S. Thoiron et Jf. Briat, Differential expression of maize sugar responsive genes in response to iron deficiency, PL PHYS BIO, 37(10), 1999, pp. 759-766
Substractive screening of a root cDNA library from Fe deficient maize plant
s led to isolate a Sus1 cDNA encoding for sucrose synthase (UDP-glucose:D f
ructose 2-alpha-D-glycosyl-transferase, EC 2.4.1.13). Northern analysis sho
wed that Sus1 mRNA abundance increased in response to iron deficiency in ma
ize roots, whereas abundance of two other sugar responsive transcripts, Sh1
sucrose synthase and pZSS6 metallothionein mRNAs, decreased under these co
nditions. These mRNA abundance variations have been correlated to increased
sugar concentrations in iron deficient maize roots. In contrast in maize l
eaves, glucose and fructose, but not sucrose content, decreased in response
to iron deficiency, mRNA abundance of Sus1, but also of HI and CSII encodi
ng for a histone and a cytoplasmic ribosomal proteins, respectively, was de
creased in maize iron deficient leaf sheaths compared to iron sufficient pl
ants. The general conclusion of this work points out a differential alterat
ion of sugar metabolism and sugar responsive gene expression between leaves
and roots in response to iron deficiency. (C) 1999 Editions scientifiques
et medicales Elsevier SAS.