygen concentration. Concomitant with the increase in mRNA level a 6-fold increase in specific activity of sucrose synthase was observed. Two messengers representing poly-ubiquitin precursors also responded to lowering the oxygen concentration. The increase was about 5-fold at 4% oxygen. No expression at atmospheric oxygen or in response to low oxygen was observed when using cDNA probes for other nodulin genes such as leghemoglobin c3, nodulin-22 and nodulin-44.