Molecular Cloning and Differential Expression of the Maize Ferredoxin Gene Family

Abstract

In maize (Zea mays L.), four ferredoxin (Fd) Recently, it was reported that nonphotosynthetic organs, such as maize roots and mesocotyls (12), and radish white roots (25) also contained Fd. These Fds are most probably involved in electron transfers from pyridine dinucleotides to

Plastid Import and Iron-Sulfur Cluster Assembly of Photosynthetic and Nonphotosynthetic Ferredoxin Isoproteins in Maize

“…Plasmid carrying the insert with the desired orientation was selected, and a short region from HindIII to SmaI in the polylinker sites of pGEM3Z was deleted to remove initiation and termination codons present between the SP6 transcription start site and initiation codon of the Fd cDNA. The Sau3AI/XhoI fragment containing the coding region of Fd III was obtained from pFD3-1, a full-length cDNA 154 base pairs longer in the 5' region than pFD3 reported previously (9). The fragment was inserted into pGEM4Z after cleavage with BamHI and Sall.…”

“…Whether the constitutive Fds are also localized in plastids is not known. Sequencing of Fd cDNAs has shown that Fd I and Fd III have precursors with an amino-terminal extension of 52 and 55 amino acid residues, respectively, but that the presequences share little sequence homology (9). These results imply that Fd III may be localized to a specific organelle, but do not necessarily lead us to the conclusion that Fd III is a plastid protein.…”

“…They are also present in nonphotosynthetic organs such as roots (12,25,27), and it is generally assumed that nonphotosynthetic Fds are probably involved in electron transfer from pyridine dinucleotides to some Fdlinked enzymes (25,27). Although nonphotosynthetic Fds differ considerably from those of photosynthetic Fds (9,28), it is still speculative whether any functional difference exists between the two types of Fds.…”

“…We reported previously that maize has at least four Fd isoproteins (Fd I to Fd IV), which are divided into two groups based on their organ distributions and light responses (9,12). Fd I and Fd II are distributed only in leaves, being localized in chloroplasts, and their steady-state levels of protein and mRNA increase in a light-inducible manner.…”

Preface: ferredoxin

“…Work by the Hase laboratory had been fundamental in establishing that photosynthetic organisms contain multiple different kinds of ferredoxin (Hase et al 1991) and proving that these ferredoxins differed in electron transfer properties Yonekura-Sakakibara et al 2000). In addition to supporting NADP + reduction by the ferredoxin:NADP + reductase (FNR), ferredoxin is capable of donating electrons to multiple other enzymes in a wide range of pathways (Hanke and Mulo 2013).…”