Molecular characterisation of an S-like RNase of Nicotiana alata that is induced by phosphate starvation.
We characterised a cDNA encoding an S-like RNase (RNase NE) from the styles of the self-incompatible plant, Nicotiana alata. RNase NE is 86% identical to an extracellular RNase from tomato cell cultures, RNase LE. DNA hybridisation experiments indicate that there are ca. 5-6 sequences related to RNase NE in the N. alata genome and that RNase NE is not linked to the self-incompatibility (S) locus. RNase NE is expressed in the styles, petals and immature anthers but not in the vegetative tissues of N. alata plants under normal growth conditions. Under phosphate-limited conditions, RNase NE expression is induced in roots but not leaves of N. alata. A transcript hybridising to RNase NE is also induced in N. plumbaginifolia cell cultures in response to phosphate starvation. RNase NE is likely to play a role in the response of N. alata to phosphate limitation, possibly by scavenging phosphate from sources of RNA in the root environment. We also discuss the evolutionary relationships between the S- and S-like RNase genes in plants.
Dodds
P N
PN
Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria, Australia.
Clarke
A E
AE
Newbigin
E
E
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000235:genetics; D004722:Endoribonucleases / Q000235:genetics*; D004790:Enzyme Induction; D015971:Gene Expression Regulation, Enzymologic; D017343:Genes, Plant; D007438:Introns; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism; D010802:Phylogeny; D010947:Plants, Toxic; D012260:Ribonucleases / Q000235:genetics*; D014026:Nicotiana / Q000201:enzymology*
D017931:DNA Primers; D018076:DNA, Complementary; D010710:Phosphates; D004722:Endoribonucleases; D012260:Ribonucleases; C100993:RNase NE