A ubiquitously expressed MADS-box gene from Nicotiana tabacum

Experiments in Antirrinum majus, Arabidopsis thaliana and Petunia hybrida have demonstrated that putative transcription factors of the so-called MADS-box family play an important role in determining floral organ identity. Such regulatory genes are transiently expressed in small numbers of cells in the floral apex. Here we describe the isolation of a cDNA from Nicotiana tabacum coding for a MAD S-box protein which is expressed in both the floral and vegetative organs of the plant

Characterization of Two cDNAs Encoding Mitochondrial Lipoamide Dehydrogenase from Arabidopsis

In contrast to peas (Pisum sativum), where mitochondrial lipoamide dehydrogenase is encoded by a single gene and shared between the α-ketoacid dehydrogenase complexes and the Gly decarboxylase complex, Arabidopsis has two genes encoding for two mitochondrial lipoamide dehydrogenases. Northern-blot analysis revealed different levels of RNA expression for the two genes in different organs; mtLPD1 had higher RNA levels in green leaves compared with the much lower level in roots. The mRNA formtLPD2 shows the inverse pattern. The other organs examined showed nearly equal RNA expressions for both genes. Analysis of etiolated seedlings transferred to light showed a strong induction of RNA expression for mtLPD1 but only a moderate induction of mtLPD2. Based on the organ and light-dependent expression patterns, we hypothesize thatmtLPD1encodes the protein most often associated with the Gly decarboxylase complex, and mtLPD2 encodes the protein incorporated into α-ketoacid dehydrogenase complexes. Due to the high level of sequence conservation between the two mtLPDs, we assume that the proteins, once in the mitochondrial matrix, are interchangeable among the different multienzyme complexes. If present at high levels, one mtLPD might substitute for the other. Supporting this hypothesis are results obtained with a T-DNA knockout mutant,mtlpd2, which shows no apparent phenotypic change under laboratory growth conditions. This indicates that mtLPD1 can substitute for mtLPD2 and associate with all these multienzyme complexes.This article is from Plant Physiology 127, no. 2 (October 2001): 615–623, doi:10.1104/pp.010321.</p

Characterization of Two cDNAs Encoding Mitochondrial Lipoamide Dehydrogenase from Arabidopsis

In contrast to peas (Pisum sativum), where mitochondrial lipoamide dehydrogenase is encoded by a single gene and shared between the α-ketoacid dehydrogenase complexes and the Gly decarboxylase complex, Arabidopsis has two genes encoding for two mitochondrial lipoamide dehydrogenases. Northern-blot analysis revealed different levels of RNA expression for the two genes in different organs; mtLPD1 had higher RNA levels in green leaves compared with the much lower level in roots. The mRNA for mtLPD2 shows the inverse pattern. The other organs examined showed nearly equal RNA expressions for both genes. Analysis of etiolated seedlings transferred to light showed a strong induction of RNA expression for mtLPD1 but only a moderate induction of mtLPD2. Based on the organ and light-dependent expression patterns, we hypothesize that mtLPD1 encodes the protein most often associated with the Gly decarboxylase complex, and mtLPD2 encodes the protein incorporated into α-ketoacid dehydrogenase complexes. Due to the high level of sequence conservation between the two mtLPDs, we assume that the proteins, once in the mitochondrial matrix, are interchangeable among the different multienzyme complexes. If present at high levels, one mtLPD might substitute for the other. Supporting this hypothesis are results obtained with a T-DNA knockout mutant, mtlpd2, which shows no apparent phenotypic change under laboratory growth conditions. This indicates that mtLPD1 can substitute for mtLPD2 and associate with all these multienzyme complexes