Reference "Isolation of cDNA clones for genes showing enhanced expression in barley leaves during dark-induced senescence as well as during senescence under field conditions"

Reference ID

8896

Title

Isolation of cDNA clones for genes showing enhanced expression in barley leaves during dark-induced senescence as well as during senescence under field conditions

Source

Planta, 1997, vol. 203, pp. 332-340

Authors (2)

Kleber-Janke-T

Krupinska-K

Abstract

Senescence of barley (Hordeum vulgare L. cv. Carina) primary foliage leaves was
induced by transfer of the plants into darkness for 2 d. Under these conditions
senescence was characterized by a light-reversible decline in the efficiency of
photosystem II, and in chlorophyll and protein contents. To isolate senescence-
associated genes a differential display of cDNA fragments amplified from
reversely transcribed RNA was employed. By this method, gene expression in
leaves of control plants collected at the onset of the dark period was compared
with gene expression in senescing leaves collected at the end of the extended
dark period. The expression of the genes represented by various differentially
displayed cDNA fragments was examined by Northern blot hybridizations with RNA
derived from primary foliage leaves before and after induction of senescence by
darkness. In order to test whether these genes with enhanced expression during
dark-induced senescence also show enhanced expression during natural senescence,
Northern blot hybridizations were carried out with RNA samples prepared from
flag leaves of barley plants during maturation and senescence under field
conditions. Five of the cDNA fragments representing transcripts associated with
dark-induced senescence, as well as with natural senescence, were selected as
probes for screening a cDNA library from senescent flag leaves. With one probe a
larger cDNA including a complete open reading frame with homology to the
sequence of a known proteinase inhibitor was found. Another cDNA isolated by
this means showed high sequence similarity with a gene coding for a 4-
hydroxyphenylpyruvate dioxygenase. The other three larger cDNA clones isolated
by this procedure so far do not show significant homologies with known
sequences.