Developmental regulation of expression of the malate synthase gene in transgenic plants
Graham, IA and Smith, LM and Leaver, CJ and Smith, SM, Developmental regulation of expression of the malate synthase gene in transgenic plants, Plant Molecular Biology, 15, (4) pp. 539-549. ISSN 0167-4412 (1990) [Refereed Article]
The cucumber malate synthase (MS) gene, including 1856 bp of 5' non-transcribed sequence, has been
transferred into Petunia (Mitchell) and Nicotiana plumbaginifolia plants using an Agrobacterium binary
vector. The transferred gene is found in variable copy number in different transformants, and is stably
transmitted in each case as a single Mendelian character. Transgene mRNA accumulates in the seedling
during the first three days of germination, then declines in amount as the cotyledons emerge from the seed.
The decline is more pronounced in light-grown seedlings than in dark-grown seedlings. Expression of the
MS transgene is also detected at a low level in petals of transformed Petunia plants. In these respects
the pattern of MS gene expression is similar in cucumber and in transformed plants, showing that the
transferred DNA fragment contains a functional MS gene. A 1076 bp fragment of 5' sequence was linked
to the beta-glucuronidase reporter gene and transferred into Nicotiana, where it was shown to direct temporal
and spatial patterns of expression similar to that of the complete MS gene. However, histochemical
localisation of beta-glucuronidase activity demonstrated that the chimaeric gene is expressed not only in
cotyledons oftransgenic plants, but also in endosperm and some hypocotyl cells during early germination.
The relevance of these findings to the control of malate synthase gene expression is discussed.