ISSN:
1573-5028
Keywords:
C4 photosynthesis
;
C3–C4 intermediates
;
Flaveria
;
NADP-malic enzyme
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract To study the control of enhanced synthesis of enzymes associated with C4 photosynthesis relative to non-C4 plants, we investigated the expression of NADP-malic enzyme (NADP-ME) in different photosynthetic types ofFlaveria. Complementary DNA clones encoding NADP-ME were constructed using poly(A)+ RNA from leaves ofFlaveria trinervia (C4) andF. linearis (C3–C4) and identified by homology to a cDNA clone (500 bp) encoding NADP-ME from maize (Zea mays L. [39]). The sequence of one clone from each species was determined. TheFlaveria clones were 90% homologous over a 564 nucleotide region encoding the carboxy terminal end of the derived polypeptide; sequence similarity to the maize transcript in this region was 71%. BothFlaveria clones detected a 2/3 kb transcript by hybridization to poly(A)+ RNA from expanding leaves ofF. trinervia, F. linearis andF. pringlei (C3). The level of transcripts paralleled previously observed NADP-ME activity and abundance differences determined in these species, suggesting that control of the expression of NADP-ME in different photosynthetic types is predominantly at the transcriptional/post-transcriptional level. Southern analysis of genomic DNAs fromF. trinervia, F. linearis andF. pringlei indicated a low copy number for this gene in all three species.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00040632
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