ISSN:
1432-2048
Keywords:
mRNA levels
;
Legumin
;
Lectin
;
Pisum (storage-protein genes)
;
Posttranscriptional regulation
;
Seed storage protein
;
Transcription in isolated nuclei
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract At least three classes of legumin, encoded by the gene families legA, legJ and legS, and a lectin, encoded by a single gene, accumulate in the developing cotyledons of Pisum sativum L. Transcription rates for the genes encoding these proteins were measured in nuclei isolated from cotyledons at 12 and 16 days after flowering (DAF). The steady-state levels of the corresponding mRNA species were also measured in absolute terms throughout cotyledon development, from 8–9 to 28 DAF. When transcription rates and steady-state mRNA levels of the different gene families are compared, there is little correlation. This indicates a posttranscriptional regulation of the level of expression of these storage proteins in the developing cotyledons. Expression of the legumin genes is known to be seed-specific, whereas expression of the lectin gene is found in both seed and root. When transcription rates were measured in leaf nuclei the levels of legumin and lectin transcripts detected approached background levels, indicating that these genes are either inactive or transcribed at very low levels in leaves; however, the rate of transcription of the chlorophyll a/b-binding protein gene was high. This points to transcriptional control as the major factor in the organ-specificity of legumin and lectin expression.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00391072
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