In:
Plant Physiology, Oxford University Press (OUP), Vol. 117, No. 3 ( 1998-07-01), p. 939-948
Abstract:
NADP-dependent isocitrate dehydrogenase (NADP-ICDH) activity is increased in roots ofEucalyptus globulus subsp. bicostata ex Maiden Kirkp. during colonization by the ectomycorrhizal fungusPisolithus tinctorius Coker and Couch. To investigate the regulation of the enzyme expression, a cDNA (EgIcdh) encoding the NADP-ICDH was isolated from a cDNA library of E. globulus-P. tinctorius ectomycorrhizae. The putative polypeptide sequence of EgIcdh showed a high amino acid similarity with plant NADP-ICDHs. Because the deduced EgICDH protein lacks an amino-terminal targeting sequence and shows highest similarity to plant cytosolic ICDHs, it probably represents a cytoplasmic isoform. RNA analysis showed that the steady-state level ofEgIcdh transcripts was enhanced nearly 2-fold in ectomycorrhizal roots compared with nonmycorrhizal roots. Increased accumulation of NADP-ICDH transcripts occurred as early as 2 d after contact and likely led to the observed increased enzyme activity. Indirect immunofluorescence microscopy indicated that NADP-ICDH was preferentially accumulated in the epidermis and stele parenchyma of nonmycorrhizal and ectomycorrhizal lateral roots. The putative role of cytosolic NADP-ICDH in ectomycorrhizae is discussed.
Type of Medium:
Online Resource
ISSN:
1532-2548
,
0032-0889
DOI:
10.1104/pp.117.3.939
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
1998
detail.hit.zdb_id:
2004346-6
detail.hit.zdb_id:
208914-2
SSG:
12
