摘要

In plant respiratory chains, alternative pathways for NAD(P)H oxidation are mediated by type II NAD(P)H dehydrogenases belonging to the NDA, NDB, and NDC families. For the latter type, Arabidopsis thaliana contains a single gene, NDC1, whose functional role has not previously been analyzed in the plant. We found that A. thaliana NDC1 is alternatively spliced. Four base pairs at the 3%26apos; end of intron 5 are spliced out in NDC1-1, but retained in the NDC1-2 mRNA, which therefore contains a truncated reading frame. Both variants are conserved in dicotyledonous and monocotyledonous plants and their relative abundance varies between organs and in response to light. Three analyzed NDC1 T-DNA insertion lines all displayed an early bolting phenotype. A dramatic upregulation of ACTIN2 was characteristic of two lines containing T-DNA inserts upstream of intron 5, whereas a line with an insertion downstream of the NDC1-2 reading frame had an ACTIN2 expression level identical to the wildtype. Thus, the alternatively spliced 5%26apos; domain of NDC1 strongly influences the expression of the functionally unrelated ACTIN2, which is a common reference gene for quantitative RT-PCR. Also for other reference genes, strong expressional effects were observed when comparing various mutants and wildtypes in microarray databases.

  • 出版日期2012-2